by Judith Curry
I spent the 1990’s conducting research on the climate dynamics of the Arctic Ocean, and then moved onto other things circa 2002. My interest in the Arctic has recently been reinvigorated by the increasing societal implications of reduced sea ice extent in terms of security issues, the prospect of a northern sea route, implications for resource exploration and extraction, and adaptation issues for coastal villages along the Arctic Ocean coast.
This multi-part series will begin with an overview of what we know about the climate dynamics of the Arctic Ocean sea ice.
Background
The definitive paper on the history of Arctic sea ice is this recent paper by Polyak et al.
History of sea ice in the Arctic
Leonid Polyak, Richard B. Alley, John T. Andrews, Julie Brigham-Grette, Thomas M. Cronin, Dennis A. Darby, Arthur S. Dyke, Joan J. Fitzpatrick, Svend Funder, Marika Holland, Anne E. Jennings, Gifford H. Miller, Matt O’Regan, James Savelle, Mark Serreze, Kristen St. John, James W.C. White, Eric Wolff
Quaternary Sciene Reviews 29 (2010) 1757–1778
Abstract. Arctic sea-ice extent and volume are declining rapidly. Several studies project that the Arctic Ocean may become seasonally ice-free by the year 2040 or even earlier. Putting this into perspective requires information on the history of Arctic sea-ice conditions through the geologic past. This information can be provided by proxy records from the Arctic Ocean floor and from the surrounding coasts. Although existing records are far from complete, they indicate that sea ice became a feature of the Arctic by 47 Ma, following a pronounced decline in atmospheric pCO2 after the Paleocene–Eocene Thermal Optimum, and consistently covered at least part of the Arctic Ocean for no less than the last 13–14 million years. Ice was apparently most wide- spread during the last 2–3 million years, in accordance with Earth’s overall cooler climate. Nevertheless, episodes of considerably reduced sea ice or even seasonally ice-free conditions occurred during warmer periods linked to orbital variations. The last low-ice event related to orbital forcing (high insolation) was in the early Holocene, after which the northern high latitudes cooled overall, with some superimposed shorter- term (multidecadal to millennial-scale) and lower-magnitude variability. The current reduction in Arctic ice cover started in the late 19th century, consistent with the rapidly warming climate, and became very pronounced over the last three decades. This ice loss appears to be unmatched over at least the last few thousand years and unexplainable by any of the known natural variabilities.
Full paper available online [link]
Additional background material is available in the CCSP Synthesis and Assessment Report on Arctic Climate Change
Millennial to decadal variability
The current interglacial is of particular interest in terms of understanding the recent sea ice variability and decline, particularly in terms of millennial to decadal varaibility. The relevant text from Polyak et al. is reproduced here (note, for readability I have removed the reference citations):
4.3.2. Suborbital variability
Owing to relatively high sedimentation rates at continental margins, paleoceanographic environments and ice drift patterns can be constructed on suborbital (millennial to decadal) scales from some sedimentary records. These high-resolution records reveal a considerable complexity in the system including forcings operating on suborbital scales (such as solar activity, volcanic eruptions, and atmospheric and oceanic circulation), changes in seasonality, and links with lower latitudes. Thus, the periodic, centennial-scale influx of large numbers of iron-oxide grains from the Siberian shelves to the northern Alaska margin has been linked to a reduced Beaufort Gyre and a shift in the Trans-Polar Drift toward North America. Under present conditions such a shift occurs during a positive phase of the Arctic Oscillation. The finding that similar changes may have occurred on century to millennial-scales argues for the existence of longer-term atmospheric variability in the Arctic than the decadal Arctic Oscillation observed during the last century.
Variations in the volumes of IRD in the subarctic North Atlantic indicate several cooling and warming intervals during Neoglacial time (late Holocene), similar to the so-called ‘‘Little Ice Age’’ and ‘‘Medieval Warm Period’’ cycles of greater and lesser areas of sea ice known from the last millennium. Southward polar-water excursions have been reconstructed at several sites in this region as multi-century to multidecadal-scale variations superimposed on the longer-term trends. Millennial variations in ice conditions have also been suggested for the Barents Sea reflecting changes in atmospheric and oceanic interactions between the North Atlantic and the Arctic.
In the Arctic centennial climate variability during the cooling of the last 2 kyr was more subdued than in the Northern hemisphere as a whole, although major temperature anomalies like the warmings around 1000 and 500 A.D. can be discerned. A final peak of bowhead bones appears to have culminated shortly prior to 1000 A.D. in the Beaufort Sea and somewhat later in the eastern CAA [Canadian Arctic Archipelago], suggesting the possibility of temporarily open channels. This inference is consistent with the IP25 record, which indicates a relatively decreased spring ice occurrence between ca 1.2 and 0.8 ka (800– 1200 A.D.). At the end of this time the bowhead-hunting Thule Inuit (Eskimos) expanded eastward out of the Bering Sea region and ultimately spread to Greenland and Labrador. The subsequent decline of bowhead abundances in the CAA is consistent with the abandonment of the high Arctic of Canada and Greenland by bowhead hunters, while Thule living in more southern Arctic regions increasingly focused on alternate food resources. The warming event around 1500 A.D. is identified by climatic simulations in the Atlantic sector of the Arctic and is explained by the internal variability of atmospheric circulation. The subsequent cooling culminated in the ‘‘Little Ice Age’’, between ca 1600 and 1850 AD, when ice conditions in the high- Arctic remained especially prohibitive for navigation.
Historical observations in the Nordic Seas since mid-18th century indicate multidecadal oscillations in ice extent super- imposed on an overall trend of retreating ice margin. Similar oscillations, although with somewhat variable frequencies, are inferred for a longer, 800-yr period from an ice- core/tree-ring proxy record. These multidecadal changes are probably related to variability in the North Atlantic thermohaline circulation, but their mechanism is not well understood and may involve a combination of internal variability in the circulation with external factors such as solar and aerosol forcings. No record of similar oscillations prior to the 20th century is known from other parts of the Arctic, although most of the paleo-data series existing to date lack sufficient detail.
Historical sea ice record
With regards to the historical record of sea ice extent, again from Polyak et al:
The composite historical record of Arctic ice margins shows a general retreat of seasonal ice since about 1900, and accelerated retreat of both seasonal and annual ice during the last five decades (Fig. 2a). The most reliable observations are from 1979 onwards, corresponding to the modern satellite era. Patterns of ice-margin retreat may differ between different periods and regions of the Arctic, but the overall retreat trend is clearly larger than decadal-scale variability, consistent with observations and modeling of the 20th-century ice concentrations and water temperatures. The severity of present ice loss can be highlighted by the breakup of ice shelves at the northern coast of Ellesmere Island, which have been stable until recently for at least several thousand years based on geological data. On the basis of satellite records, negative trends in sea-ice extent encompass all months, with the strongest trend in September. As assessed by the U.S. National Snow and Ice Data Center, the September trend over the period 1979–2009 is 11% per decade. Conditions in 2007 serve as an exclamation point on this ice loss. The average September ice extent in 2007 of 4.28 million km2 was the lowest in the satellite record and 23% lower than the previous September 2005 record low of 5.56 million km2. On the basis of an extended sea-ice record, it appears that the September 2007 ice extent is only half of that estimated for the period 1950–1970 based on the Hadley Center sea ice and sea-surface temperature data set (HadlSST)). While the ice extent rebounded slightly in September 2008 and 2009, these months rank second and third lowest in the satellite record, respectively.
Many factors may have contributed to this ice loss, such as general Arctic warming, extended summer melt season, and effects of the changing phase of large-scale atmospheric patterns such as the Northern Annular Mode and the Dipole Anomaly. These atmospheric forcings have flushed some thicker multi-year ice out of the Arctic and left thinner first-year ice that is more easily melted out in summer, changed ocean heat transport, and increased recent spring cloud cover that augments the long- wave radiation flux to the surface. Strong evidence for a thinning ice cover comes from an ice-tracking algorithm applied to satellite and buoy data, which suggests that the amount of the oldest and thickest ice within the multi-year pack has declined significantly. The area of the Arctic Ocean covered by predominantly older ice (5 or more years old) decreased by 56% between 1982 and 2007. Within the central Arctic Ocean, the coverage of old ice has declined by 88%, and ice that is at least 9 years old (ice that tends to be sequestered in the Beaufort Gyre) has essentially disappeared. Examination of the distribution of ice of various thicknesses suggests that this loss of older ice translates to a decrease in mean thickness for the Arctic from 2.6 m in March 1987–2.0 m in 2007.
The satellite data record: 1979-present
The most detailed time series representation of sea ice extent is obtained from the UIUC cryosphere web site [link]. While these data are most often interpreted in the context of a linear trend, it is instructive to interpret the record in the context of a (qualitative) change point analysis, defined by changes in trend, mean value, amplitude of the annual cycle, and interannual variability.
- 1979-1988: little trend, consistent interannual variability in the amplitude of the annual cycle.
- 1989-1996: small negative trend (more prominent in the summertime minima), large interannual variability.
- 1997- 2003: lower values relative to the period prior to 1996, with the most noticeable decrease in ice extent being the wintertime maximum; small amplitude and fairly regular annual cycle.
- 2003-2007: marked decrease in wintertime maxima; strong negative trend in both winter max and summer min; continued small amplitude of the annual cycle. A steady decline in wintertime maxima from 2003 to 2007 seems to have led the decline in summertime minima, with a marked decline beginning in 2005 that culminated in the major anomaly of summer 2007.
- 2007-present: return to a large amplitude annual cycle (with an increase in the wintertime max), but with a an overall shift to lower summertime values. The winter 2011 values look anomalously low, possibly with a pattern resembling 2006.
Impact of teleconnection and flow regimes
To what extent can we relate these change points to known climate shifts or changes in teleconnection regimes?
- 1989: shift to strong positive phase of the Arctic Oscillation. This resulted in the transport of multiyear ice out of the Arctic Ocean, setting the stage for reduced ice extent (Rigor et al. 2004)
- 1995/1996: shift to warm phase of the Atlantic Multidecadal Oscillation (AMO); shift to near neutral or negative phase of the Arctic Oscillation
- 2003: vicinity of shift to cool phase of the PDO
The period of strongly positive Arctic Oscillation during 1989-1995 and the loss of multi-year ice set the stage for the large decline in sea ice extent in the past decade.
Possible impacts of the AMO and PDO can be inferred from looking at the longer historical time series of sea ice extent (Fig 2a in Polyak et al.):
- PDO: The 1976 shift to the warm phase of the PDO is evident by a jump to lower wintertime maxima. This would be consistent with the increase in wintertime maxima with the circa 2003 shift to the cool phase of the PDO.
- AMO: The broad cycle of the AMO has some apparent correlation with summertime minima, with high values circa 1880 and 1940’s-1950’s, characterized by the warm phase of the AMO.
There are also several regional studies that examine the impact of teleconnection regimes on regional sea ice variability:
Mahoney, A. R., R. G. Barry, V. Smolyanitsky, and F. Fetterer (2008), Observed sea ice extent in the Russian Arctic, 1933–2006, J. Geophys. Res., 113, C11005, doi:10.1029/2008JC004830. [Link]
We present a time series of sea ice extent in the Russian Arctic based on observational sea ice charts compiled by the Arctic and Antarctic Research Institute (AARI). These charts are perhaps the oldest operational sea ice data in existence and show that sea ice extent in the Russian Arctic has generally decreased since the beginning of the chart series in 1933. This retreat has not been continuous, however. For the Russian Arctic as a whole in summer, there have been two periods of retreat separated by a partial recovery between the mid-1950s and mid-1980s. The AARI charts, combined with air temperature records, suggest that the retreat in recent decades is pan-Arctic and year-round in some regions, whereas the early twentieth century retreat was only observed in summer in the Russian Arctic. The AARI ice charts indicate that a significant transition occurred in the Russian Arctic in the mid-1980s, when its sea ice cover began to retreat along with that of the rest of the Arctic. Summertime sea ice extents derived from the AARI data set agree with those derived from passive microwave, including the Hadley Centre’s global sea ice coverage and sea surface temperature (HadISST) data set. The HadISST results do not indicate the 1980s transition or the partial recovery that took place before it. The AARI charts therefore add significantly to our understanding of the variability of Arctic sea ice over the last 8 decades, and we recommend their inclusion in future historical data sets of Arctic sea ice.
Vinje, Torgny, 2001: Anomalies and Trends of Sea-Ice Extent and Atmospheric Circulation in the Nordic Seas during the Period 1864–1998. J. Climate, 14, 255–267. [Link]
Abstract. The extent of ice in the Nordic Seas measured in April has decreased by 
33% over the past 135 yr. Retrospective comparison indicates that the recent decrease in the ice extent is within the range of variability observed since the eighteenth century. Temporal, monotonically reduced extreme events occur with intervals of 12–14 yr, suggesting that series longer than 30 yr should be considered to obtain statistical significance regarding temporal changes. Otherwise, decadal temperature variation is also found in the northbound warmer ocean currents. The temperature in the upper layers of these currents seems moreover to have increased by the order of 1°C since the cooling during the Little Ice Age. This temperature increase accounts for most of the ice extent reduction since 1860. A strong negative correlation is found between the larger North Atlantic oscillation (NAO) winter index and the Nordic Seas April ice extent, and a corresponding positive correlation is observed for the Newfoundland–Labrador Sea. It is not until the warming of the Arctic, 1905–30, that the NAO winter index shows repeated positive values over a number of sequential years, corresponding to repeated northward fluxes of warmer air over the Nordic Seas during the winter. An analog repetition of southward fluxes of colder air during wintertime occurs during the cooling period in the 1960s. Concurrently, the temperature in the ocean surface layers was lower than normal during the warming event and higher than normal during the cooling event. Northward atmospheric winter fluxes are observed after the enhanced global warming after 1970, and, for the first time over the period considered, a positive correlation is observed between atmospheric and oceanic reducing effects on the ice extent. The enhanced global warming over the past two decades seems also to be manifest in an intensified winter circulation at higher latitudes, rather than a contemporary change in the Arctic Ocean surface temperature.
Liu, J., J. A. Curry, and Y. Hu (2004), Recent Arctic Sea Ice Variability: Connections to the Arctic Oscillation and the ENSO, Geophys. Res. Lett., 31, L09211, doi:10.1029/ 2004GL019858. [Link]
Abstract. Trends in the satellite-derived Arctic sea ice concentrations (1978 – 2002) show pronounced decreases in the Barents/Kara Seas, between the Chukchi and Beaufort Seas, the central Sea of Okhotsk and a portion of the Hudson/Baffin Bay by 2 – 8% per decade, exceeding the 95% confidence level. Qualitatively speaking, positive phases of the Arctic Oscillation (AO) and El Nin ̃o- Southern Oscillation (ENSO) produce similar ice changes in the western Arctic, but opposite ice changes in the eastern Arctic. The manner in which the ice changes are related to the AO and ENSO are demonstrated. Over the last 24 years, the magnitude of the ice changes associated with the positive AO trend and the negative ENSO trend is much smaller than the regional ice trends. Thus, more local or less understood large scale processes should be investigated for explanations.
Role of global warming?
There are many indicators that natural variability has a strong influence on the variability of sea ice extent on decadal to millennial timescales. IMO, the strongest argument for sea ice decline over the last decade for being unusual and at least in part attributable to global warming is this (from Polyakov et al.): The severity of present ice loss can be highlighted by the breakup of ice shelves at the northern coast of Ellesmere Island, which have been stable until recently for at least several thousand years based on geological data.
The overall decline of sea ice with global warming has been predicted by climate model simulations since the past several decades. However, the observed decline does not follow in a simple way the increase in CO2 or variability in global or local Arctic surface air temperatures.
If natural variability is dominant, the sea ice extent could increase if the AO stays predominanly negative, the PDO stays cool, and the AMO switches to the cool phase (a scenario that might occur sometime in the next 2-3 decades).
A complex interplay between natural internal variability and CO2 forcing is the most like explanation. Further research is needed particularly on role of natural internal variability in influencing sea ice thickness and extent.
Almost all the questions I’d wanted to ask about this topic in a skeptical and widely varied discussion setting, collected together in one handy place.
(Btw, Quaternary Science Reviews.)
It’s always been a part of the world deeply mystical and mysterious in my experience, so seeing it through the cold eyes of scientific discourse will be strange for me.
Thanks for the post. I was always interested in comparisons between interglacials and their relative sea levels. I’m to understand that the last interglacial (warm) period had significantly higher sea levels than what we see today. When pressed, the answer always revolved around the forcing due to Milankovitch cycles, but that answer seemed to rely on more arm waving than hard data/calculations. Since I stopped following the academic discussion on this a few decades ago, if there’s a new discussion on this, I’d be very interested.
Mr. Stone:
I have been working on this subject, glacial and warming periods which are integral part of earth science, for over a decade, and there is substantial related mathematics posted on my website http://www.global-heat.net.
Mathematics suggests that there is absolutely no correlation between Milankovitch cycles and past glacial/warming periods. Only the change in the content of carbon dioxide in the atmosphere with time caused theses glacial and warming periods. You may want to start with Article-12, Earth Magic, then go through book PDF posted on the website. You will find that the present warming trend can be scaled-down, or calculated, from the last warming period, a solid proof that carbon dioxide is the common factor between past warming periods and the present global warming. Also, the work calculates approximate sea level during the Last Glacial Maximum and around 125,000 years ago. If you have any questions, please let me know.
CO2 goes up and down with changes in ocean temperature just exactly like the carbonated drinks. Warm Carbonated Drinks have a lot of CO2 vapor and will spew like crazy when opened. Cold Carbonated Drinks have a low CO2 vapor pressure and do not spew nearly as much. The earth’s oceans are giant carbonated drinks and do work exactly the same way. Temperature of the water changes the CO2 and not the other way around.
And at least until recently your ‘complex interplay between natural internal variability and CO2 forcing’ was in fact just a ‘complex interplay among natural internal variabilities’, since CO2 forcing was one of those natural internal variabilities.
So before we demonize anthropogenic CO2 for a new and ‘unnatural’ forcing, how about discovering a little more about the ‘complex interplay of natural internal variabilities?
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I’m not liking what I’m seeing right now in the Arctic. Reasonably good chance we break thru the 2007 low this summer.
possible, or it could be a repeat of 2006
Mid-March is certainly too soon for absolute predictions. We’ll have a much better idea by mid-July.
If I were to put a cyber nickel out right now, we’ll stay below the 2010 extent line thru mid-August at least. The concentrations don’t look so hot, the cold European winter was matched with an above average warm (relatively, of course) Arctic winter. Just not liking the looks of things. Tide and wind certainly play a big role. . .but they play a bigger role when concentrations are low.
‘Analyzing temperature records of the Arctic meteorological stations we find that (a) the Arctic amplification (ratio of the Arctic to global temperature trends) is not a constant but varies in time on a multi-decadal time scale, (b) the Arctic warming from 1910 – 1940 proceeded at a significantly faster rate than the current 1970 – 2008 warming, and (c) the Arctic temperature changes are highly correlated with the Atlantic Multi-decadal Oscillation (AMO) suggesting the Atlantic Ocean thermohaline
circulation is linked to the Arctic temperature variability on a multi-decadal time scale’
http://www.lanl.gov/source/orgs/ees/ees14/pdfs/09Chlylek.pdf
Chylek et al (2009) ad that the ‘observed global mean surface temperature change since 1880 has a combination of causes including increasing
greenhouse gases, variations in tropospheric anthropogenic aerosol optical depth, natural and anthropogenic surface albedo changes, variations of solar radiation, volcanic activity [Hansen et al., 1996; Stott et al., 2000; Pielke et al., 2000; North and Wu, 2001; Mishchenko et al., 2007; Chylek et al., 2007; Pielke et al., 2007; Lean and Rind, 2008], and variability of atmosphere-ocean circulation [Folland et al., 1986; Knight et al., 2006; Baines and Folland, 2007].’
