by Judith Curry
“Climate dice”, describing the chance of unusually warm or cool seasons relative to climatology, have become progressively “loaded” in the past 30 years, coincident with rapid global warming. The distribution of seasonal mean temperature anomalies has shifted toward higher temperatures and the range of anomalies has increased.
Jim Hansen et al. have posted a new draft paper entitled: Perceptions of climate change: the new climate dice.
This text summarizes their approach:
We use the Goddard Institute for Space Studies (GISS) surface air temperature analysis to examine seasonal mean temperature variability and how that variability has changed in recent decades.
We illustrate observed variability of seasonal mean surface air temperature emphasizing the standard deviation (“bell curve”), which the lay public may appreciate. We choose 1951-1980 as the base period for most of our illustrations, because that is a time of little global temperature trend just prior to the rapid global warming in recent decades. It is a period that older people today, particularly those of the “baby boom” generation, can remember. Global temperature in 1951-1980 is also within the Holocene temperature range, and thus it is a climate that the natural world and civilization is adapted to. In contrast, global temperature in the first decade of the 21st century is probably already outside the Holocene range, as evidenced by the fact that the Greenland and Antarctic ice sheets are losing mass rapidly and sea level is now rising at a rate (3 m/millennium). (see the manuscript for reference citations).
JC comment: I like the general approach used in this study. However, the last sentence about the Holocene threw me for a loop. Even accepting the statements about Antarctic ice sheets and sea level rise at face value, how does this evidence lead to a conclusion that global temperature in the first decade of the 21st century is probably already outside the Holocene range? I agree that the ‘detection’ problem should be framed in the context of climate variability over the entire Holocene, but I have not seen anyone do that convincingly.
The results are clearly and simply presented. Maps of spatial variability of anomalies, as well as global averages are presented, mostly on a decade by decade basis.
“Loading” of the “climate dice” describes the systematic shift of the frequency distribution of temperature anomalies. Hansen et al. (2) represented the climate of 1951-1980 by colored dice with two sides colored red for “hot”, two sides blue for “cold”, and two sides white for near average temperatures. With a normal distribution of temperatures the dividing point would be at 0.43σ to achieve equal (one third) chances of being in each of these three categories in the period of climatology (1951-1980).
Fig. 5 confirms