That should about cover it – but I would add solar UV warming ozone in the middle atmosphere and influencing the polar vortices – http://iopscience.iop.org/1748-9326/5/3/034008/fulltext. Although dynamically complex something has to initiate these multidecadal to centennial climate shifts. I am favouring UV unless something with more influence on the polar vortices comes along.
Chylek et al make an interesting comment to the effect that sulphate emissions can’t explain the Arctic temperature change amplification. The sulphate idea is feeble at any rate – especially given recent considerations of black carbon and interactions in the atmosphere. Reducing black carbon is one of the things we should be doing more of – for excellent public health reasons and for reducing snow and ice melt quickly.
Dear Dr. Curry,
Thank you for this post. Equally important is the way arctic ice is presently melting. Precipitation in the arctic has been decreasing, yet river runoffs in the arctic has been increasing, unexplainable observation to this date. Please see this paper: Compatibility analysis of precipitation and runoff trends over the large Siberian watersheds” was published in the Geophysical Research Letters, Vol. 31, L21502, doi:10.1029/2004Gl021277, 2004. Authors of the study are Berezovskaya, Yang, and Kane from the University of Alaska Fairbanks.
If anyone can explain this unusual observation, climate science will be deciphered. Please see Article- 7, global warming in Siberian watersheds, on my website global-heat.net.
Hydrology is at essence simple. The following quotes comes from a gorgeously clear headed overview of 50 year hydrological trends – linked to below. What we are left with are regional changes caused by standing waves in the atmosphere/ocean system – observed as persistent ocean and atmosphere patterns that are at the core of climate change – the NAO, ENSO etc.
‘River runoff (R) can be expressed as the difference between precipitation (P) and the sum of ET, storage (S) (e.g., groundwater), and consumption (C) (e.g., irrigation). Over the long term, ΔR in most rivers is assumed to be driven by ΔP, any significant deviation presumably reflecting ΔET, ΔS or ΔC.
A number of high-latitude and high-altitude rivers experienced increased discharge despite generally declining precipitation. Poorly constrained meteorological and hydrological data do not seem to explain fully these “excess” rivers; changed seasonality in discharge, decreased storage and/or decreased evapotranspiration also may play important roles…
Runoff trends in normal rivers are assumed to reflect primarily the climatic response to oceanic/atmospheric drivers, such as NAO and ENSO (New et al., 2001). Although some normal watersheds are heavily regulated (e.g., N50,000 dams on both the Mississippi and Yangtze watersheds) and some are intensively irrigated (e.g., Don), most normal rivers have low flow regulation indices (total reservoir capacity as percentage of mean annual Q) and low irrigation indices (unitless quotient of irrigated basin area divided by mean annual Q, as defined by Nilsson et al., 2005) (Fig. 7B; data in Table S2). Reservoirs can affect the timing of discharge as well as the amount of discharged sediment and dissolved constituents (Vörösmarty et al., 2000; Meybeck and Vörösmarty, 2004), but for most normal rivers reservoirs appear to have little effect on annual discharge.
By contrast, most deficit rivers have flow regulation and irrigation indices N20 and N200 (Fig. 7B), respectively, underscoring the importance of reservoirs and irrigation (both of which dramatically increased globally between 1951 and 2000) in facilitating water loss by increased consumption and (ultimately) increased ET .’ http://ww2.coastal.edu/kxu/GPC08.pdf
My look into the Arctic produced an unexpected correlation:
http://www.vukcevic.talktalk.net/NFC1.htm
Process involved may not be well understood, but on the other hand when the science rejects everything that is not clear-cut, the progress is slow.
The Changing Arctic
The Arctic ocean is warming up, icebergs are growing scarcer and in some places the seals are finding the water too hot, according to a report to the Commerce Department yesterday from Consul Ifft, at Bergen, Norway.
Reports from fishermen, seal hunters and explorers, he declared, all point to a radical change in climate conditions and hitherto unheard-of temperatures in the Arctic zone. Exploration expeditions report that scarcely any ice has been met with as far north as 81 degrees 29 minutes. Soundings to a depth of 3,100 meters showed the gulf stream still very warm.
Great masses of ice have been replaced by moraines of earth and stones, the report continued, while at many points well known glaciers have entirely disappeared. Very few seals and no white fish are found in the eastern Arctic, while vast shoals of herring and smelts, which have never before ventured so far north, are being encountered in the old seal fishing grounds….
Link-
http://tinyurl.com/4e8rbcx
One factor not often picked up on is that Arctic ice thickness reached a minimum in 2008 (one year after the extent minimum). Since then it has recovered and is now above its average for the first ten years of data.
http://www.climatedata.info/Impacts/Impacts/Impacts/thickness.html
A second factor is that the albedo effect applies not only over the sea but also over land (arboreal forests have a low albedo) but snow and ice cover have fallen only marginally.
http://www.climatedata.info/Impacts/Impacts/snow.html
Since then it has recovered
The reason it hasn’t been “picked up on” is that the analysis is based on pixel counting the images produced by an old version of PIPS. The “skeptic” community that apparently hates models and considers them unreliable is practically tripping over itself to accept the results of a flawed analysis of an old model never intended for that purpose in the first place.
What people are actually waiting for is the Cryosat-2 data which will settle the issue one way or another.
I’m excited about that data too but I think we only get 4 or 5 years of data and then there’s all the fun of calibrating it. I think expecting it to settle the issue is going a step too far but I agree it’ll be a valuable contribution.
First of all I am not a skeptic – if you look carefully at my site you will see that I am that rare animal – a neutral.
Note also that I am careful to use the phrase ‘nominal depth’. I fully recognise that what is represented is an estimate but it is reasonable to assume that the general trend is valid despite the limitation of the approach.
“it is reasonable to assume that the general trend is valid”
No it isn’t reasonable to assume that at all. PIPS is not designed for that purpose and the method of analysis is far from optimal.
The PIOMASS model which actually is designed for this purpose gives the opposite answer to the PIPS analysis
http://psc.apl.washington.edu/wordpress/research/projects/arctic-sea-ice-volume-anomaly/
This may be off-topic, but one thing often overlooked is the growth in Antarctic ice over the same period as the shrinking of arctic ice, with the global total showing virtually no trend. My own thoughts are that we may well see a reversal of this situation in the coming decades, with arctic ice growing and antarctic ice shrinking. If that happens, it will be interesting to see if the focus of the MSM and activist climate scientists shifts to antarctic melting while ignoring artic freezing. I suspect that is exactly what will happen, but time will tell.
“with the global total showing virtually no trend.”
That’s simply not true and can be confirmed even by visual inspection of the global trend.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/global.daily.ice.area.withtrend.jpg
Observe the amount of the time the anomaly stays around zero upto around 2003 and how much it remains below it after that.
It’s simply amazing the number of people who think things that are wrong with even basic research are instead being “overlooked”.
My own thoughts are that we may well see a reversal of this situation in the coming decades, with arctic ice growing and antarctic ice shrinking.
This is wishful thinking based on the “Nothing to see here, natural variability” concept. It could be true but by all means show me the mechanism that regulates the polar ice caps in this way. As per usual in the “skeptic” movement we have a combination of “There’s nothing happening and you can’t prove there is” and “The thing that isn’t happening is explained by natural variability and will surely reverse itself at some point in the future”.
“Observe the amount of the time the anomaly stays around zero upto around 2003 and how much it remains below it after that.”
Huh. Perhaps if I make comments about 30 years as the minimum in climate studies, you might think about retracting this comment or at the very least cease complaining that “deniers” need to get their heads around the concept (if you make such complaints), or at the very least, deride anyone who uses <30 year trends as "proof" of anything in climate.
“It’s simply amazing the number of people who think things that are wrong with even basic research are instead being “overlooked”. “
I did not mean to imply that scientists did not know of this or were wrong, but rather was pointing out that it seems to me that the advocate community seems to pick and choose when “global” is important and when “regional” is important. Much like your arguement above about trends in arctic ice since 2003, how much traction would I get suggesting that surface temperature trends in some region the size of the arctic showed a negative trend? Would I not be told that “global” matters? Surely the same is true of all indicators such as ice cover, cloud cover, precipitation etc? Sure, it does matter to people where these things happen, but if I need to consider only global temp, why not global ice coverage?
“This is wishful thinking based on the “Nothing to see here, natural variability” concept. It could be true but by all means show me the mechanism that regulates the polar ice caps in this way. “
Have we already change the null hypothesis from “it’s all natural until you can show otherwise” to “it’s anthropogenic until you can show otherwise” while I wasn’t looking? If you can’t demonstrate that it’s unusual, why do I need to prove it’s natural? If there is evidence of climate “cycles” (IOW, semi-cyclic, stochastic driven oscillations in weather patterns) on the scale of 60 years, 180 years etc etc – and I believe it’s fair to say there is – under what conditions can you expect to be able to extract something “unusual” in the 30 year record of sat coverage?
You seem to be of the opinion that I think “climate scientists” are idiots – for the record, I do not. I merely think that in many cases, they go a bridge to far based on what is known and what is infered. And if history in general, and science history in particular, is any guide then I want something a bit more concrete than what I have seen so far before I’m prepared to commit to the sorts of actions being contemplated, and in some cases enacted, to deal with the “problem”. You may acuse me of ignorance if you wish and I most certainly will not suggest that I am any sort of expert on matters climate, but I believe it’s fair to say that I am a level 3 on Judy’s scale (having followed this with varying zeal over about 15 years), so I am not completely ignorant on the matter. Just not convinced the level of certainty is justified, or that the urgency suggested is justified. Feel free to attempt to convince me.
“Huh. Perhaps if I make comments about 30 years as the minimum in climate studies, you might think about retracting this comment “
The 30 year norm defines the current climate state, it’s not a magic at line upto which everything observed is ignored. The Arctic ice has been “odd” for at least a decade which makes it a subject of serious study. Changes which come and go for a year or even a few years are interesting but not of note but changes which stay put are.
“Much like your arguement above about trends in arctic ice since 2003, how much traction would I get suggesting that surface temperature trends in some region the size of the arctic showed a negative trend? “
You’re the one who made the claim that it was being “overlooked” there was no change in the global trend. The obvious and negative change in the global trend was pointed out to you and now you’re crying foul with irrelevancies.
With regard to regional and global the issue is the what the preponderance of data shows and the likelihood of what future data will show. If you take three major regions of note (Arctic, Antarctic, Greenland) and 2 of the 3 are showing major decline that’s an important caveat regardless of how much region 3 compensates for the other 2.
The actual issue here and always is what is happening in the real world not what technicality can be invoked to ignore what is happening in the real world. Nobody even vaguely interested in the issue of glaciers or sea ice could say with a straight face it’s business as usual. The people who do say that are the same who would never accept anything as being odd, even when the ice caps melt it’ll be “Well if you just go back a few millions years….”
” before I’m prepared to commit to the sorts of actions being contemplated,”
Policy is completely and utterly irrelevant to what’s happening in the Arctic. You want to define reality in relation to your policy preferences such that you’ll only accept conclusions concerning Arctic ice at the same time as you’re prepared to accept whatever policies you think people are proposing if it were true.
The real world doesn’t care about your police preferences. It’s doing what it’s doing regardless of who you elect to Congress and whatever you read on blogs about the reds coming to steal your taxes.
“Just not convinced the level of certainty is justified”
You were and are pretty certain that nothing is happening. Your defence of this position spent a lot of time discussing your opinion of climate science and your policy preferences but very little time on the details of the topic you’re addressing. That strongly suggests your viewpoint is political or idealogical in nature and consequently you’re using the wrong information to form opinions on unrelated topics.
“The 30 year norm defines the current climate state, it’s not a magic at line upto which everything observed is ignored. The Arctic ice has been “odd” for at least a decade which makes it a subject of serious study. “
So a decade of no, or well below projected, increases in global average temperature would be “odd” and a “subject of serious study” then, would it not? Apparently it is not – it’s just “weather” according to RC and many others. I trust the point is now clear – you cannot dismiss people because of a “rule” you invent, then throw that rule out when it suits you. I don’t know what sort of logical fallacy that is called, but it is very annoying.
“You’re the one who made the claim that it was being “overlooked” there was no change in the global trend. The obvious and negative change in the global trend was pointed out to you and now you’re crying foul with irrelevancies. “
As I said, it appears to me that such is very much “overlooked” by those who wish to promote their agenda (whatever that may be). I fail to see how pointing out what I consider to be inconsistencies in the arguments of the “faithful” is irrelevant.
“The real world doesn’t care about your police [I assume that’s meant to be policy] preferences. It’s doing what it’s doing regardless of who you elect to Congress and whatever you read on blogs about the reds coming to steal your taxes. “ I am not in the least concerned with “reds coming to steal my taxes”, but rather more concerned with people making claims that the data does not appear to support to anywhere near the level their “expert opinion” suggests, and using those claims to push policy changes that affect billions of people. And even more worried that if they continue down this path, it is the reputation of science, not my hip pocket, that will suffer the most – not because they are “wrong”, but because they are “wrong enough”; that many will see any future predictions – regardless of how certain the author of such predictions may rightfully be – as just more rubbish; that we may miss the chance to make changes we really need to because you’ll be dismissed as “those crackpots that said they knew what the weather was gonna be in 20 years time are at it again”.
“You were and are pretty certain that nothing is happening. “ I did not say that – I said that I do not believe that the level of certainty reported is justified by the data that currently exists. There is plenty of data for the last 30 odd years thanks to satellites. There is a significantly less before that, and what does exist is perhaps best described as “patchy, sketchy and very incomplete”. To therefore suggest that what we have seen in detail is “unquestionably unprecedented” is going a bridge too far – actually several bridges too far, IMO, but one will do for now.
You certainly seem very aggressive in your defense, but perhaps that’s just me. I don’t comment here often and I certainly try not to be argumentative just for the sake of it, or to support any political views I may have. I am happy for people to correct me if I’m wrong. Jumping down my throat because I point out what many lay people would consider an inconsistency in the argument is not productive – explain to me where and why I’m wrong, and – it may surprise you to learn – if your case is convincing, you will have won a supporter.
The first thing that caught my eye was ” Arctic sea-ice extent and volume are declining rapidly.” I wonder what Polyak et al, base this statement on.
Measuring sea-ice volume has always been difficult, and I am not convinced that volume is “declining rapidly”. We have the new satellite (Cryostat2 ?)now actually measuring sea ice volume, but I have not, as yet, seen much data from this. I would like to see a lot more data before I can accept that sea-ice volume in the Arctic is, in fact, “declining rapidly”.
“(Polyakov et al.): The severity of present ice loss can be highlighted by the breakup of ice shelves at the northern coast of Ellesmere Island, which have been stable until recently for at least several thousand years based on geological data.”
The “stability” of something is only indicative of past performance. The current interglacial has been having a cumulative effect on the planet for over 12K years. Ice melts. The cooincidence of manmade CO2 and “X”, “Y”, or “Z” must be proved. It cannot be inferred or assumed via cooincidence.
We are searching. We have not found the answer(s) to our question(s). Fortunately, real scientists are working to find real answers and are not in league with a bunch of moneygrubbing politicians, anarchists, and psyentists, only bent on turning civilization on its head and frightening the children of the world with a coming DAY OF DOOM (while making a little $$$$$ in the process).
“cooincidence” and any other type-o’s are only a coincidence
Klyashtorin and Lyubushin report on the cyclical sea ice coverage of the Barents Sea and the Sea of Okhotsk, from page 45.
http://alexeylyubushin.narod.ru/Climate_Changes_and_Fish_Productivity.pdf?
They find a cycle of about 60 years, with a lag of about 8 years following changes in global temperatures.
Thank you. That was what we sceptics were saying forever.
Let the observation be our judge before committing the world from wasting valuable resources on a non-problem.
The conclusion of the Polyak et al Abstract sounds disturbingly like the standard AGW alarmist logic, to wit: “This ice loss appears to be unmatched over at least the last few thousand years and unexplainable by any of the known natural variabilities.”
In reality we do not know what past ice conditions have been on the 30 year scale in question. “High resolution proxy data” is an oxymoron, as proxy data is inaccurate by hypothesis. Moreover, we well know that we do not know the important natural variabilities.
David, the one argument that is convincing on these time scales is the breakup of the CAA ice shelves (off the Canadian Archipelago) that have been there several thousand years.
“Convincing” of what Dr. Curry? A single local event like this tells us nothing about the overall behavior of Arctic ice over the last few thousand years. It certainly does not tell us that the Arctic has never been this low on ice in the last several thousand years. As I understand it there is evidence that it may have been this low in the 1930’s. But we really don’t know.
It doesn’t even tell us much about local CAA conditions over the last few thousand years, until we know why it happened. It is barely suggestive, much less convincing. This is the real problem, namely people being convinced by the weakest possible evidence.
This is the real problem, namely people being convinced by the weakest possible evidence.
As I understand it there is evidence that it may have been this low in the 1930′s
Mmm yes indeed.
Tell me is there any way to separate the claim “But we really don’t know.” from “David Wojick doesn’t know” or “David Wojick doesn’t want to know”? You see it’s one thing to claim that something is known and to provide evidence of such but to claim something is not known requires a degree of confidence that individual is sufficiently expert to be aware of everything that is known on the topic in question.
I see all sorts of things argued as “not known” in the climate debate, from current global temperatures to atmospheric physics and historical conditions. It’s simply argument by ignorance whereby the arguer gets to simultaneously define the state and the conditions by which the state may be considered to have changed “Oh this is not known. What all the evidence that says it is? Oh none of that evidence is good enough, it’s not known”.
while surface land temps were warm in the arctic during the 1930’s, comprehensive analyses of available data do not show any big summer melt back, although there were occasional anecdotal reports that appeared in the media where a particular location was surprisingly ice free. I would like to see more attention paid to the historical record prior to 1950’s, to see if there is any additional info that can be gleaned
We don’t know what the Arctic surface land temps were in the 1930’s, not that it matters. I just mentioned the 1930’s as an example anyway. How about 900AD? What was the ice extent in 903AD?
More generally, I think that phrases like “comprehensive analyses of available data” are misleading at best. Comprehensive analyses of inaccurate data do not make it more accurate, so there is a false suggestion of certainty. “Comprehensive analyses of inaccurate, unrepresentative data” might be better.
Moreover, if we are talking about proxy data then that is not even real data. That is, it is not actual measures of the parameter in question. One might call it “hypothetical data” as the relation between it and the parameter we are trying to measure is a matter of hypothesis. Sediments and whale bones are not ice, just as tree rings are not temperatures. Here the phrase “comprehensive analyses of hypothetical data” might work.
A lot of climate science would read very differently if these more accurate locutions were used.
Re arctic coastal surface land temps in the 30’s, see this article. There were quite a few observations. Note the surface land temperatures in the Arctic were quite warm during the 1930’s. But as I argued in my post, there is not a direct relationship between arctic surface temperatures and sea ice extent.
http://journals.ametsoc.org/doi/pdf/10.1175/1520-0442%282003%29016%3C2067%3AVATOAT%3E2.0.CO%3B2
There is a fair amount of data for the North Atlantic sector for the 1930’s e. g. here:
http://acsys.npolar.no/ahica/intro.htm
In general it seems that in most summers there was as little ice in the 1930’s as in the 2000’s but that in winter there was usually more ice in the area north of Iceland and around Jan Mayen than there has been in recent years.
Further east in the White Sea – Barents Sea area conditions in the 1930’s and recent years have apparently been very similar both in winter and summer.
Judith,
What’s the best sources of ice data for the 1930’s? I’ve been curious about how the ice looked in the 1930’s but have failed to find any good data. I even wrote to the Canadian Ice Service who have no ice data before 1968. 1930’s arctic temperature data doesn’t seem so far from the present phase but reconstructions that exist have the ice conditions very different.
David read the whole Polyak et al paper, beyond the abstract which presents their conclusions. The one period that might be interesting to look at in terms of an analogy is mid 19th century, tonyb has some info about this I think. But there is no evidence of any kind of a widespread meltback in the 1930’s (and there is fairly substantial evidence to the contrary).
On the contrary I would suggest that there is considerable evidence for widespread meltback north of Siberia in the 1930’s.
In 1932 the Knipovich, a 100 ton wooden vessel circumnavigated the Frans Joseph archipelago while in the same year Sibiryakov sailed around Severnaya Zemlya, something I don’t think has ever been repeated except by nuclear icebreakers.
And two years later Sadko reached 82 deg 42 min north in ice-free water west of Severnaya Zemlya.
Of course there were also difficult ice years in the 30’s, particularly 1937 when several ships got stuck in the northeast passage and had to winter.
When it comes to past states of regions( including the whole globe), for which we did not have designed observing systems at the time, it is relatively easy to know what we do not know. This is because we know how to design sensing systems to meet given standards of accuracy. Statistical sampling theory and measure theory play a major role in this kind of design.
So for a parameter in question, such as total arctic ice volume in 900 AD (or global average temperature in 1932), one first asks what system would be necessary to provide the needed accuracy? Then if we do not have that system, we can probably safely conclude that we do not know the value in question.
I happen to have studied both these cases. In fact several people have argued in this thread that we do not know today’s arctic ice volume, much less what it was in 900 AD. So it is not just me that does not know, it is all of science. If you do not have the observing system then you do not have the observational data. You can guess and you can speculate but you can’t know.
The basic point is that error and uncertainty are sciences of their own. These sciences are mostly applied in engineering, where we have to know what we do and do not know, but they are little applied in climate science. Unfortunately climate science is driven by taking weak proxy data, which is all we have, and drawing conclusions that are completely unrealistic in their certainty. I call this the fallacy of false certainty, and it is the central logical feature of climate science today, because that science is in the grip of advocacy. False certainty is the hallmark of advocacy.
David Wojick
I’m told by those who know this better than I do myself from the historical record, from archeology, from linguistics and from the evidence of genetics, that wave after wave opportunistically and aggressively migrated from the northern reaches of Europe over the past millennia.
They made it as far as India and the Horn of Africa, into the lands for a time called the Holy Roman Empire, through the Steppes and on and on, establishing colonies and empires, to the extent of the reach of first their riders and then their longships.
While they invariably withdrew eventually, they left their mark everywhere they went in the Old World.
Were the Arctic so recurringly porous a passage that by as late as 900 AD it was as passable as it is today, then one might expect more than just the scant and limited reports and traces of European presence in the New World that we have today.
Further, there are studies of how the Inuit and the Saame are related, which would be testament to Arctic passability. The history and geography of human genes, (Luigi Luca Cavalli-Sforza, Paolo Menozzi, Alberto Piazza) p. 229 suggests that only the Bering passage was ever employed by indigenous populations to transit the circle, casting extreme doubt on an Arctic as ice-free in the distant past as it now is.
So really, while ‘we do not know’ is correct with regard to past Arctic ice-free episodes, suspecting such is more than simply baseless, but also contrarian.
The Inuit history, such as it is, would seem to indicate variability is significant at decadel and centenial time scales. Perhaps there is much evidence here too.
Neil Fisher
Could you cite a source for this report?
Was it something along the lines of the documentary http://www.cbc.ca/documentaries/natureofthings/2009/inuitodyssey/director.html that describes a circumpolar Thule conquest across the Bering strait at the start of the MWP?
Dr. David Suzuki has reported repeatedly in interviews with Inuit elders that they have never seen anything of the like of the current situation, which of course would cover their own lifetimes and a few generations of oral tradition at most.
There are international disputes (http://www.ciel.org/Climate/IACHR_Inuit_5Mar07.html) based on these Inuit claims.
Given the nature of eyewitness testimony about weather conditions from people (especially after six or more decades), and of the oral tradition (and the various written records made since European contact) even of the highly weather-sensitive circumpolar peoples, we’re likely to always have room for some skepticism.
It seems there are on the millennial scale sometimes events of great impact on the Arctic, but decadal and centennial appears probably overstated.
He’s right you know Dr Curry- until you can attribute a definitive cause to their break-up, you don’t know what they tell you either way- lest we have another kilimanjaro here.
One could just as easily say that as they haven’t broke up for several thousand years that they were DUE a break.
Without causation it’s just arm waving.
There are two ways for the breakup to occur: thermodynamic (melting) or dynamic (ocean/wind driven). The latter could occur only if there is alot of open water; otherwise the dynamics will act to pile up the ice even further in the region.
I’m confused- i still don’t see how either of these lend credance to the cAGW theory. They could still both be entirely natural.
Am i missing something? Or is it just that these sheets were supposed to be stable so that any change is alarming? Seems a weak premise (if that indeed IS the premise).
See pascvaks at 7:51AM
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Dr. Curry,
Disturbing to see this kind of reasoning from you. Jumping to conclusions is never pretty.
The complexity of the system renders absurd dependence on such a simplistic conclusion. The plank you feel you’ve grasped is probably a weak reed.
==============
My conclusion comes from many simulations of Arctic sea ice that my research group has conducted over the years. The ice that is most difficult to melt (it is very thick and land fast) is the ice to the east of the Canadian Archipelago. This ice has now broken up (ice which was previously there apparently for several thousand years). I stand by my statement that this is the strongest argument IMO for something exceptional to have happened to the sea ice on millennial time scales
Ice melts from local conditions. Extrapolating from local to global is problematic.
=============
There was big time vulcanism at the Gakkel Ridge in 1999. Is that local enough? I realize I’m being highly speculative here.
============
And we all know about climate scientist s and their computer models.
Baa humbug!
Dr. Curry,
Your belief that the current melting of Arctic sea ice may at least in part be attributable to AGW, if I understand correctly, is based on: “many simulations of Arctic sea ice that [your] research group has conducted over the years,” proxies like those in the paper that is the subject of the post, and “the breakup of the CAA ice shelves” (a current localized phenomenon).
I wonder if you can quantify what you mean by “at least in part” in your assertion that melting Arctic ice can be attributed to AGW. Is there a range? And what is your level of certainty in this area?
It seems that, in the area with which you are most familiar, computer models, proxies and evidence of an individual current event are not so uncertain as to make you hesitate in making such a judgment on attribution. Yet you seem less sanguine about the attribution claims made by those using other models, proxies and events, in other areas of climate science.
Aren’t the known unknowns, and unknown unknowns that cause you to question the certainty of the consensus over all, sufficient to create similar uncertainty in your area of expertise?
Gary, it is easy to say that AGW must be having at least some effect on arctic sea ice. Some is an ambiguous word, admittedly, but I think it is indefensible to say with any certainty that there is NO effect of AGW on the arctic sea ice. By the same token, it is insupportable to state that the recent melt back is 100% caused by AGW. Both are factors. Until we have a better understanding of the decadal modes of natural variability and can model them, it will be difficult to sort this out with any level of confidence.
Did this breakup suddenly happen? Or has it been weakening for say the last few hundred years since the LIA?
“the one argument that is convincing on these time scales is the breakup of the CAA ice shelves (off the Canadian Archipelago) that have been there several thousand years”
Doesn’t this assume that climate is in equilibrium and free of intertia, oscillation or external influence on time scales longer than the event you are studying? For example, if the CAA ice shelves have only existed for several thousand years, then that would mean that they have broken up previously in the current interglacial, and there is nothing very special about their current break-up. It has happened before, it will happen again. What would be unusual is if it did not break up, after having broken up previously.
The CAA ice shelf was already breaking up when it was discovered by the Nares expedition in the 1870’s. This is clear from their descriptions and images of “floebergs” which were obviously detached sections of shelf-ice.
The main period of breakup was apparently in the 1930’s or early 1940’s to judge from T3 and the other “ice-islands” discovered after WWII.
I have picked some sentences from this post and added my own thoughts. And some good links.
I read: Retrospective comparison indicates that the recent decrease in the ice extent is within the range of variability observed since the eighteenth century.
I write: The temperature and sea ice extent is well within the range of variability of the past ten thousand years of extremely stable temperatures.
I read: This temperature increase accounts for most of the ice extent reduction since 1860.
I write: That is backwards! The ice extent reduction accounts for the temperature increase. Include albedo in your models and theories as a driver and not as a driven.
I read: Concurrently, the temperature in the ocean surface layers was lower than normal during the warming event and higher than normal during the cooling event.
I write: Warm Ocean and Low Sea Ice Events lead to more snow and higher Albedo and Cooling. Cold Ocean and High Sea Ice Events lead to less snow and lower Albedo and Warming.
http://www.nsf.gov/news/special_reports/autumnwinter/model.jsp
http://docs.lib.noaa.gov/rescue/mwr/050/mwr-050-11-0589a.pdf
http://www.click2houston.com/video/27156168/index.html
One theme that runs through all of this (very interesting) commentary is that ocean temperatures in the Arctic are higher than normal: “Soundings to a depth of 3,100 meters showed the gulf stream still very warm.”
As a kitchen table scientist, I have a question that begs for quantitative clarification. I think it was in third grade that we learned that 4/5 of ice (cube or berg) in water is below the surface. Then, (was it 7th grade?) we learned that ice melts much faster in water than air of the same temperature. This has been empirically demonstrated at any number of summer BBQs and close observation of ice sculptures that survive for hours at room temp, but melt away instantly with a dousing of room temperature water.
So it seems obvious that a) only 1/5 of the ice is even exposed to the air for possible melting by higher air temps, and b) warmer water is going to have a vastly greater effect on melting than anything that happens in the air. What I am interested in is a quantitative discussion of the differential effects, because from my kitchen table (9 degrees north in Panama), it looks like increased melting of Arctic sea ice due to a small incremental increase in air temperature due to AGW would be lost in the noise of what happens below the waves with changes in oceanic circulation.
increase in air temperature due to AGW
Why do you think AGW only effects air temperatures?
Did you follow the link and see that the Warm Arctic Story was from 1922?
Warm water does melt Arctic Ice and that warms the Arctic Air.
You are right on!
That causes more snow which, at some point cools us again, as it did this winter
Hi Orkneygal and Alexander,
Also note that the 1922 story expresses concern that one can navigate as far North as 81N – in September/October.
You can navigate that far North today – in March. You could check this on the Cryosphere Today or the University Of Bremen websites.
For the second time, Orkneygal, as I note that you have placed exactly the same story on Climate Progress earlier today, it does tend to be warmer in the Summer than in the Winter.
Which part don’t you understand? Or are you not programmed to understand?
Posts over at Climate Non-Progress do tend to get “lost”, haven’t you noticed.
In any case, what do you feel is wrong with posting a relevant commentary on different blogs, exactly?
Especially when the commentary is not so much about ice extent , but rather illustrative of the nature and history of alarmism.
Hi everybody,
According to the latest estimates, around 90% of accumulated Anthropogenic Global Warming is stored within the the oceans. Water has 1,000 times the thermal capacity of air.
Over the last few decades, the most significant and growing Sea Surface Temperature (SST) anomaly throughout the world has been in the North Atlantic – every area of the perennially ice free Ocean North of a line drawn between Newfoundland and Southern Scandinavia.
The seawater entering the Arctic through the Fram Strait – a volume of water 8 times greater than all of the freshwater entering the ocean via all of the world’s river systems combined – is now the hottest that it has been in at least 2,000 years.
Note that the Pacific has little influence on the Arctic. The Bering Strait is too shallow and too narrow.
The Arctic is melting because 1. the water arriving there is incresingly warm and 2. this means there is more surface open water, so the albedo is less.
I think, Dr Judith, that there are many more signs that we are in unprecedented territory than just the break-up of the Ellesmere shelf. I was reading just yesterday about the voyage of the USS Nautilus in 1958, which had to turn back because ice with a draft of 18 metres was blocking the Bering Strait.
Unless the PIOMAS figures are fiction and the TOPAZ figures are fiction, the Arctic will be seasonally ice-free by about 2014 +/- 3 years. The recent volume trend is that severe.
Of course, this is not catastrophic.
What is catastrophic is what inevitably happens next. When you take the ice from a glass of soda, the soda goes flat a lot quicker. In the Arctic, when you remove the layer of floating sea ice, the next thing to start warming will be the sea bed.
The sea bed is also frozen, and is composed of methane clathrates. When one litre of surface solid sea ice melts it forms one litre of liquid sea water. Remove the ice and the same amount of heat would raise the temperature of 80 litres of water by one degree.
At the seabed, with the clathrates, the sum is a bit different. It takes less heat to melt them, and when you melt one litre of methane clathrate, you get only 0.8 litres of seawater – and 168 litres of methane.
As the melt of surface sea ice is measured in thousands of cubic kilometres, not litres, this might be a better unit for measuring this methane. Then don’t forget to add 6 times the quantity of air to form the “perfect” mix.
Over the next few years, with the AMO cresting, with the Solar cycle resuming and with the most ignorant antediluvian bone-headed morons in living memory having just taken over the legislature of the most powerful country on Earth, this could all get terribly exciting.
Idunno,
I’m assuming your prediction of future events is directly linked to man-made CO2? That if man were not releasing CO2 into the atmosphere, then your predictions would not come to pass? If so, would you be willing to state that if your predictions are not observed, then AGW is a false hypothesis? Or would you just tweak your hypothesis to keep it alive? Part of the frustration skeptics have with proponentss of AGW is that they tend to never state that “if ‘X’ is not observed, then AGW does not exist”.
Hi Jim S,
I think that there are probably 3 significant factors in the current perilous state of the Arctic Sea Ice:
1. The Atlantic Meriodonal Oscillation is currently reaching a crest. Which is largely natural, but is perhaps amplified by AGW.
2. Atmospheric CO2 has risen significantly over the last 200 years. The level of methane CH4 has risen proportionally even higher. Both are significant greenhouse gases.
3. Solar activity, which has been at a level comparable to the Maunder Minimum during 2008/9, is showing signs of reviving. This has nothing to do with AGW.
Of these, listed above in my personal order of significance, only the second shows an inexorable rising trend.
I have been taking special interest in the Arctic recently, and I will be quite surprised if the surface sea ice survives the current crest of the AMO. But it might…
If it does, then we will perhaps be spared any accidental atmospheric testing of the clathrate gun hypothesis for the next 60 years or so, until the AMO peaks again.
So the only things to worry about due to increasing levels of CO2 in the atmosphere and associated AGW would be:
ocean acidification, coral bleaching, desertification, rainforest dessication, increasing atmospheric water vapour and associated extreme precipitation events, changing climatic zones, food security issues, sea level rise, whatever…
So, no, I can see I’m perhaps being frustrating, but I don’t think that the argument is entirely over if the Arctic sea ice doesn’t disappear in the next few years. I personally think it will, but “The sea is deep, and who shall fathom her?”
All sorts of surprises could be in store. And knowledge never ceases to advance – just in the last month we have that Antartica is forming ice from below, at a depth of 2 km. Arctic plankton generate a kind of natural anti-freeze. Who knew?
A more considered view of what may occur this year at least can be found at:
http://www.science20.com/chatter_box/arctic_ice_march_2011_update_1-76988
In the meantime, there are a couple of tens of thousands of scientific studies in from all over the planet that seem to have convinced assorted pinkoes like myself, the US Navy (never the same after the Village People) and the USAF (in its guise as NASA), the UN and all reputable scientific bodies worldwide that CO2 is in fact a greenhouse gas.
I doubt if the rest of them will change their minds if my personal prediction turns out to be wrong.
Idunno,
–ocean acidification, coral bleaching, desertification, rainforest dessication, increasing atmospheric water vapour and associated extreme precipitation events, changing climatic zones, food security issues, sea level rise, whatever…–
What event can’t be attributed to AGW? That’s what I’m interested in. What exactly would you need to observe (or not observe) to reach the conclusion that AGW is NOT happening? You’ve made a list of almost every conceivable thing that can happen, but have yet to provide a description of what the climate would be like if AGW is not happening.
Jim – Let me take a stab at answering your question. It is possible to measure the infrared radiance in CO2-band wavelengths via satellite from space, and at ground level for downwelling infrared radiation. If further CO2 increases do not further reduce the escape of energy to space in the wings of the CO2 band centered at 15 um, broadening the “ditch” (see below), and if elevated temperatures do not increase the downwelling IR in the relevant wavelengths, we can conclude that capacity of atmospheric CO2 to significantly alter atmospheric energy balance is inconsequential, and warming attributable to CO2 must also be inconsequential. Conversely, if the expected reductions in infrared escape and increases in energy redirected downward are observed, we must conclude that CO2 is operating as generally described. Ascertaining the exact magnitude of the effect will still require additional data, but the effect cannot be trivial.
For examples of how increased CO2 will carve further widths out of the “energy ditch”, see David Archer’s model at Modtran CO2 Simulator.
How likely are the simulated results to match observed radiance measurements in the future when the appropriate variables are entered, including changes in the greenhouse warming due to water vapor? Allowing for only minor deviations between simulation and observation, I expect the probability to exceed 99 percent, so it’s a good test of one aspect of anthropogenic climate change. The simulator does not itself predict changes in water vapor or clouds, and so those feedback variables are a separate source of data with a higher uncertainty, but still likely to change in a manner that does not radically alter the results expected on the basis of current understanding. Rather, they will affect magnitude.
Regarding one other item you mention, ocean acidification is a potentially serious consequence of increasing CO2 concentrations, but it is not the result of warming. Rather, it reflects the fact that Co2, on dissolving in water, adds to the hydrogen ion concentration of the water.
There are many other secondary consequences of warming mediated by anthropogenic greenhouse gas emissions (e.g., a reduction in the diurnal temperature gradients), but the radiative mechanisms I cited are a good start. This is probably as extensive as one can get within a single comment, because the topic is almost inexhaustible.
Fred,
Thanks for your thoughtfull reply. However, my question was largely Socratic in nature. I was responding to Idunno’s list (not mine) of “possible” observations in an attempt to illustrate Popper’s point that a propositional statement that attempts to explain everything , in fact, explains nothing. Thus, when one is told that global warming will both increase and decrease snow fall and both increase and decrease precipitationn, etc. it’s a good indicator that the propositionall statement has been framed incorrectly. If you put forth a propositoin you must also define under what conditions it can be shown to be false.
Idunno- t seems that you jump to conclusions without supporting data or you seem to ignore data and common sense.
You wrote- “current perilous state of the Arctic Sea Ice” – (What is perilous about the current state??)
You wrote- “The Atlantic Meriodonal Oscillation is currently reaching a crest. Which is largely natural, but is perhaps amplified by AGW.” – (Isn’t it also true that perhaps it is being minimized by AGW—you have no data to support your conclusion)
You wrote- “I will be quite surprised if the surface sea ice survives the current crest of the AMO.” — (The fact is that arctic ice is currently no less than 2006/2007 although CO2 levels are higher.)
You wrote about your other concerns about AGW- (my comments by each)
1. ocean acidification- (the new AGW believers standard—there is no evidence of a problem….just a buzzword….and there is evidence of it being a non issue)
2. coral bleaching ( there is considerable evidence that corals grow fine in warmer waters as they did for thousands of years
3. desertification (this one is pretty silly since it is predicted that there will be more global rainfall- In areas where the actually get less rain perhaps they could build water storages systems (we can call them dams and reservoirs). The increased numbers of humans over the next 50 years is a larger worry to the water supply that CO2 growth)
4. rainforest dessication (see number 3)
5. increasing atmospheric water vapour (and this is a problem why?)
6. extreme precipitation events (perhaps countries might actually construct infrastructure….call it sewer systems….to properly drain rainfall to where humans want to store water for future use)
7. changing climatic zones (How is this a problem? Do you assume that the climate would be stable except for CO2….it never has been.)
8. food security issues ( there is absolutely zero reason to believe that AGW would mean that the world’s food supply will be lower. With infrastructure properly constructed quite the opposite is true)
9. sea level rise (over the time frames involved this is another silly issue. On a long term scale; 500 M years, we are currently near to the all time sea level low levels. It is unreasonable to assume that sea levels will not rise over time regardless of AGW. Even with AGW the rate of any sea level rise, over the time scale that it will happen will allow for protection to be build by the locally affected areas. It is just not that difficult to build a sea wall over the course of decades.
Jim S,
“Or would you just tweak your hypothesis to keep it alive?’
The comment above mine is just a very long “yes.”
You can ask again if it doesn’t happen in 60 years. Not that that would disprove CAGW either. But it might mean the time line would have to be “tweaked” again. Once so many people invest so much of their ego in a premise, you can forget about objective analysis.
One of those “most ignorant antediluvian bone-headed morons in living memory” conservatives, William F. Buckley, had a term for this mindset – “invincible ignorance.”
But at least we are talking about “science” here.
90% is stored in the oceans, you claim, yet the heat is missing.
Are you referring to the boneheads that subsidize windmills?
Or the boneheads who killed off the nuclear power industry?
Or possibly the boneheads who thought Kyoto would make any difference at all in the climate?
Just wondering.
Please explain the physics as to how IR from CO2 in the air heats the water : “…90% of accumulated Anthropogenic Global Warming is stored within the the oceans.”
I wish to be educated.
What a fine piece of alarmism! I particularly like “…the Arctic will be seasonally ice-free by about 2014 +/- 3 years.” A testable hypothesis that includes this year. Unfortunately you kind of spoil it at the end by including “…with the most ignorant antediluvian bone-headed morons in living memory having just taken over the legislature of the most powerful country on Earth…” as it suggests a political bias. Just a thought.
David Wojick
I’m not all that familiar with Chinese politics. Could you expand on that?
lol….you should be directing you question to idunno since he is the one who made the statement
Rob Starkey
If you dunno, how can I ask the one who made the statement?
Hi David,
Thanks for the compliment. I am more alarmed than alarmist though.
I include this year because I think it highly possible that the Arctic will be ice free this year. There is no longer any substantial body of thick ice in the Arctic, as can be seen on:
http://topaz.nersc.no/
You need to click through to the following page and enter the variable “hice” in the Arctic maps. Unfortunately, they have not updated since 24 February, but a comparison of that date this year, in 2010 and 2009 will show you what I mean.
If you would like to read the science behind the more alarmed sections of my post, try Googling the “clathrate gun hypothesis”. That should quickly get you to NASA’s take on it. This has been a global research priority for several years.
My political bias is quite genuine; and I have taken no pains to hide it. I feel it is better so.
You know i would like to hear Gavin’s thought’s on this one you there Gav ?
I alway’s like the sea will raise after the floating ice melt’s epic fail!!!
ATTN: Prof Curry
RE: Climate Cycles
RE: What the Russians Say
The English translation of “Cyclic Climate Changes and Fish Productivity by L.B. Klyashtorin and A.A. Lyubushin can be downloaded for free thru this link:
http://alexeylyubushin.narod.ru/Climate_Changes__and_Fish_Productivity.pdf?
NB: This mongraph is 224 pages and is not about climate science. The Russian edition was published in 2005. The English translation was published in 2007 and was edited by Gary D. Sharp, Center for Climate/Ocean Resources Study. See: http://sharpgary.org/
By analyzing numerous time series of natural phenomena influenced by climate, they found that the earth has several global climate cycles with periodicities of 50-70 years and that the average of these cycles is about
60 years which has a cool and warm phase of 30 years.
The last warm phase began in ca 1970-75 and ended in ca 2000. The global warming from ca 1975 is due in part to this warm phase. A cool phase started in 2000 and their stochastic model predicts that it will last until 2030.
In particular, you should read pp. 51-54 and study Table 2 (p. 53) , Fig. 2.22 (p. 52) and Fig. 2.23 (p. 54). Here they show and discuss the influence of world fuel consumption on and its relationship to recent global temperature fluctuations. They show show that rising world fuel consumption does not change the periodicity of the 60 year climate cycle.
You should also check:
“Climate Change and Long-term Fluctuations of Commercial Catches: The Possibility of Forecasting” by L.B. Klyashtorin
FAO Fisheries Technical Report No. 410. Rome FAO. 2001. 86pp.
This paper is the forerunner to the mongraph.
FYI: Kevin T presented seminar on climate change a few weeks ago at SFU. After the seminar in the pow-wow, I asked him if he was aware of these works. He replied he had no knowledge of them. How is it possible that climate change Kauna Kevin T and the climate scientists not know of these works? If they do, they never mention them at least on the blogs I have read
You now know of these works.
The above link for “Cyclic Climate Changes and Fish Productivity” is not working.
Here is an alternative one.
http://bit.ly/gTRQsZ
Sorry, try this one:
http://bit.ly/h9xkrG
still better one:
http://bit.ly/gnbQX0
ABSTRACT
Analysis of the long-term dynamics of World Fuel Consumption (WFC) and the Global Temperature anomaly (dT) for the last 140 years (1961-2000) shows that unlike the monotonously and exponentially increasing WFC, the dynamics of global dT against the background of a linear, age-long trend, undergo quasi-cyclic fluctuations with about 60 a year period. No true linear correlation has taken place between the dT and WFC dynamics in the last century. Spectral analysis of reconstructed temperature for the last 1420 years and instrumentally measured for the last 140 years global dT shows that dominant period for its variations for the last 1000 years lies in the 50-60 years interval. Modeling of roughly 60-years cyclic dT changes suggest that the observed rise of dT will flatten in the next 5-10 years, and that we might expect a lowering of dT by nearly 1-0.15°C to the end of the 2020s.
http://bit.ly/gnbQX0
I’m sorry if the following seems jejune. I am just a lurker with no scientific qualifications but I’m interested in the logic of this debate.
When you say something like ‘If natural variability is dominant, the sea ice extent could increase ….’ I find I can’t really grasp what the concept of ‘natural variability’ is. Still less of course do I get ‘natural internal variability’
I presume that ‘natural variability’ is an established concept in this field. Where can I find it explained?
Bart150 — This is a pretty good article on “natural variability”
thanks for this ref, i agree it is a good one
Funny insurance story.
A man returns home from work to find a boulder the size of his car has crashed through the roof of his house, demolishing his home and killing his valuable tropical fish.
There is no other nearby geological feature that could account for this boulder than the cliff a quarter mile away on the site of the construction of a new mall.
It turns out that indeed the cliff was the source of the boulder, which due to a gross blasting miscalculation was catapulted through the air with the resultant destruction landing on the unfortunate domicile.
The insurance adjuster took one look at the boulder, determined that it was natural unfinished granite, and put the damage down to ‘natural hazards’ (insurance limited) and the fish therefore died by ‘natural causes’ (uninsurable).
Once a human hand has significantly moved something, how can its actions still be called natural?
How do we even know that the oceanic oscillations would have had so extreme an impact since 1860 were it not for the CO2 level increase preceding that wildly swinging temperature pendulum north of the tropics since 1750?
Isn’t all we could say is that, were it not for the CO2 rise, we’d be able to certainly not attribute the outcomes to man-made CO2 increase?
Excellent post Dr. Curry. You said:
“If natural variability is dominant, the sea ice extent could increase if the AO stays predominanly negative, the PDO stays cool, and the AMO switches to the cool phase (a scenario that might occur sometime in the next 2-3 decades).
A complex interplay between natural internal variability and CO2 forcing is the most like explanation. Further research is needed particularly on role of natural internal variability in influencing sea ice thickness and extent.”
______
A few thoughts/questions:
It seems some research has indicated that in fact a greater frequency of negative AO might tend to cause a reduction in Arctic Sea ice, which appear in conflict with what you indicate above. Indeed, I take this quote from the NSIDC’s recent Arctic update:
“Through most of January, the Arctic Oscillation (AO) was generally in a strongly negative phase, similar to the pattern that dominated the winter of 2009 to 2010. This led to very warm temperatures over the eastern Arctic, helping to account for the low ice extents over the Labrador Sea and Gulf of Saint Lawrence.”
So which is it? Negative AO tends to increase or decrease sea ice? Related to this I’d be curious to get your opinion about the relationship between a more frequency negative AO and a more frequent Dipole Anomaly. They both seem to lead to a net warming of the Arctic by “opening up the freezer door” so to speak, and allowing even the more severe winters at lower latitudes as the cold air is pushed out of the Arctic. This does seem to make some intuitive sense. We saw this, for example, earlier this winter when the AO went very negative, we had a Dipole Anomaly, Greenland and the Newfoundland area were very warm, but Europe and the East coast of the U.S. were hit with all the cold air that was pouring out of the Arctic. Some researchers seem to indicate this condition could be the result of more open water and the release of heat in the Arctic during the fall/winter period. Your thoughts?
Overall, positive AO causes more ice to be transported out of the arctic ocean. Negative AO reduces ice extent at the margins in the North Atlantic
That seems to make sense, so what you’re saying is the ice export during the positive AO years is net greater than any ice extent reduction during the negative years. But, do either of them have longer multi-year effects? That is, does a negative AO over a period of years tend to mean higher Arctic temps for that period and for certain period thereafter versus what they might be if the AO was positive or neutral?
When it was really cold up there, they both made a lot of ice. Funny how that works.
Arctic Ice follows one of three possible futures:
1. Increasing – the signature of an ice age – glacial period.
2. Unchanged – climate may be either in a glacial or interglacial period.
3. Decreasing – the signature of an interglacial period.
It would appear that what is being observed – Arctic Ice melting – this indicates that current climate is consistent with us being in an interglacial period.
You have made an error of logic. Identical effects do not have to have identical causes. If my drapes move at night, it could be becasue I left the window open and the wind is blowing them or it could be because my cat is walking behind them, or it could be a combination of those reasons (the wind blew the drapes and the cat decided it would make an interesting play toy). So too, Global Climate Models have all consistently shown a decline in year-to-year Arctic Sea ice to be one of the consequences of the 40% greater amount of CO2 that we have now versus the 1700’s. It could be the interglacial, it could be CO2, or it could be some combination thereof.
Happy to oblige
4. Decreasing – we are in an ice age and CO2 is keeping NH cities from being burried under a mile of ice.
Nothing changes
love these headlines
Cartoon that summarizes the historical reporting
http://bit.ly/aVQyxO
For the global cooling from 1880s to 1910s, the headline in The New York Times on 24-Feb-1895 was PROSPECTS OF ANOTHER GLACIAL PERIOD
http://query.nytimes.com/mem/archive-free/pdf?_r=2&res=9F02E1D8163CE433A25757C2A9649C94649ED7CF
Opening this one is worth it for the temp graph alone
For the global cooling from 1940s to 1970s, the headline in Newsweek on 28-April-1975 was THE COOLING WORLD.
http://bit.ly/X403E
…and all of those were followed by increased warming, yet people are still talking about cooling again even now. They haven’t learnt yet.
Jim,
As we are right on track timewise to go from warm to cold, betting on cooler temps seems to be where the smart money is based on historical records.
do open THE COOLING WORLD. The posted graph is worth a look.
Judith: Abstract reads like it is probably a good paper, but declaring it “definitive” is probably not a good idea. After all, aren’t we supposed to agree that the IPCC is the definitive source? (ok,yeah, for 2006 or something?)
I hope to read the full text tomorrow. Perhaps aftwerwards, I might be able to make a more substantive comment. – gcap
Dr. Curry,
What would you estimate as the probability that AGW contributes substantially (for example, more than 25% of the change is due to AGW) to decreased arctic ice extent? If I understood one of the references you cited, at least a portion of the decrease was due to wind driven movement of ice as well as or more so than temperature. What portion of the decrease in ice extent would you estimate is accounted for by movement of ice? In other words, what is the degree of uncertainty that AGW is a major cause of decreased sea ice extent?
Stephen, I can’t put probabilities on this, uncertainties are too great.
According to following paper, by J. E. Box (http://www.astro.uu.nl/~werkhvn/study/Y3_05_06/data/ex6/gl.pdf), warmest decade in Greenland, over the past 150 years, was in… 1930 – 1940…
Exclusive: Berkeley temperature study results “confirm the reality of global warming and support in all essential respects the historical temperature analyses of the NOAA, NASA, and HadCRU”
March 20, 2011
Climatologist Ken Caldeira sent me the following email message for publication this weekend:
I have seen a copy of the Berkeley group’s draft paper, which of course would be expected to be revised before submission.
Their preliminary results sit right within the results of NOAA, NASA, and HadCRU, confirming that prior analyses were correct in every way that matters. Their results confirm the reality of global warming and support in all essential respects the historical temperature analyses of the NOAA, NASA, and HadCRU.
Their analysis supports the view that there is no fire behind the smokescreen put up by climate science deniers.
Note: Caldeira helped fund the Berkeley Earth Surface Temperature Study, but didn’t participate in it.
In one sense, this finding isn’t news, since there have never been any credible challenges to the surface temperature data other than the smoke blown by the climate science deniers.
Indeed, we have very good reason to believe the data that were attacked the most, that collected by the Hadley Center and Climate Research Unit (CRU) of the University of East Anglia, (unintentionally) lowballed the rate of recent warming (see The deniers were half right: The Met Office Hadley Centre had flawed data — but it led them to UNDERestimate the rate of recent global warming).
But in another sense, this finding is news, since the study looked like it was a set-up from the start.
I first broke the story of the dubious nature of BEST back in mid-February — see “Richard Muller, Charles Koch, Judith Curry and the implosion of the Berkeley Earth Surface Temperature Study: How to kill a potentially not-bad idea in 5 easy steps.”
… For a study supposedly aimed at boosting credibility in the surface temperature data record, however, its flaws in conception and operation were beyond head-exploding:
It was co-chaired by Richard Muller (author of widely debunked books, blog posts and Wall Street Journal op-eds). Muller himself has actually worked to undermine credibility in well-established science and doesn’t have a great grasp of basic climate science (see here) or energy (see “here).
Muller got co-funding for the study from the Charles G. Koch Charitable Foundation! It’s hard to imagine a more irresponsible and anti-scientific person than Charles Koch. CP and CAP have long detailed the role of the billionaire brothers of Koch Industries, Charles and David Koch, in destroying American prosperity. We now know Koch Industries outspends Exxon Mobil on climate energy disinformation.
BEST claims its team includes “climate experts,” but the only climatologist listed is Judith Curry, one of the most debunked climate scientists (see Schmidt and Annan and Steig and Verheggen, and CP for starters). Curry mainly seems on the team to give Muller the thinnest veneer of climatology credibility, since she herself has written, “I participated loosely in this project, mostly as a resource person calling their attention to any new papers or blog posts that I thought were relevant and as a sounding board for ideas. As they have begun analyzing the data, I have completely refrained from commenting on the process or preliminary results, I have only made suggestions regarding where they might publish their analyses, etc.”…
Did Ken Caldeira accept a hacked version of the unpublished work?
Or is he a peer reviewer violating his pledge of non-disclosure?
Inquiring minds want to know if he got access to this private report ethically, or not.
Oh, and does that make Joe Romm an accessory after the fact?
orkneygal,
While the troll has tremendous troll-esque characteristics, he/she does not have any posting skills. The troll does not know how to post links, apparently, nor does the troll bother with attribution or sourcing.
Your points are completely valid, but starving trolls is the most productive way of interacting with them.
No, he’s misreporting what he saw
ianash
1) We are not “climate science deniers”. We are man-made global warming deniers.
2) Most of us accept global warming.
3) Most of us accept the data; though, there is some evidence for data adjustment.
My 0.15 adjustment leaves things consistent with this, so you can see where I am coming from.
http://bit.ly/8SPNry
4) One of our main argument is that the global mean temperature is cyclic with an overall global warming of only 0.06 deg C per decade.
Here is the overall warming of 0.06 deg C per decade.
http://bit.ly/euIaVz
Here is what is left from the global mean temperature anomaly after removing (detrending) the overall warming of 0.06 deg C per decade.
http://bit.ly/ePQnJj
This chart clearly shows the detrended data is cyclic. As a result, the longterm global warming is only 0.06 deg C per decade.
As the global mean temperature has a cyclic component, for the IPCC to report the global warming rate of 0.2 deg C per decade during the warming cyclic to continue into the future, without subtracting the cyclic warming component is incorrect.
IPCC:
For the next two decades, a warming of about 0.2°C per decade is projected for a range of SRES emission scenarios. Even if the concentrations of all greenhouse gases and aerosols had been kept constant at year 2000 levels, a further warming of about 0.1°C per decade would be expected.
http://bit.ly/caEC9b
IPCC has exaggerated the global warming rate by a factor of about 3 (=0.2/0.06)!
You could get your information from Joe Romm (and try to publicize it here without mentioning that it comes from Joe Romm, but the ranting style is a giveaway) , or you could get it direct from BEST:
Paul, thank you for posting this, this is from a new statement from the group on its FAQ site:
http://www.berkeleyearth.org/FAQ
Apparently the figure that Caldeira saw was a very preliminary analysis of 2% of the data, for a limited period (a few decades). No conclusions of any sort can be drawn yet, and the full data set has to be analyzed.
Ken most likely saw a CHART or two. the same charts that zeke and I saw.
not a draft paper
Romm’s piece is very misleading. See the statement at the BEST FAQ:
http://www.berkeleyearth.org/FAQ
The Berkeley Earth Surface Temperature project has not yet done the analysis of the full data set with the corrections to produce a global surface temperature trend. We are first analyzing a small subset of data (2%) to check our programs and statistical methods and make sure that they are functioning effectively. We are correcting our programs and methods while still “blind” to the results so that there is less chance of inadvertently introducing a bias.
A preliminary analysis of 2% of the Berkeley Earth dataset shows a global temperature trend that goes up and down with global cycles, and does so broadly in sync with the temperature records from other groups such as NOAA, NASA, and Hadley CRU. However, the preliminary analysis includes only a very small subset (2%) of randomly chosen data, and does not include any method for correcting for biases such as the urban heat island effect, the time of observation bias, etc. The Berkeley Earth team feels very strongly that no conclusions can yet be drawn from this preliminary analysis.
For global temperature, I’ll be most interested in the SST data, since even if land data were substracted, the global trends would not change much, due to their close similarity to the SST trends. UHI effects and other land-based measurements are of greater interest for regional trends, and for the principle of accurate assessment at all levels, but should not be expected to significantly alter global temperature trends.
The Berkeley group is seeking funds to do SST also, but round one is focused on the land surface temps
ianash.
Ken C is misrepresenting what he saw. the draft paper is just starting.
what he saw is most likely the same thing zeke and I saw. a few charts
compiled by looking at 2% of the data.
1. I fully expect BEST to have an answer close to GISS and CRU.
2. The benefits of BEST are as follows:
A. new dataset, including unpublished sources.
This answers several complaints of skeptics and lukewarmers
B. A PROPER statistical method that is superior to CRU and GISS.
C. No ADJUSTMENTS required.
D. Proper uncertainty bounds.
Iananesh, too funny! You go on about how D’ers only say half truths. Well what about you? Almost all Cons whom I have spoken to do not have a problem with the concept that temps are rising. Got that? TEMPS ARE RISING!
Now show me why this is bad, O.K>???????
Ohhhhh.. Romm is SOOOO busted.
Yeah i almost feel sorry for him. It’s quite easy to get caught up in a new ‘story’, but this one has a real case of foot meet mouth to it.
Now lets see him try to dig his way ‘up’…..
ianash | March 21, 2011 at 4:24 am | Reply
Exclusive: Berkeley temperature study results “confirm the reality of global warming and support in all essential respects the historical temperature analyses of the NOAA, NASA, and HadCRU”
So what do I assume from your extraordiary O/T outburst? You now love BEST or do you still hate BEST? Just asking.
Judith,
There are two ways Ice can form.
Precipitation build up(minor) or Under Ice formation which builds up thickness. This becomes a complex problem of understanding when snow can insulate cold temperatures from penetrating under the ice to form more ice.
Winds spread different cold around to different points in the Arctic.
Solar radiation (lack of) interferes with melt and due to angles reflects off the Arctic surface.
Pat Cassen, Curryja
I have studied the article on “Natural Climate Variability” by Michael Ghil, which I understand is regarded as a sound piece of work. It seems to me, an outside critical thinker, that this article has a rather basic defect.
The word ‘Natural’ in the title leads me to expect that there are at least two types of climate variability: Natural and (presumably) Not-natural. So I expect the article to tell me at the outset what the distinction between those two types of climate variability is. But it doesn’t. It just plunges into detail about how climate can vary, and hardly ever uses the word ‘natural’ or its opposite at all. However, in the penultimate paragraph there is a clue when the phrase ‘natural or anthropogenic changes’ is used.
After some thought my guess at what climate scientists really mean, although Ghil doesn’t say it, is the following:
There is climate variability. To talk of “Natural Climate Variability” or, eg, ‘Non-natural climate variability’ is confusing. What you observe is just climate variability.
We can identify factors to explain climate variability.
Some of these variability-explaining factors we classify as ‘anthropogenic’ factors, ie factors attributable, at least to some extent, to humans.
All variability-explaining factors that are not anthropogenic are classified as ‘natural’ factors.
In principle, any given piece of climate variability can be explained in terms of such factors. It may well be that the explanation entails some complex interaction between the two types of factor.
I suppose then that if you say of a certain observed variability: ‘A complex interplay between natural …. variability and CO2 forcing is the most likely explanation.’, then you mean the following:
‘The most likely explanation is a complex interplay between a number of factors: only one of these factors (CO2 forcing) is influenced in any way at all by humans; all the other factors concerned are entirely independent of humans.’
As an outsider I then want to ask: Are you sure that the distinction between these two types of factors is entirely sharp? But this isn’t my field. I’ve probably gone way too far already.
There is forced and unforced variability. forced variability can be either natural or anthropogenic. natural variability can be either forced (e.g. volcanoes, solar) or unforced (e.g. nonlinear oscillations of the coupled ocean atmosphere system). does this help?
If you use an analogy like “Cause of Death” you can see the difference only matters in certain contexts.
From an objective “Cause of Death” standpoint there’s very little difference between someone slipping off a high ledge, deliberately jumping off it to cause their own death, deliberately jumping off it for reasons other than to cause their own death and being pushed off it. The person still dies in almost exactly the same manner.
You can imagine a body of work which describes the various ways in which people die would mention “Natural causes” but generally concern itself with the actual mechanisms and their detection not the circumstances leading upto them. Nor is it really possible to clearly differentiate between a deliberate blow to the head and an accidental one.
In other contexts the attribution becomes important but at the same time the actual death itself and the mechanisms of it become simply factual. Is the ledge unsafe and needs work? Does the person’s life assurance policy applicable or not? Is there a murderer that needs to be caught? And so on.
Continuing with the analogy “Natural causes” often means “No reason to expect foul play or anything suspicious but the person was old/sick and it might have been any number of things that killed them”.
In climate “natural variability” can often mean “We don’t know the exact mechanisms that drive this but there’s no reason to think they’re not natural”.
“Natural variability” is therefore a tempting target for people who for other reasons don’t want there to be any human caused issues. People don’t fall off a ledge and end up with a bullet hole in their head and 50% of the old people in a particular home don’t die of natural causes in a single night.
When people strain to dismiss what are fairly obvious oddities with “Natural causes” it’s time to get suspicious of motive.
Sorry, I didn’t use the “reply” button to properly nest this comment, so I’ll repeat it here to make it clear that it was a reply to Sharper00 above.
On the other hand is there any good reason to be suspicious of the motives of those who ascribe practically anything and everything to AGW?
http://www.numberwatch.co.uk/warmlist.htm
It seems the temptation to strain to attribute is much greater than any straining to dismiss. The great symbol of such straining is the hockey stick, but it surely does not stop there.
Perhaps you would like to describe 3 of your favorite “fairly obvious oddities” that stand out from the noise of natural variation. You can choose from any on the list linked above. I have had a hard time finding any anthropogenic signal in the noise myself, but since you have apparently observed “fairly obvious oddities” I would be pleased to see what you have found.
On the other hand is there any good reason to be suspicious of the motives of those who ascribe practically anything and everything to AGW?
http://www.numberwatch.co.uk/warmlist.htm
It seems the temptation to strain to attribute is much greater than any straining to dismiss. The great symbol of such straining is the hockey stick, but it surely does not stop there.
Perhaps you would like to describe 3 of your favorite “fairly obvious oddities” that stand out from the noise of natural variation. You can choose from any on the list linked above. I have had a hard time finding any anthropogenic signal in the noise myself, but since you have apparently observed “fairly obvious oddities” I would be pleased to see what you have found.
“On the other hand is there any good reason to be suspicious of the motives of those who ascribe practically anything and everything to AGW?”
The number of individuals who do this is small. Personally I only see them talked about rather than ever see them directly.
On the one hand it’s difficult to get any two skeptics to agree on much of anything the full range of the group’s opinion following a fairly extreme range yet on the other hand particular articles and even tweets/facebook updates are used by the same skeptics to represent what the entire group of people who believe AGW is real think.
since you have apparently observed “fairly obvious oddities”
The topic is the Arctic ocean and the oddity is the behaviour of Arctic ice. You may feel like there’s nothing odd going on and you can simply stamp “Natural causes” on another patient and go home early but experts disagree.
Certainly everything that is happening now with Arctic ice has happened many times before without any anthropogenic help. Teasing an anthropogenic signal out of the noise does make me suspicious of motive.
Of course. People die all the time, nothing to see here officer.
I thought we were talking about fairly obvious oddities? No one has pointed out any “fairly obvious oddities” about Arctic ice. Instead you appear to have seized upon a very obvious natural process (a reduction in Arctic sea ice) as being somehow significant enough to justify calling in the police. But there is nothing to separate this “death” from the countless other deaths of natural causes, so why the alarm? Could it be because this obscure event appears to miraculously fit a certain theory (as long as you ignore all the other times the Arctic has melted without help from man).
There is a very apt correlation between this reasoning and the trick to hide the decline. Jones and Mann were all about removing inconvenient information and magnifying anything that remotely seemed to support their hypothesis. Any graph, for instance, of Arctic Ice that ignores or fails to show the cycle of ice ages and presumes instead to show a significant reduction in current levels with a view to promoting the idea that today’s picture is a “fairly obvious oddity” is a trick to hide nature.
There is nothing odd about what the Arctic ice is doing if you take a proper long term view of the thing. We know that we are somewhere near the tail end of an interglacial period. Ice has been giving way as expected for several thousand years, in fits and starts. To observe the actual process for 30 years or even 150 years while the metrics are at geologically expected levels and get all excited about year to year variations within that noise is pretty silly really. It would be like declaring our unfortunate metaphorical victim dead because, between breaths, he isn’t breathing. If you keep calling the police for those sorts of oddities they will soon stop coming.
There is nothing odd about what the Arctic ice is doing if you take a proper long term view of the thing.
Of course. Simultaneously we don’t know enough about the past to say anything odd is happening yet the past is certain enough to say nothing odd is happening.
We know that we are somewhere near the tail end of an interglacial period.
If you’re going to invoke the processes that drive interglacials to explains decadal scale be prepared to show your work.
Everything you’ve said is about dismissing the observed changes in the Arctic. Oh it’s not really changing. Well ok it is changing but you need a long term view. Oh the long term view says it’s still odd? Well that long term stuff just isn’t certain enough.
And just like temperature we end back at “Well we don’t really know for sure”. Of course the “we” isn’t “We experts in Arctic science” it’s “We bloggers with political and idealogical motivation to dismiss and reject anything of that sort”.
Those “natural causes” sure are creating a large bodycount these last three decades. The local mafia is doing a great job with the whole “activist police officers raising your taxes” idea though.
Sharper, it is all natural. Whether it be a species puking CO2 into the atmosphere for its’ betterment, or volcanoes spewing a brew of toxicities, there is nothing that occurs that is un-nature-all.
Sharper00 says:
“Of course. Simultaneously we don’t know enough about the past to say anything odd is happening yet the past is certain enough to say nothing odd is happening.”
What do we know about the Arctic ice. It has been greater, it has been less. We are not at the top or the bottom of whatever cycles are in play. And those cycles have played out over and over without the help of man. So we make some observations that are consistent with what we know, and you choose to call it odd. How odd.
“Of course. People die all the time, nothing to see here officer”
Newly discovered dead bodies without police attendance are unusual.
Meting ice during an interglacial period is not unusual. What would be unusual is when it stops melting and starts increasing. At some point that would signal the interglacial was over. However, if it started melting once again, that would signal we are still in the interglacial, which for most of us is a very good thing. The end of the interglacial, that will be climate change.
Dr. Curry,
Even though it happens again and again, it’s *still* amusing to see the stern rebukes and hurt confusion emanating from your tribe when you dare to suggest that, yes, AGW is real and, in this thread’s case, does contribute to Arctic ice melt.
You do realize, don’t you, that a significant , and frequently-posting, proportion of your readership remains in abyssally deep denial of such facts? Does that suggest anything to you regarding your tactics to date?
well ignoring skeptics and denying their FOIA has been tried for over a decade with pretty crappy results. Let’s give Curry a decade and then decide which works betters
Mosh, you focus on the ‘theater’ — the process and the personalities — not the science. It’s what you do. It’s the modern curse. From the perspective of scientists gathering the raw data, doing the analysis, publishing the papers, writing the grants, hiring the postdocs, teaching the courseloads, attending the conferences, sitting through the committees meetings — doing the day to day work of a scientist — you guys are noise, a distraction. You aren’t discovering significant new facts about the natural world and how it works. You aren’t agitating for better funding for better science (which would actually work towards reducing uncertainties). You aren’t interested in doing so. In those rare instances where you do engage actual science, it’s to rehash and finely comb through previous results, in order to further a rather pathetically obvious nonscientific agenda.
Fact is, Mosh, the substance — the science — has continued to move robustly forward all during that decade of what you call ‘crappy results’. Scientists still be doin’ science while you guys howl away on the sidelines. You guys think you’re the whole story now, but you’re not. You’re just noisy.
Amid that noise, the reality of AGW, and a role for it in polar ice melts, are among the ‘few’ facts I’d hope the increasingly confused-sounding Dr. Curry would continue to pound home to her tribe of howler monkeys. Christ knows they could use some regular reality-checking, and if Dr. Curry’s the one to give it to them, well, that’s too bad for the mainstream who aren’t as endlessly heroically conflicted as she is, but it’s still better than nothing….for now, at least, while she still accepts that there are such things colloquially referred to as ‘facts’ .
“Mosh, you focus on the ‘theater’ — the process and the personalities — not the science. It’s what you do. It’s the modern curse.”
1. This factually incorrect. My focus has been on the following issues over the past 4 years.
A. Open data and Open source and Open debate. yes, I did coin the tagline for lukewarmers ” Free the Code”. That got me involved in FOIA
B. the scientific questions surrounding the global temperature index and UHI in particular. That focus has resulted in more than a few thousand lines of code which are freely available. I also process data for a couple of people who are writing papers. Yes, warmists.
C. The sociology of science and the philosophy of science. So yes,
This involves personalities. That work started Nov 17th 2009.
“From the perspective of scientists gathering the raw data, doing the analysis, publishing the papers, writing the grants, hiring the postdocs, teaching the courseloads, attending the conferences, sitting through the committees meetings — doing the day to day work of a scientist — you guys are noise, a distraction. ”
“you guys”
I would say much of what Some do is a distraction. However, I did note at AGU that there were many sessions on Open data and Open code. Those that I attended mentioned climategate.
“You aren’t discovering significant new facts about the natural world and how it works. You aren’t agitating for better funding for better science (which would actually work towards reducing uncertainties). ”
Before I agitate for more Funding I think its reasonable to have some understanding of who will use those funds and how they will use them.
For example, if they do not intend to open the data and free the code, then I’m not in favor of more funding. I have called for more funding of certain GCM projects. Sicne MY CONCERN is analysis of HISTORICAL data, I never expect to find out any new fact about nature. Science is not as small as you think. I have had some compliments from working climate scientists ( yes warmists) on some help I offer them. So, I’ll take their thanks over your ignorance.
“You aren’t interested in doing so. In those rare instances where you do engage actual science, it’s to rehash and finely comb through previous results, in order to further a rather pathetically obvious nonscientific agenda.”
Since, Hansen2010 has actually made corrections due to the work that a couple of us were doing, I’ll take the endorsement of his corrections over your ignorance.
“Fact is, Mosh, the substance — the science — has continued to move robustly forward all during that decade of what you call ‘crappy results’. Scientists still be doin’ science while you guys howl away on the sidelines. You guys think you’re the whole story now, but you’re not. You’re just noisy.”
My focus is very narrow. it has been since 2007. It’s a question I like. Back in 2007 I explained to gavin that there was no great scientific consequence to the questions I was interested in. Yet he and others have persisted in misrepresenting people like me and our interests.
So, ya we make noise. Now, we get a chance to see if BEST will do things in an open and transparent fashion. 4 years later. For something that doesnt matter, folks fought pretty hard against us. Thats why I argue that the path you guys took ” hide the data, hide the code, fight the FOIA” did MORE DAMAGE than any skeptic could.
“Amid that noise, the reality of AGW, and a role for it in polar ice melts, are among the ‘few’ facts I’d hope the increasingly confused-sounding Dr. Curry would continue to pound home to her tribe of howler monkeys. Christ knows they could use some regular reality-checking, and if Dr. Curry’s the one to give it to them, well, that’s too bad for the mainstream who aren’t as endlessly heroically conflicted as she is, but it’s still better than nothing….for now, at least, while she still accepts that there are such things colloquially referred to as ‘facts’ ”
In 2007, i coined another term, on RC. I described a tactic which I called “running for the ice” here was my point. in the face of STUPID skeptical arguments against our BEST EVIDENCE of warming ( the temp record) many AGW people RUN FOR THE ICE. That is, they do the following:
Skeptic: The land record is unreliable!!!!
AGW : Look at the ice!
I argued that this was an epistemological and rhetorical mistake. Why? because the evidence the ice presents is
A. shorter
B. Confounded by influences other than warming.
to be sure, in a warming world we expect there to be changes in the arctic ice. But our understanding of the ice is far less certain than our understanding of what added GHGs do. the IPCC even says so.
So WHY would a smart person resort to slippery evidence, when the better evidence is just the temperature record. That shift, that running for the ice, made no epistemic sense to me, or rhetorical sense to me.
it was a stupid response to skeptics. Now, I also told skeptics that it was stupid to focus on the ice. See my REPEATED comments to goddard about this point.
As far as the debate goes, focusing on the ice and on the HS are just mistakes. I think people who believe in AGW (like I do) are being stupid when they focus on the less reliable evidence. I think doing a more credible job, a more open job, a more complete job, a more perfect job on the best evidence ( the temperature record) is more important than creating noise and confusion with “ice death spirals’, “hockey sticks” and “unprecedented” events. Those issues cause more confusion, not less.
To sum up: Scientists who want to work on unsettled and complicated issues (ice, reconstructions, extreme events, natural variability) are doing one kind of science. Their findings are important, BUT they are not really moving the debate forward. They should get a bit more certainity before speaking or before trying to make their evidence part of “The case”. Scientists who have worked on the boring stuff, the temperature record, would be well advised to polish up their work, bring it up to better higher standards of completeness and perfection. Engineer it, in other words. ever wonder why there are a large number of engineers in the skeptic camp? or lukewarmer camp?
I think doing a more credible job, a more open job, a more complete job, a more perfect job on the best evidence ( the temperature record) is more important than creating noise and confusion with “ice death spirals’, “hockey sticks” and “unprecedented” events.
steven mosher: That would work for me. Great post.
The theater-and-personalities aspect of climate change remains an issue because it is easier for most people to understand and because climate scientists keep making excuses for the personalities and digging in against reasonable requests for openness, which quite naturally arouses suspicion.
Openness and high standards wouldn’t satisfy all skeptics, but it would be persuasive for many such as myself. It baffles me that climate scientists, given the stakes of climate change, don’t dig in and handle this, instead of complaining about big oil, deniers, and talk radio.
I’m an engineer.
“You aren’t discovering significant new facts about the natural world and how it works. “
This. A thousand times over. The actual natural world gets almost immediately drowned out on the blogosphere.
“Fact is, Mosh, the substance — the science — has continued to move robustly forward all during that decade of what you call ‘crappy results’. “
I think of it like this: There’s a TV show called “Climate Science: Las Vegas” which is written by an ad-hoc network of bloggers. There are all sorts of characters written on the show and all sorts of plots with all sorts of dramatic twists.
Unfortunately the fanbase for “Climate Science: Las Vegas” is much much lager than that of actual climate science and what’s worse fans of the TV show think the plots are real life. If you write about the TV show people will flock to your blog to discuss it and their favourite characters, if you write about climate science people won’t have a clue what you’re saying or much care.
Regardless of the TV show plots, made ever more dramatic to keep the viewers happy, the actual scientists continue on.
“Scientists still be doin’ science while you guys howl away on the sidelines. You guys think you’re the whole story now, but you’re not. You’re just noisy.”
Hmmmm,
So worried about what’s happening on the sidelines… why would that be? Why so defensive about people wanting to check out the truth for themselves? If the science is so lock solid…. just sayin.
Oh dear. You’ve confused *contempt* with *worry*. Glad to help you out here. I’m not *worried* at all that climate science is collapsing or will collapse like a house of cards, much less ‘any day now’ like the feverish howlers like to claim. If anything I’m *worried* that the uncertainties in the science are in the worse direction…e.g., climate sensitivity is actually at the *high* end of the range. Because uncertainties cut both ways. Has Dr. Curry expounded much on that?
(Regarding the ‘theater’ rather than the science, I only *worry* when the invincible arrogance and paranoia of the theatrical howlers percolates to ignorant and/or craven politicians who can wage battle by financial and legislative means. Fortunately science has tended to win those battles too.)
Off the cliff the herd.
Cowbell Morgan hears a Moo.
Climate Science Seuss!
============
Whoa, ‘Cowboy Morton’. Where’s the methyl xanthines?
==================
yeah,,,you guys do not like to be checked, unlike people in the real world. You are not Gods to be worshipped. You do not deserve respect. Earn it, as we folks in commerce do.
stephen…maybe the daily payload means you are no longer a researcher…you are a teacher. re-define your job.
Hrm. Maybe you’ll make some sense, some day.
Steven, I do not align myself with any tribe. I ackowledge few actual “facts” in all this; there is ambiguous evidence and much uncertainty.
Prof Curry
Go get recent atlas of the earth. After a short study of the atlas, you will come to these conclusions:
1. There are few humans on the earth.
2. Humans occupy a small fraction of the earth’s surface.
3. Humans have permanently modified a quite small fraction of the earth’s surface by construction of cities and urban areas, highways, dams, harbors, etc.
4. About 50% of humans live in cities and urban areas.
5. Most major cities are located near coasts or large bodies of water.
6. Humans are moving in ever increasing numbers to urban areas.
7. The majority of humans live in poveerty.
FYI: The surface area of Canada is about 6 trillion acres upon which reside about 33 million humans, i.e., the country is unpopulated by humanss. Ditto for Siberia.
I don’t want to read or hear any foolish comments that humans are causing “global warming” or “climate change”because it is just not physically possible.
LOL Harry!
How about, take a couple hundred Anthrax bacteria. introduce these into a human body. Blah-blah-blah….the body is uninhabitated by this bacteria. Therefore I do not want to read or hear that humans “die” or get “crippled” by anthrax, because it is just not physically possible!
:)
Please don’t call me Harry! My nicknames are Hop, Hoppy, Hopper or Mouse Ears!
You sound like a greenie who claim humans are the scourge of the earth and should be eliminated.
DeNihilist,
I think Agent Smith makes your point much better:
There is certainly no shortage of skeptics here. Perhaps their appreciation of this site and frequent visits can be attributed to the somewhat frosty reception they receive elsewhere.
However, there are plenty of non-skeptics here as well. It’s what is called in polite circles a ‘conversation.’ It seems new to you because it is forbidden on the weblogs you normally visit, such as CP, RC, ad tedium.
Tom,
Speaking of conversations, perhaps you would be so kind as to reconsider your blog?
“stern rebukes and hurt confusion?”
As a conservative skeptic, I probably disagree with Dr. Curry on most political issues, and I think the claims of AGW are even more uncertain than she does. However, my comments here have never been deleted or edited, and Dr. Curry has answered courteously and respectfully when I have asked her questions directly.
This is clearly a foreign concept to some. Speaking like an adult to those who disagree with you is seen as a weakness for the true believers. They see everybody yelling at each other on TV talking head shows, and their heroes teach them that ridicule is the proper response to disagreement. Condescending snide remarks are thought the epitome of wit. Each sheep in the flock gets to fancy himself a wolf, as long as he disdains the heretics loudly enough.
Well, that’s OK. They will need their self-satisfied egos to keep them company as they sink into political irrelevance.
SS,
What is more amusing is the willfully ignorant arrogance of true believers like yourself.
As a rational skeptic I genuinely enjoy and do encourage warmist comments on this site. If our interpretation of the data is so weak that it cannot be challenged what is it worth? What value would there be in reading a load of self- congratulatory drivel? Lets invite and evaluate their strongest arguments and witness scientific knowledge growing before our eyes. Obviously they will be more likely to comment if their opinions are treated with respect. And if one must rebuke, try to make it witty.
” If our interpretation of the data is so weak that it cannot be challenged what is it worth? ”
Quote of the week, An excellent motto for a scientist to live by.
May I draw people’s attention to
http://icecap.us/images/uploads/The_failures_part_1.pdf
Here Joe D’Aleo points out that AGW is not” global”. Antarctica tends to be cooling; the southern hemisphere is staying at about the same temperature; the northern hemisphere is warming, with a lot of warming in the Arctic.
It seems to me that this phenomenon needs explaining before we can really address whether what is happening in the Arctic is due to CAGW.
Jim,
Tying climate science globally is a fool hearty adventure at best. The diameter of the rotating equator is the biggest areas of mass and all other areas are subsequently smaller.
This planet is not a cylinder but a globe. And it moves. Not like the stationary pictures or experiments.
“The diameter of the rotating equator is the biggest areas of mass and all other areas are subsequently smaller.”
That is an interesting observation. The mercator projection we are used to seeing for the earth seriously distorts the size of the polar regions and understates the size of tropical regions. The mercator projection became popular because it preserves compass headings for navigation. However it distorts the relative size of polar and equatorial regions.
Africa is a huge land mass which most of us do not realize because of the way it is shown on maps. In contrast, Greenland which appears the same size on maps is actually 14 times smaller. This gives us a distorted view of the world, giving the impression that the polar regions are more important than they really are.
http://en.wikipedia.org/wiki/Gall%E2%80%93Peters_projection
May I point and laugh at the silliness you’re drawing attention to? D’Aleo? Seriously?
Comments on the link you’ve provided:
http://www.skepticalscience.com/Why-we-have-a-scientific-consensus-on-climate-change.html#44900
http://www.skepticalscience.com/Why-we-have-a-scientific-consensus-on-climate-change.html#44901
Background that would have equipped you to know why the link you’ve cited is trash:
http://www.skepticalscience.com/global-warming-scientific-consensus-intermediate.htm
Steven, thanks for those impartial links you posted. I’m really impressed. Boy did you do for ’em!
Steve –
If skepticalscience is the best you can do, then you’re not doing well. Try a real source – ANY real source.
SS,
Thank you for demonstrating willful ignorance in action.
Judith,
A fascinating area of study is speed and time.
For example:
If the crust under the ocean took a month to shove 10 meters on a fault line, then the oceans would dissipate that change as the process is slow. But when it is instantaneous, the oceans cannot dissipate the water volume at that point over time and is transfered ocean energy.
The flexibility of ocean elasticity is interesting with the pressure added with depth. Theoretically it is possible to transport pressurized energy to the surface BUT the elasticity of the ocean has to be broken for that to be achieved.
Polyakov has heaps of interesting stuff on his website.
http://www.iarc.uaf.edu/people/igor
I did a little bit of climate sciencist pestering last year after reading some of his work and asked him about arctic ice variability in an email. He replied saying his estimate for recent trends (since late 1970’s) is 50% natural variability and 50% climate change but a greater role for climate change in the past decade. Not sure if this chimes with the outlook of this multi-author paper.
Separately. I’ve got a question about the paper itself. It seems to have a multitude of ‘names’ in arctic climate science. As if this is the consensus writ large. I’d noticed other similar multi-author papers and reviews on other subjects which seem to be attempts at bringing the big names in a particular field to give a consensus view. Other examples are
Model forcing (this one may just be a technical exercise)
http://www.geosci-model-dev.net/4/33/2011/gmd-4-33-2011.html
Solar/climate (again nominally rivals in the field coming together)
http://scostep.apps01.yorku.ca/wp-content/uploads/2010/07/Gray_etal_2009RG000282.pdf
I’m not trying to get conspiratorial here but is this normal? I know science is collaborative but it’s also largely adverserial as well. I don’t know that such large groups of rivals get together for love ins like this in other science disiplines. Do you have any thoughts on this issue?
When it comes to historical temp reconstructions, I’m wondering why there are not more references to the work of Dr. Patterson and his team from U of Sask. Or anyone else using oxygen isotopes (mainly, w/supporting proxies) for high-resolution climate reconstructions down to seasonal variations. Is there some doubt in the science?
There appears to be some conflicting evidence, RE: above,
“The warming event around 1500 A.D. is identified by climatic simulations in the Atlantic sector of the Arctic and is explained by the internal variability of atmospheric circulation. ”
Compared to:
” . . . grain cultivation had also been established throughout much of the country shortly after settlement but became limited to barley (a shorter-season crop) by the early 1200s, and by the 1500s it was abandoned altogether . . .”
That quote is from ‘Two millennia of North Atlantic seasonality
and implications for Norse colonies’:
http://www.pnas.org/content/early/2010/03/02/0902522107.full.pdf
Within the same article is this:
“Recent investigations of the marine environment off the northwest and northern coasts of Iceland have revealed significant millennial-, centennial-, and decadal-scale variability over the Holocene (14–19). These hydrographic changes on the north Icelandic shelf reflect larger scale ocean atmosphere circulation changes and regional climate variation
in the North Atlantic.”
And this:
“On the basis of δ18O data, reconstructed water temperatures for the Roman Warm Period in Iceland are higher than any temperatures recorded
in modern times.”
Are there any other papers on temp reconstructions in Greenland &/or Iceland using mollusk/isotope values? This process seems to be far more accurate (reliable?) than anything I’ve read re: tree rings or any other temperature proxy. Or am I misinformed?
I’d appreciate the thoughts of commenters here on isotope reconstructions.
-barn
This process seems to be far more accurate (reliable?) than anything I’ve read re: tree rings or any other temperature proxy. Or am I misinformed?
You are misinformed in the belief that the tree ring data was every intended to give an accurate history of temperatures. The intent of the data was to show that curent temperature change was unprecedented. The way to do this was to choose the correct proxy, and then limit the sample, until the correct effect was located. The “hockey stick” was born. It was used as a tool of advocacy, supporting the need for a transfer of trillions of dollars from rich to poor countries, and the creation of “green” jobs for friends of government as a means to cement political power through patronage.
Surprised no mention so far of the Catlin Surveys.
Anyone wish to comment on this with regard to the topic?
Bart R,
“Catlin survey” is a punchline to a bad joke.
hunter
Punchline?
You mean http://wattsupwiththat.com/2009/10/15/top-ten-reasons-why-i-think-catlin-arctic-ice-survey-data-cant-be-trusted/ ?
As fine a piece of poisoning the well as one could ask.
So, do I look for information about a place from alleged wingnuts who actually go there, or alleged wingnuts who appear allergic to first-hand information of any sort, be it expedition, measurement, or experiment?
Why would you look to either one for answers?
Peter317
In climate, everyone is someone’s alleged wingnut.
so who’s wingnut am I then?
Just curious…
Peter
So many ways to read that question.
As it is better to suffer for doing good than for doing evil, (Peter 3:17ishly), you’d almost certainly find those who consider those who quote scripture wingnutty would find you so, in this measure.
Otherwise, whose wingnut do you want to be, Peter?
I’m sure they’d be glad to accommodate if you let them know.
wtf has quoting scripture got to do with anything? And wtf has it got to do with me?
Bart –
You go to people who actually know what they’re doing. What the Catlin survey did was utterly stupid for more reasons than you have toes – and fingers.
I take it you didn’t follow their adventure? It truly was a joke.
Jim Owen
I believe I have more fingers and toes than some members of the expedition have remaining.
But please, be specific, be detailed, offer critiques based on information, logic and observation that we all can judge.
And do you mean their 2009 adventure, their 2010, or their 2011?
Have you been to their website?
Listened to their interviews?
Looked past the third-hand reports of some bloggers or the really silly bits of popular newspaper reporting?
Have they ever published anything peer-reviewed, or independently audited? If so, what, where?
Links, not wisecracks.
If I want wisecracks about people travelling north of the Arctic circle, I can just visit with family.
Anyone?
In order –
2009
yes
yes
yes
They did nothing that was worth peer review. If I wanted real information about Arctic conditions, I have better sources – without the drama queen garbage.
They’re an accident waiting to happen. In addition to endangering the lives of others. If you knew anything about living in winter/Arctic conditions you’d know better than to ask those questions.
As for WUWT – your attitude places you on the spectrum. But that’s your problem, not mine.
Jim Owen
These answers seem to match everything I can find or deduce.
Which is why I asked.
They do make one wonder.
Their website does seem awfully vague, navigation-challenged, and short on usable content.
I’d worried that the lack of finding published results was due my search methods rather than the lack of publishing on their part.
I don’t mind drama queens.
If I did, I certainly wouldn’t visit blogs at all.
Catlin surveyors do appear to be participating in an awfully disproportionate level of high risk behavior compared to their output.
I’d just set that down to them being British. I must be on the spectrum about the British, too. But that also is my problem.
Still, they’re there, ill-advised as that is for the Arctic.
I’ll still take eyes on the ground over armchair quarterbacks any day, for all that.
How about the 2009 German aircraft survey that did more science in 12 hours than Catlin has done in ??? – how many years? Eyes on the ground can only cover so much ground – or ice, as the case may be.
I enjoy a good joke – but Catlin doesn’t qualify as “good”. People who put other lives at risk never are.
Hmmm – and drama queens are annoying. They’re shrill, have no sense of either history or proportion, and lack the common sense that God gave a porcupine. That’s why we’re all here instead of playing poker and drinking good whiskey – too many climate drama queens.
Oh yeah – you don’t know that, do you. In an IQ contest between a porcupine and a rock, the rock would win.
Jim Owen
I’ve had to put some time into thinking your points over.
How about the 2009 German aircraft survey that did more science in 12 hours than Catlin has done in ??? – how many years?
And you speak German?
Were you on aircraft in 2009 over the North Pole?
Could you link to the German science and comment on its details directly and specifically?
Why only the German study?
Is it the only recent flyover or other Arctic cruise-by to produce data and studies at all?
Surely with your expertise — what is your Arctic expertise again? — you must know of other recent adventures?
Handwaves don’t qualify as science, too.
Eyes on the ground can only cover so much ground – or ice, as the case may be.
Eyes on the ground can touch, taste, smell, take direct measurements of material qualities.
Aircraft can only ever take proxies of these, and produce little more information than satellites.
By your own reasoning, the Germans take unreasonable risks to send flyers, while there’s satellites.
One could argue that good reasoning can produce the same conclusions as satellites, without the risk of launching rockets.
So all we really need is for the denizens of WUWT to _think_ about the arctic, and have no risk at all?
I enjoy a good joke – but Catlin doesn’t qualify as “good”. People who put other lives at risk never are.
Catlin’s putting other’s lives at risk?
Who?
You mean the lives of rescuers who work in the Arctic? Could you be detailed and explain what exactly you’re saying?
I can think of others who put rescuers at great risk without leaving their homes or workplaces, by storing dangerous goods and practicing poor safety.
Hmmm – and drama queens are annoying. They’re shrill, have no sense of either history or proportion, and lack the common sense that God gave a porcupine. That’s why we’re all here instead of playing poker and drinking good whiskey – too many climate drama queens.
In climate, everyone is someone’s drama queen.
Oh yeah – you don’t know that, do you. In an IQ contest between a porcupine and a rock, the rock would win.
Is this a slam on hedgehogs?
So far, measured against the very little the Catlin people have produced yet, you’re not doing terribly well in comparison on the drama or the science scales, Jim.
The idea that boots on the ground might be bad is not new. George Bush learned that you don’t want to send people to look for WMDs that aren’t there.
If you’re trying to dissemble, you’ll discourage boots on the ground, and denigrate first-hand field observation.
Which makes a skeptic automatically distrust those who denigrate first-hand field observers and disparage the practice of direct observation.
Bart R,
Please do show us their scientifically valid findings.
Perhaps I think Catlin is a joke becuase….it was a joke.
Please show me where I am wrong.
And quoting WUWT as a means of dimissing the criticism of the Catlin adventure is simply diong what you accuse WUWT of doing.
Your dimissive ignorance on this is rather telling.
hunter
To paraphrase Spacequest, it doesn’t take good science to dismiss a bad smear.
Huh.
I must apologize.
I meant Tim Allen, in Galaxy Quest. Of course.
Bart R,
If I were losing as badly as you are, I would also try to get a trivial pursuit game going.
hunter
I’ve been losing this badly for many decades.
Catlin’s arctic follies are only three years old or so.
I’m unlikely to get better at losing.
They have nowhere to go but up.
No – if they keep it up, they’ll likely end up going down. Wonder how deep the Arctic Ocean is, anyway. No matter – it’s deep enough if they don’t get smarter.
Jim Owen
That would certainly demonstrate thinning of the sea ice somewhere.
So, could you maybe offer a list of some of those who are observing the sea ice directly in the field, taking measurements and doing observations, who you acknowledge are doing any part of that process right, at all?
Bart
are you really so surprised to see no mention of the self-aggrandizing Catlin mission? My company, at that time, used that mission to proclaim how eco-friendly they were. That mission had nothing to do with science. It was all to do with “feel-good”. if they could have hugged some polar bears and giant pandas, the mission would have worked. Unfortunately science got in the way by providing real evidence…and I do not mean “real” science as in realclimate science. I anm sure that Connolley was with them all the way.
Graeme
We’re not overall a lot that’s shy of finding and finding fault with obscure efforts and endeavors in the field of climate.
While it would be great to see a catalogue of all the many observers and inhabitants of the Arctic past and present capable of rendering reports about the sea ice and ranked by reliability, scope, utility and relevance, it isn’t in my power.
Best I can offer is a name here and there I’d heard in some context, and questions pertinent to same.
I mean, it was the Catlin Survey, or Jules Verne’s Journey to the Center of the Earth. I went with the more current one.
I know what you mean, Bart…the professional scientists are not good at showing what they really know and what they just assume. So we send out teams of madmen to do stupid things to show what is happening to the ice. And then we wonder why we do nhjot know what is happening, because the amateurs fell into the water
WordPress is having problems, i can’t get onto the dashboard. if you are having problems, this is why; send me an email if you like.
i am confused. This global temperature stuff is a meaningless index. it does not tell you which specific regions are warming or cooling. What we need to know are the regional variations, surely, given that temperate and equatorial climates differ so greatly?
RE: “What we need to know are the regional variations . . .”
Yes. Full stop. Unfortunately lost in the AGW wars are the really important things we need to know that we can actually use. IE: reliable forecasts for agriculture to recreation.
From my reading (and again I go to O isotope research until I read proof that I shouldn’t) that high CO2 concentrations (in the past) have lead to higher winter snow falls in the Great Lakes region that I live in (Toronto ON there abouts) . . . perhaps we can move to an era of information instead of hyperventilation . . . currently we are now gathering more info than ever but apparently we’re reluctant to put it together in any useful way. Sad really, when you think about it . . .
-barn
Where climate change is hitting first is the Arctic. Take a look at any web page on climate change in Alaska, for example, but also Siberia, Greenland, northern Canada. It is already about as obvious as can be there.
Here is a link to an earlier study by Igor Polyakov et al.
http://journals.ametsoc.org/doi/full/10.1175/1520-0442(2003)016%3C2067:VATOAT%3E2.0.CO;2
This study attributes the observed temperature cycles in the Arctic to a natural low frequency oscillation (LFO), rather than to human CO2 emissions.
Just another study with another conclusion.
Max
I would like to try again at getting the opinions (as opposed to wise cracks) of those here on oxygen isotope based temperature reconstructions for Arctic/Greenland/Iceland.
Previously I posted a link to one such paper:‘Two millennia of North Atlantic seasonality and implications for Norse colonies’:
http://www.pnas.org/content/early/2010/03/02/0902522107.full.pdf
I am very interested in the learned opinions here as to the science of isotope reconstructions. Have I been misinformed as per accuracy re: high-resolution down to seasonal variations? (Actually they claim to be able to go down to either weekly or daily resolutions(!) I’ve forgotten which . . . but still impressive.)
There seem to be some major discrepancies between the O isotope reconstructions and what I’ve read here re: temp records.
Unless there is good reason to discount the work of those using O iso recons. there would seem to be little (or no) evidence to indicate recent warming (or cooling) is in fact unprecedented in anyway.
I would greatly appreciate some learned opinion on the O isotope temp recon process. Is it . . . well, for real or what?
Thank you for your time and efforts.
-barn
Further to a previous post, we know that climate change has been a (major) part of human evolution and expansion. How is it that whatever temps now recorded in the Arctic can be seen as dramatic (&/or unprecedented) when we know that we went from vineyards in Greenland to abandoning the settlements entirely because of climate change? Climate change that had nothing to do with burning fossil fuels.
Just ask’n . . .
-barn
BTW: We’re only a short time away from realizing that fossils or better, those that made them, had nothing to do with the creation of oil or natural gas and that both (& all hydrocarbons) were simply created as the planet was . . . there is a theory that if you drill anywhere on Earth – deep enuff – you will find oil. Yes, I understand how this undermines the theory that previous mass extinction via climate change now threatens mass extinction via climate change . . . but still somebody should look into it . . .
BEST-gate has erupted.
http://climateprogress.org/2011/03/22/climate-science-deniers-berkeley-temperature-study/
Some really angry people at Berkeley – not happy about having their name dragged in the mud by Muller and Co.
You lie down with dogs…
For ‘climate progress’ to be up in arms means BEST is very likely going to be a very good study.
Congrats on learning to post links!
A whole universe of derogatory suffices available, can no one use any but the trite and inept -gate?
BESTink? BESTangle? BESTrangement? BESTrayal? BESTruction? BESTruption? TemBEST in a teacup? BESTfamation?
I’m not quite certain what immorality is being claimed.. is someone alleging that people interested in a topic are talking to each other?
How did that get wrong again?
Hi Judith
A really interesting article-thank you.
I wrote about the Arctic ice melt circa 1815-60 when the Royal Society mounted an expedition to investigate the causes.
http://wattsupwiththat.com/2009/06/20/historic-variation-in-arctic-ice/#more-8688
It is well referenced with lots of links and sources including Hudson Bay records, scientific surveys, records from whalers and observations by other fishermen, who of course were very aware of changing climate as it affected the position and type of fish they could catch. Our local town (on the South West Coast of England) is a fishing port. Their men folk being away for a few days locally or on some great fishing expedition that lasted months, had a profound effect on the role women took in local society. Plymouth has records of the fish catches dating back to the 13th Century.
My article is interesting for the map used right at the start. The Arctic is uniquely encircled by countries and as there are numerous parts to it they become vulnerable to destruction of ice by wind, tides, current, storms etc which vary greatly year by year.
One of the earliest books I acquired in researching my article came from the 1820’s and remarks as to how the ice was affected by winds, how warm the sun was, how glaciers had obviously retreated and how the locals had seen a great change in the climate.
There is an intriguing local input and continuity to the Arctic story together with a wealth of credible information which suggests to me that should anyone have the resources, the threads of history could be stitched together to form a coherent account of the Arctic over the last 2000 years, albeit there are some notable gaps. Some of those ‘threads’ are described below.
In 1817 when Sir Joseph Banks of the Royal Society heard that whalers had reported that the ‘Arctic was melting’ this included reports from whalers from my own home town. Banks was especially interested as he had sailed with Cook in 1768 and was intrigued by the notion of a North West passage as that might reveal ready access to new sources of botanical specimens (Banks was a keen botanist). He had heard sporadic reports of this melting in the previous 20 years but the Navy was unwilling to explore having better things to do in fighting those pesky Yanks and Frenchies…
He knew the person –Scoresby-who gave him the latest report and mounted an expedition which is reported in the link above. Scoresby is buried only some 7 miles from my current home. There is a plaque to him on the church wall acknowledging his scientific achievements in the Arctic (he wrote several books) Next to this is another plaque commemorating the death of someone who had sailed on the Titanic. My house looks onto the grand home this family owned. The Titanic heralded the start of the next great Arctic warming that was written about here by Dr Arnd Bernaerts .
http://www.arctic-heats-up.com/chapter_1.html
My wife teaches at a nearby school which contains an ancestor of one of those who secured a prize for traversing the North West passage, although a repeat expedition a year later killed them.
Previously we lived close to the birthplace of King Alfred (circa 871 AD) and there are good accounts of him meeting with Vikings who told him of this wonderful new land of Greenland. The mildness of the climate and the expansion of their activities directly caused incursions by them into England, and the boundary of Alfred’s and the Viking kingdom ran through the River Thames 100 yards from my home.
The Viking era is too well known to warrant repeating as regards their habitation of Greenland and journeys to Newfoundland. Of equal interest is that other great civilisations also inhabited the Arctic region;
From the Eskimo Times Monday, Mar. 17, 1941
“The corner of Alaska nearest Siberia was probably man’s first threshold to the Western Hemisphere. So for years archeologists have dug there for a clue to America’s prehistoric past. Until last year, all the finds were obviously Eskimo. Then Anthropologists Froelich G. Rainey of the University of Alaska and two collaborators struck the remains of a town, of incredible size and mysterious culture. Last week in Natural History Professor Rainey, still somewhat amazed, described this lost Arctic city.
It lies at Ipiutak on Point Hope, a bleak sandspit in the Arctic Ocean, where no trees and little grass survive endless gales at 30° below zero. But where houses lay more than 2,000 years ago, underlying refuse makes grass and moss grow greener. The scientists could easily discern traces of long avenues and hundreds of dwelling sites. A mile long, a quarter-mile wide, this ruined city was perhaps as big as any in Alaska today (biggest: Juneau, pop. 5,700).
On the Arctic coast today an Eskimo village of even 250 folk can catch scarcely enough seals, whales, caribou to live on. What these ancient Alaskans ate is all the more puzzling because they seem to have lacked such Arctic weapons as the Eskimo harpoon.
Yet they had enough leisure to make many purely artistic objects, some of no recognizable use. Their carvings are vaguely akin to Eskimo work but so sophisticated and elaborate as to indicate a relation with some centre of advanced culture — perhaps Japan or southern Siberia —certainly older than the Aztec or Mayan.”
This link leads to the Academy of science report of the same year regarding the Ipiutak culture described above
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1078291
Interestingly Pytheas- who articulated the concept of tides- also visited the Arctic (around 300BC) , sailing one days north of Iceland. Pytheas also visited Britain and commented on the tin trade in the next county to mine of Cornwall with particular reference to St Michael Mount-a tidal island.
http://en.wikipedia.org/wiki/Pytheas
I have written separately of this as it is evident that, taking all other factors into account, the sea levels were higher at that time than they are now. St Michaels Mount is renowned for its mild climate from which I have bought succulents for my garden. Their plants and mine were destroyed in the exceptionally cold winters experienced over the last three years here. As were specimens of plants with the suffix Banksii-discovered of course by Joseph Banks…
Interestingly the mean average of 2010-the last year of the CET record-was exactly the same at 8.83C as the first year of the record in 1659.
There will be some reading this that will say this is all ‘anecdotal’. However they will happily accept scientific analysis based on the historic Hadley/Cru records of Sea surface temperatures. These must be the single most unreliable set of figures that have ever been promoted as a scientific measure yet they have a greater credibility than cross referenced contemporary accounts. It’s a funny old world.
tonyb
Most interesting thank you. And I can’t help comparing the anecdotal evidence to that of the reference of barn E rubble – http://judithcurry.com/2011/03/19/pondering-the-arctic-ocean-part-i-climate-dynamics/#comment-57146 – thanks Barns.
Barns was asking about the oxygen isotope methods. The bivalve micromilling technique looks wondrously precise and I couldn’t help but try to compare dates. Pytheas’ voyage falls squarely in a cold period which does nothing for the thesis. Oxygen 18 ‘values of the two oldest bivalves in our study record a cold period from ∼360 B:C: to 240 B.C. that exhibit some of the lowest temperatures of our entire time series.’ However, I think that they might need more bivalves rather than you needing to change your narrative just yet.
Thanks, I really enjoyed reading your comments tonyb.
The mysteries in Arctic climate are fascinating and what’s under the ice is equally interesting. Its a shame so few have put an effort into explaining the geologic formations on the ocean floor and surrounding coastlines?
International Bathymetric Chart of the Arctic Ocean
http://www.ipy.noaa.gov/education/4-Posters/ibcaoposter.pdf
I particularly enjoyed your comments related to Alaska. From what I’ve read, archeologists have dated tools found at various Alaska sites to as early as 14k bp. Many of the Alaska national parks were created to preserve the sites.
The Bering land bridge, caused by the drop in oceans during the last glacial, had a dramatic effect on the Arctic ocean, Atlantic, and uncovered large expanses of Arctic shoreline.
Mammoth ivory was mined in the late 1800s from islands off the coast of Siberia in the Arctic and has also been found at many of the Alaska dig sites. If one considers the amount of fresh water and fodder a 5-7 ton Mammoth requires, their presence, in large numbers, along Arctic shorelines during glacials becomes extremely difficult to explain.
Computer models aside, IMO the concerns over seasonal Arctic sea ice are largely unfounded and overblown.
TonyB
Thanks for a very interesting article with links.
Yes. It is a shame that historical data is simply being written off as “anecdotal” while paleo-climate reconstructions are taken as “gospel truth”.
There are also many historical records of past warmer periods in the Alps (where I live), including a report of a medieval gold and silver mines being covered up by ice and snow at the onset of the LIA. Receding glaciers reveal physical evidence of past vegetation under the ice and, in rarer cases, of past civilization, including in one case the remains of an old mine.
Then there are the remains of Viking farms found in the Greenland permafrost, which are directly pertinent to this blog.
Thanks for your historical perspective on a topic where we have myopically concentrated on paleo-climate evidence but neglected the historical record, which may actually tell us much more.
Max
A very well put together article on the arctic Judith.
After looking at the various cycles and where they might be come Spring and summer and current state of play in the Artic after looking at real time modis etc I have to agree with the likes of geo that the thin, cracked ice will not protect it enough when WAA comes into place June onwards and a breach of 2007 looks very likely.
I disagree Iceberg.
We’re likely to remain in the La Nina cycle for most of 2011. Sea Ice minimum in Sept.-Nov. this year is not likely to be anywhere near 2007 due to the concentration build up and below normal temperatures.
Just in case anyone thinks its “warm” in the Arctic (currently -20), here’s a live view from Barrow, AK. Not my idea of a great vacation spot at this time of year.
Barrow, AK Webcam
http://seaice.alaska.edu/gi/observatories/barrow_webcam
Whether it’s warm or not on a particular day in your location isn’t really the point, the arctic as of today is now loosing ice, extent is the lowest or near lowest on record and if you look at the ice itself in 250m res on modis etc the fragility is there for all to see.
Re ENSO La nina is currently plumpting back to netural with a now postive anom heat content and weekly figures of -0.8 so just barely la Nina now and futher falls over the coming few weeks will likelylead to neutral conditions by mid April. Of course the 3 month lag used for Zone 3.4 figures will lag by (yep you guessed it 3 months) and will continue to show La Nina for a few more months yet despite what the ENSO zone is currently doing.
US Navy reports that ice rebound (increased depth) has been dramatic. Their models appear to be calibrated every 120 hours based on satellite observations. What a novel approach ; )
I’m just saying, I don’t buy into the thin ice claim nor do I buy into its likely to be unusually “hot” up there this year.
I guess we’ll see who is right in September.
Sea Ice Reference page:
http://wattsupwiththat.com/reference-pages/sea-ice-page/
IMO, conditions are just not unusual. I’ve been following the sea ice story for several years, its actually a pretty boring story. It melts and freezes over each year. Where’s the problem?
If you follow the arctic ice story through WUWT then I can totally see your point, however as Judith has very well described in the above blog, the dynamics, trends and effects of arctic ice are far more complicated than that and can impact ocean currents, local and global climates.
I’ll ignore the WUWT comment and thanks for the ENSO tip.
NOAA Climate Prediction Center
source: http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/index.shtml
In concurrence with the observed evolution, nearly all of the ENSO models predict La Niña to weaken further in the coming months (Fig. 6). While the majority of models predict a return to ENSO-neutral by May-June-July 2011 (three month average in the Nino-3.4 index between –0.5oC and +0.5C), there continues to be large uncertainty in the status of ENSO through the Northern Hemisphere summer and fall. Due to both model and observed trends, there is increasing confidence in ENSO-neutral conditions by June 2011. However, model forecasts issued in the spring typically have minimum skill (the “spring barrier”), which results in low confidence forecasts for summer and beyond.
So, how does a return to ENSO Neutral in 2011 relate to 2007?
I’d be more inclined to look at salinity levels at the Bering Strait this summer which accounted for over 50% of the 2007 Arctic Ice melt. My guess would be lower to normal salinity in 2011 but we’ll see.
ENSO typically weakens into the northern hemisphere summer. Nothing unexpected about that – see this discussion by Claus Wolter – http://www.esrl.noaa.gov/psd/people/klaus.wolter/MEI/#discussion
The SOI remains very, very strongly positive. I’m with Claus Wolter – I’d put odds on a La Nina reforming later in the year.
Have you seen the following global temperature trend chart for the last 11 years?
http://bit.ly/eCmQ4S
It is not 0.2 deg C per decade.
It is not 0.1 deg C per decade.
The moment of truth is approaching!
Place your money and take your pic.
http://www.woodfortrees.org/plot/uah/from:2001/trend:0.75
How about showing BOTH charts together, without the linear trend, as this:
http://www.woodfortrees.org/plot/hadcrut3vgl/from:2001/plot/uah/from:2001
It isn’t misleading about trends up or down, nor makes the scales so small (0.05 or 0.1 degrees) that the slopes looks dramatic.
Both look fairly flat overall, the HADCRUT data does trend down slightly, where the UAH trends slightly up.
The MAIN question is, where will the plots show 1 year, 3 years, 5 years from now (fyi if I were to make a guess, I would say lower based on solar activity, along with shifts in the ocean cycles . . ).
Huh
11 years?
http://www.woodfortrees.org/plot/hadcrut3vgl/from:1750/plot/gistemp/from:1750/plot/hadsst2sh/from:1750
What’s 11 years?
If you know you have a strong 50-80 period cycle influencing your trend, what could possibly induce in you the irrational notion that 11 years means anything at all, predicts anything at all, or represents anything at all?
Wouldn’t you want at least enough periods and enough analyses to establish some sort of statistical and graphical confidence?
Why, when you have over a dozen times that little tiny puny insignificant eleven year speck to work with would you restrict yourself to such a limited and unreliable span?
You’re right Bart, I was mostly making the point about the ‘trendline’ vs. actual data, and comparing them (wasn’t focused on the length, just used the same lengths as Girma and Iceberg).
I should have said the same thing, why not look at varying lengths of times, rather than just the last several years (I accept that ‘criticism). As far as signficant lengths, that will always be a debate of ‘what is long enough’ when it comes to what ocean and solar cycle lengths are. And knowing where things were before the latest cycles. That’s fine too.
BartR
You are right.
The long-term temperature record you posted is what counts.
It is irrational to concentrate on 11 year periods (or 30 year periods for that matter).
If we look at the long-term record we see a rough sine curve with a total cycle time of around 60 years and an amplitude of +/- 0.2C on a tilted axis with an overall warming trend of 0.04C per decade.
If we compare this with the CO2 curve, we see no statistical correlation, CO2 increases gradually at first (based on ice core data) and then at a CAGR of around 0.4% per year since Mauna Loa measurements were installed in 1958.
The three statistically indistinguishable observed warming cycles occurred in the late 19th century (essentially no human CO2), the early 20th century (very little human CO2) and the late 20th century (large increase in CO2). In between there were cycles of slight cooling (also with no correlation with human CO2).
That’s the record that tells us something.
Not 11-year or 30-year “blips” in the record.
Max
This chart shows how CO2 and temperature correlate.
http://farm6.static.flickr.com/5270/5551986903_f7068323cc_b.jpg
The correlation is good for the past 30 years or so, but that’s it. Otherwise there is no statistically robust correlation between measured atmospheric CO2 and measured global temperature.
This is a dilemma for proponents of the dangerous AGW premise, since it points to multi-decadal cyclical factors rather than human GHGs as the primary drivers of our climate.
Max
Max
Your logic is sound.
For the case of first order relations on homogeneous materials with no large noise, I’d be in absolute agreement.
Which is not the case here.
As it is, I’m skeptical both ways.
I doubt there is enough good information contained in simple graphs to accurately draw conclusions about the relationship between CO2 and temperature.
I also equally dismiss analyses casting doubt on more complex and complete bodies of knowledge using only the limited information in such graphs.
The one line on the graph, the rising CO2 level, itself seems to me adequate in and of itself to act upon.
Why do we need to know what harm it does, when we know it is change forced on each of us without consent to our shared common, and as the rising nature of that curve in itself proves, limited resource?
There’s a CO2 budget ceiling.
It’s being exceeded.
CO2 emission is overgrazed.
The many equal co-owners are not compensated by the few free riders who profit or waste most.
The scientific question of what drives climate and how, I remain open to.
The human equation of what is each of ours to defend and what is not ours to take more than our share each without paying, this one we can decide on with what we know now.
Bart R,
You actually do not know
1- what the CO2 budget is
2- if we are over that budget.
3- over razing is a poor choice from a person who revels in finding that correct word.
But thinking on over grazing, the disruption of the world corn markets at the inspiration of the AGW community is in fact hurting a lot of people outside of the small numbers of farmers and ethanol profiteers. Is it time to call a halt to the disruption of our food supply for tax subsidized fuel profits?
hunter
1-I say we don’t need to know what ‘the’ CO2 budget* is.
At least I don’t need to know; I’m comfortable with sufficient information to decide to act, and don’t require extraneous detail.
If the federal debt is increasing in both absolute and relative terms and the economy is shrinking, then we know deficit spending is also happening and is a problem, regardless of what else we know about the debt or the deficit.
2-The same applies to the CO2 budget. If there is increasing CO2 then the photosynthesis debt is increasing. That means there’s a photosynthesis deficit.
As we’re not overall increasing our photosynthesis globally in any meaningful way, and indeed likely are decreasing it, we know we’re in trouble by over-emitting GHG’s.
3-overgrazing is the apt term. It harkens to the origins of the term ‘tragedy of the commons’, as a common pasture will be overgrazed by indigent drovers’ herds.
We don’t need for a government to go as bankrupt as California to know it spends too much.
We don’t need to get to the point the cAGWers dance around pointing and singing ‘toldja so’ to know we emit too much GHG.
I have no doubt that many greenies were duped by ADM and its cronies into thinking that burning biomass was somehow good for something.
Not all greenies are skeptics, and some are remarkably naive and are even as math-challenged as congressmen.
It was never time for there to be tax-subsidized fuel, especially of the ethanol variety, and so I agree, past time to halt those subsidies.
*Budgets?
The one that is determined by photosynthesis, we’re clearly past.
The one determined by shifts in soil microbe and wild plant populations?
Also we’re well into the ceilings of those.
What budget ceilings we’ll top before we hit 800 ppmv, when many high-value commercial species seedlings will fail and those species become extinct, I don’t know.
Is 800 ppmv even a possible level to reach, I don’t know.
Where do you see us stopping, and how?
Iceberg, Martin C, Bart R, Manacker
Which interpretation do you support? Why?
Accelerated warming of the IPCC: http://bit.ly/b9eKXz
Cyclic warming and cooling of Skeptics: http://bit.ly/cO94in
Girma
Between the two choices you propose, I support neither, but with a set of distinctions:
1. There is slightly too little data to hold the accelerated warming hypothesis to be true, so far as I know, at this time, and it is possible that with rapidly changing circumstances we may never be in a position to fully accept to a high confidence level such a conclusion.
2. I’m a skeptic, but I find nothing skeptical in the cyclic proposal you present.
It mashes a convolution of sine curve and linear trend line up against data with no real periodicity, merely ergodic happenstance.
Were the ocean gyres truly fully periodic, there might be some mechanical basis to lend credence to this cyclic hypothesis.
As it is, that we know the multidecadal oscillations are not truly periodic (ie with fixed length between peaks), we know that any sinus curve fitting is inappropriate and that some such curves will for short spans appeal to the eye.
Your pericyclic trompe l’oeil technique is convincing artistry, not scientific confidence, a game of persuasive tricks.
If I were teaching a first course in graphical analysis, I’d almost certainly introduce the two images you present as a way of distinguishing the critical thinkers from the credulously naive among the students.
The critical thinkers might note that the first graph uses only data from real past years, while the fraudulent conveyance must first cut off early data and then extrapolate a supposed and baseless future to carry off its deception.
Those who’d read to chapter 4 in standard graphical methods texts would recognize that legitimate curve smoothing techniques are applied in the first graph, while the second flies boldly in the face of the experience and reason of the body of graphical methods knowledge by abandoning or ignoring useful and productive interpretive steps for mistakes known to generally lead to erroneous conclusions.
Were I employing analysts and saw the second presented to me by one of them, I’d toss him out of my establishment with greatest haste.
I’d have tea with one promoting the first graph and encourage him to return when he completed his work.
Bart R,
Your ability to project and fib is amazing.
hunter
Nice drive-by. Thanks for stopping in.
Bart R
Evidence 1 for “periodicity”:
Several independent studies find evidence for just two full PDO cycles in the past century: “cool” PDO regimes prevailed from 1890–1924 and again from 1947–1976, while “warm” PDO regimes dominated from 1925–1946 and from 1977 through (at least) the mid-1990’s.
http://bit.ly/gFDV5e
Evidence 2 for “periodicity”: power spectra
http://bit.ly/ghvtRx
Evidence 3 for “periodicity”: detrended global mean temperature
http://bit.ly/ePQnJj
Girma
Do you understand the difference between periodic and ergodic?
Periodic must have a fixed and invariate period. The same distance between peaks, the quality that like points in time are characterized by like tangents to the curve invariably. When you say ‘periodic from 50-70’ either you are saying you do not know the actual period but estimate it to be 60+/-10, or that what you have is _not_ periodic.
Ergodic is what we do have. Sometimes the peaks may be 50 or so years apart. Sometimes 70 years or more will happen between peaks. This is not a subtle or unimportant distinction.
Imposing an actual periodic curve — especially one that requires the amount of manipulation as you apply to your slanting sine line — on a couple of cycles of an ergodic pattern may please the eye, it is always possible to do, but it is never a valid graphical method.
Within a few further periods the resemblance of the actual ergodic and the hypothesied periodic curves will fail, because there is no real mechanical connection between the hypothesis and the actual.
How can you not know this basic truth of graphical methods?
Please be more specific.
Girma
Surely when data from 1840 is available, starting in 1880 is suspect of cutting off early data.
Surely when it is 2011, a plot to 2100 uses imaginary dates.
The suggestion of fit is produced by lying to the eye.
These are invalid and fraudulent methods.
POINT 1
Surely when data from 1840 is available, starting in 1880 is suspect of cutting off early data.
Temperature data for the period 1860-1880 are more uncertain, because of sparser coverage, than for later periods in the 20th Century.
http://bbc.in/aneJgx
POINT 2
Surely when it is 2011, a plot to 2100 uses imaginary dates.
http://bit.ly/emAwAu
The above chart shows the following periods for relative global cooling and warming phases:
1.30-years of global cooling from 1880 to 1910
2.30-years of global warming from 1910 to 1940
3.30-years of global cooling from 1940 to 1970
4.30-years of global warming from 1970 to 2000
This pattern was valid for 120 years. As a result, it is reasonable to predict it will also be valid at least for the next 30 years.
(Which model predicts the current global mean temperature plateau? The cyclic model or IPCC’s accelerated warming?)
POINT 3
The suggestion of fit is produced by lying to the eye.
Here is the high correlation (r=0.88) between my model and global mean temperature.
http://bit.ly/eYJZAU
POINT 4
These are invalid and fraudulent methods.
I thought the above label instead apply to the following:
The scientific community would come down on me in no uncertain terms if I said the world had cooled from 1998. OK it has but it is only 7 years of data and it isn’t statistically significant.
http://bit.ly/6qYf9a
That was no warming for 7 years.
Now, it is no warming for 13 years.!
http://bit.ly/fMwWl1
Why there is no comment from the “scientific community” regarding this truth?
Girma
POINT 1 – there are valid methods for dealing with the issue of less reliable data graphically, for example error bars and variations of the same.
POINT 2 – You compare apples and sheep. It’s never reasonable to base predictions on invalid methods, and so far as one can tell your method is, “Girma sees what Girma wants to see.”
POINT 3 – Sir, has not your correlation been already compared to other curves with better correlation? The illusion of correlation is not demonstration of causation, and is in particular not disproof of a signal within noise.
I’ve seen sine curves imposed on ‘movements of history’ and the fortunes of businesses, family planning and lightning strike patterns, lottery winners and distribution of cavities among grade schoolers.
You can always force some sine curve to fit a curve for a short span, even of random data.
If you don’t have an actual periodic mechanism with a truly fixed and invariate period, then applying a sine curve to your data will mislead the casual and uneducated observer.
It’s just fraud.
POINT 4 – And there might be ‘no warming’ of this type for another seventy years, but still AGW might be true. We’re at a virtual plateau at the highest global temperature level we know of or can reasonably guess at in millennia.
If we hold at this level for the next 17 years, then we will continue to have an increasing 30 year average.
If the next half century after that remained at the same plateau, we’ll have a century of radical change due temperature alone, separate and apart from all the other effects of CO2.
Do I predict such?
About temperature, I predict nothing.
About CO2, the matters are much clearer, and we know it is increasing due to our actions, creating a lasting debt against the CO2 budget of our air, due our CO2 deficit spending.
Apply your graphical methods to CO2.
Temperature graphs are the playground of speculation and confidence games.
I love it when he speaks French – but I suggest that trompe la monde is more the case here than trompe l’oeil.
My fear is that both sides are wrong and that what we have here is a true case of dynamical complexity. I doubt that either causality or periodicity apply in a strict sense. I tremble that climate states are both non-stationary and non-Gaussian. I am in trepidation that climate, like Quantum Mechanics, can only be understood in the realm of the poetical.
I can only suggest that you wrestle with the concept of canonical uncertainty – chaos theory in other words. It is the sound of continents colliding and mountains rising . Kaboom. The surf pounding. Kaboom. Of tremendous energies cascading through powerful systems. Kaboom. Of lashing rain and cracking thunder. Kaboom. Of ice cracking and crashing into the sea. Kaboom.
We are on a journey of imagination and understanding barely begun and yet most everyone seems content that they have leapt to the end. I don’t mean to be rude but all our sound and fury is only a faint echo of the complexity, immensity and majesty of the world.
After the demonstrable success of “nuclear physics” during WWII, the science was riding high. Enormous sums were expended building ever larger accelerators to reach the true understanding of what drives the engines of creation. Even though many useful and interesting discoveries have been made along the way, what we have really discovered is how little we really know about how it all really works. I suspect that climate science is in the same boat. The Uncertainty Principle may be the unrecognized 800 pound poet waiting in the climate science living room. The most dramatic Kabooms in the universe are all macroscopic manifestations of microscopic events.
Yes – a true hero and saviour of humanity – the 800 lb poet.
Chief
And to think that just this morning I was worried that if you got any more Australian, you’d turn French.
Girma,
I am a firm skeptic of AGW. From all I have tried to learn, CO2 probably has some small effects to temp increase, outweighed by solar and ocean cycles (and maybe the ocean cycles are in part driven by solar activity . . .). So I am on the ‘cyclic warming and cooling from the noted cycles’ side of thigns.
My comment was about the data set and trend lines give different results in their appearance (your first plot, followed by Iceberg’s plot, different data set, different looking results, especially with the scales the way they come up on the plots). Showing the data makes more sense to me than just a trend line ( that’s just how I like to see it), whether it is several years, or longer number of years. And seeing several plots of varying length are good to, to get a broader picture. That’s the point I was trying to make. Not trying to pick on anyone (sorry if that’s how it may have appeared).
Girma
I definitely do NOT support the first graph. This was a classical IPCC smoke and mirrors story, comparing shorter term periods with longer term ones in an attempt to show an acceleration. One could have started the curve at 1906 (IPCC’s start of the 20th century) and drawn a shorter trend line for the first 40 years and another longer one for the entire century. This curve would have shown that the warming is apparently decelerating instead of speeding up. But it would have been a lie, just like the IPCC curve. (There has been neither an acceleration nor a deceleration, in actual fact.)
The second curve gives a much better approximation of what the record is showing us (as you showed earlier with your detrended Wood For Trees chart), namely a temperature record with multi-decadal warming and cooling cycles resembling a sine curve with a total cycle time of around 60 years and an amplitude of +/- 0.2C all on a tilted axis with a gradual warming trend of 0.04C per decade.
The idea of a cyclical record (as we undoubtedly observe here) is an anathema to dangerous AGW believers, as it shows that natural factors are playing the overriding role rather than human GHG emissions, so many deny it and others simply ignore that it exists.
Max
Girma
Here’s that curve demonstrating a “deceleration” in the rate of warming over the 20th century (it’s a sham, like the IPCC curve showing the opposite)
http://www.woodfortrees.org/plot/hadcrut3vgl/from:1906/to:2005/plot/hadcrut3vgl/from:1906/to:1945/trend/plot/hadcrut3vgl/from:1906/to:2005/trend
Max
manacker
I cannot wait to see how the back down from AGW is going to look like.
Girma
Look for “rampant ocean acidification threatens survival of coral reefs”.
Or maybe something totally new like “scientists link rampant increase in growth of crop-killing weeds to higher CO2 levels”.
With a good imagination, the possibilities are unlimited!
Max
Judith points out that there are many factors that affect Arctic sea ice extent beside global temperatures (ocean currents, winds, etc.). In fact, global temperature really does not have much impact locally anywhere.
How about local temperature?
There is a good long-term record of temperature at Illulissat (near the mouth of the Jacobshavn Glacier in Greenland, which appears to be receding today).
I have gone through this record to arrive at monthly and annual averages, which I have then plotted against time (since 1900). The record only went to 2005 when I did this.
http://farm3.static.flickr.com/2620/3797223161_16c1ac5e39_b.jpg
The record shows some unexpected results:
First, it shows that it has cooled very slightly overall from 1900 to 2005, although this cooling is statistically insignificant.
Over the first half of the century (1900-1950) there was significant warming of 2.3°C (this is confirmed by the Chylek et al. findings of early 20th century warming in Greenland), while the second half (1951-2005) showed slight cooling of 0.4°C. Since around 1980 there has again been a warming trend. This latest trend covers the same period of Arctic sea ice retreat, as measured by satellites.
What this all tells me (at least for Illulissat, Greenland) is that tghere have been warming/cooling cycles in the past, and that the current warming is nothing unusual.
Max
any ideas why there was what seemed to be that abrupt change around 1950? At first glance, you would say that these are 2 different sets of data.
Is the Arctic ice extent today at an unprecedented low?
Here is a study that concludes otherwise:
http://www.agu.org/pubs/crossref/2006/2005JD006494.shtml
Max
Max
Can you confirm.. did this study calibrate against tree ring proxies?
What is their confidence level?
Do they mean that a 170 year period exceeded the multidecadal ice loss of a 10 year period?
In other words, the 1990s had as high as sixteen times as much multidecadal ice loss as the warmest other time period this study could find?
Please disambiguate.
The article does not compare current ice, but instead the ice 11-21 years ago ! i.e the 90’s.
It says nothing about whether the recent summer ice, which is considerably lower than the 90’s is unprecedented or not. (and this is assuming the study is right and also assumes the this one area of ice can represent the entire arctic ice range.), both of which are substantial assumptions.
Here is yet another study (co-authored by Polyak) showing that the current Arctic sea ice retreat is not unusual.
http://bprc.osu.edu/geo/publications/mckay_etal_CJES_08.pdf
Max
A Regional Summary report for the Arctic (on the Global Warming web site written by Alan Cheetham) provides a wealth of data related to Arctic temperatures, sea ice extent of the past, etc.
This includes a comparison of surface air temperature anomalies in the Arctic with global values since 1875, which shows much stronger early 20th century warming in the Arctic, followed by a long decline until around 1970, when the current warming started.
http://www.appinsys.com/GlobalWarming/RS_Arctic.htm
(At the same time Antarctic temperatures have remained constant since 1979.)
The report cites a study by B.U. Hansen et al., which concludes:
There are several other studies cited and linked on this site. In general, they show that there is nothing unusual about either the current Arctic temperatures or the Arctic sea ice extent, when compared to the past record.
Max
Here is an analysis of the Polyakov data on Arctic temperatures since 1875.
http://farm4.static.flickr.com/3175/2851297269_77757a7cd4_b.jpg
This shows much stronger warming and cooling cycles than the global record. So what is causing these?
Max
Here is a link to a pdf of the Polyakov et al. study
http://journals.ametsoc.org/doi/pdf/10.1175/1520-0442%282003%29016%3C2067%3AVATOAT%3E2.0.CO%3B2
Here is a final link to a study by Smolyanitsky et al. entitled: “Arctic climate variability: 60-year cycles and their consequences”:
ftp://ftp.whoi.edu/pub/users/mtimmermans/ArcticSymposiumTalks/Smolyanitsky.pdf
This study shows that Arctic sea ice has increased/decreased since 1900 in multi-decadal (60-year) cycles, following a sine curve pattern, with a similar trend for Arctic temperature.
The authors conclude:
And
Max
as always the thought creeps in…what if this is cargo-cult science?…. every 30 years something happens to get things back in equilibrium. Do we know? Or are we like Girma, just hoping that historical trends recur?
Graeme
It is not just a hope. That is also what the power spectra shows.
http://bit.ly/ghvtRx
Graeme
You ask: “Do we know” [what causes the observed multi-decadal cycles in our global temperature as well as – even more strongly – the Arctic temperature]?
Girma has shown one possible connection. I have seen others relating to ocean circulation oscillations (PDO , ENSO, etc.).
I do not believe that we really do know.
But we know for fairly sure that AGW from human CO2 emissions is not playing a primary role here, because the correlation between atmospheric CO2 and temperature is basically a random walk, with no statistically robust correlation, ergo a very poor case for causation.
I do believe that if climate science spent more research time on solving the uncertainties concerning the impact of natural variability (a.k.a. natural forcing) on our planet’s climate rather than myopically fixating on the AGW story, we would soon have some answers to your question.
What do you think?
Max
Graeme and Girma
Smolyanitsky et al. have suggested an explanation for the observed cyclical temperature record in the Arctic, which would also explain the opposite trend observed in the Antarctic. They refer to this as “solar system dissymmetry, as a result of which fluctuations of solar constant occur”.
Does this make sense?
Max
manacker
I agree with you that it makes sense to try to understand how the system works as a whole before leaping to any conclusions. I am reminded of technical analysis of stocks and shares where the chartists claim to discern patterns in share price movements and use those patterns as the basis of trading. Sometimes they make money but I would imagine that they lose most of the time – at least that is what all the analayses of professional stock-picking suggests. sometimes, as investors like Warren Buffet has shown, you have to understand what is actually happening in the companies concerned.
I would be happier if we could really demonstrate what lies behind these apparent 30 year cycles rather than just hope that they will continue happening. at the same time, it makes sense to stop befouling the planet. however, it makes no sense to cut back on CO2 emissions in the hope that that will make a difference, simply because it undoes all the progress we have achieved as a result of industtrialisation in terms of improved health and welfare etc etc.
Graeme
You wrote:
“I would be happier if we could really demonstrate what lies behind these apparent 30 year cycles rather than just hope that they will continue happening.”
Me too.
And that is where I believe climate science should spend more time and effort, since it is the largest “uncertainty” today.
The “consensus” view today, however, is that there are no significant cycles and AGW is driving our climate, so this needs to change.
The cause and impact of the observed multi-decadal cycles should be investigated more closely, even if this work ends up falsifying the current “consensus” notion of a climate being driven primarily by human GHG emissions.
But will it happen?
Maybe Judith has the answer to that question.
Max
Graeme
Just one thing to add.
AGW is a multi-billion dollar business today, with all sorts of individuals, corporations, environmental advocacy groups, lobbyists, hedge fund operators, money shufflers, politicians, scientists, etc. ready to gain a piece of the pie (money, power, influence, funding, etc.).
This gigantic business is wholly dependent on the paradigm a) that humans are essentially driving our planet’s climate through AGW and b) that this represents a serious potential threat unless corrective action is taken.
Scientific studies, which falsify this paradigm by showing that natural cycles caused by an “identified and quantified mechanism X” have been the principal drivers of our past climate and are likely to continue being so, will upset a multi-billion dollar apple-cart.
Paradigm shifts never come easy, but I think it is a shame that climate science is under so much political pressure, but that’s the way it is today.
I just hope this does not block some courageous scientists from continuing to look for what causes the observed warming/cooling cycles that appear to be driving our climate, even if this work falsifies the paradigm that is the basis for the multi-billion dollar AGW business.
Max
‘That said there is a LOT of nonsense about the PDO. People like CPC are tracking PDO on a monthly basis but it is highly correlated with ENSO. Most of what they are seeing is the change in ENSO not real PDO. It surely isn’t decadal. The PDO is already reversing with the switch to El Nino.’ K Trenberth – hacked email
Trenberth is certainly wrong. The biology is definitive – as in the fantastic Russian fisheries publication someone linked to earlier. I can’t recommend it enough. The biological changes occur as a result of changes in upwelling of nutrient rich water. But the evidence of decadal changes in hydrology, cloud and sea surface temperature is equally compelling. As sure as sh.. – as we say in Australia (I have censored myself for sake of Bart’s delicate sensibilities – and the fact that I keep getting sent, albeit temporarily, to the sin bin) – it is decadal.
The changes have been attributed to solar UV in the 11 years Schwabe, the 22 year Hale and other diverse solar cycles – which drifts much more over longer timeframes than does solar irradiance. – See for instance – http://iopscience.iop.org/1748-9326/5/3/034008/fulltext – See also – http://iopscience.iop.org/1748-9326/5/2/024001/fulltext
The mechanism involves warming and cooling of ozone in the middle atmosphere – which influences sea level pressure at the poles and thus the path of storms spinning off the polar vortices.
The correlation between ENSO, the Southern Annular Mode (SAM) and solar cycles has been shown in many studies. In the Southern Hemisphere – increased SLP in higher latitudes pushes storms and cold Southern Ocean water towards the western coast of South America in the region of the Humboldt Current. The Humboldt Current is the thermal origin of ENSO and ENSO is of course is the dominant source of global climate variability.
I usually add the postscript that dynamical systems theory implies extreme climate sensitivity near points of chaotic bifurcation – suggesting that changing the composition of the atmosphere may not be entirely risk free.
According to Tisdale, PDO is an index or pattern of Sea Surface Anomalies in a defined area of the North Pacific. The swings in the pattern are multi-decadal. There are lots of references and links in the following (and even a correction to a previous Tisdale conclusion).
Tisdale, Bob. 2009. Misunderstandings about the PDO – Revised. Scientific Blog. Climate Observations. April 27. http://bobtisdale.blogspot.com/2009/04/misunderstandings-about-pdo-revised.html
Yes, but the question is, does the PDO result in changes to cloud cover which materially affect albedo?
The PDO was mentioned by Trenberth – but which comes first PDO and ENSO decadal changes? I think it all evolves out of upwelling in the Humboldt Current with feedbacks on trade winds. The cool water moving westward across the central Pacific strengthens Walker Circulation and therefore trade winds – south easterly in the Southern Hemisphere and north easterly in the Northern Hemisphere. A positive feedback for upwelling in the eastern Pacific – both north and south of the equator.
There are of course surface observations of decadal cloud changes in the Pacific north east and south east and satellite observations of tropical radiative flux showing decadal cloud change.
Looking at metro below – black carbon is a developing world issue. We could help quite cheaply and save millions of lives – but that is not what the greens are about is it.
I read that PDO is a multi-decadal index of ENSO changes. If so, ENSO would precede PDO changes.
Dr Curry:
I don’t think you mention black carbon here, although one of the responses does, just in passing , almost .
Why is the research by Drew Shindell of NASA and others, paid so little attention?
He concluded —
that ‘black carbon is responsible for 50% or almost 1degreeC increased Arctic warming from 1890 to 2007’, and that ‘the climate-warming effects of these short-lived pollutants have largely been ignored by scientists and regulators focusing on climate policy’
and—
“We will have very little leverage over climate in the next couple of decades if we’re just looking at carbon dioxide,” Shindell said. “If we want to try to stop the Arctic summer sea ice from melting completely over the next few decades, we’re much better off looking at aerosols and ozone.”
If climate scientists actually wanted to slow down the Arctic melt, and the knock-on effects from that, why would they not be lobbying governments, and mobilising the general population to do likewise, by making sure they make the point prominently and strongly in every article they write on the subject of Arctic warming?
The opposite is true—it’s hardly ever mentioned.
I know a few scientists are lobbying the US government on this, but they get almost no publicity or support from other scientists , to back them up.
I don’t know why anything is written about the problem if this large aspect of it is not even paid lip service most of the time.
Is it not worthwhile to mitigate 50% of the Arctic warming?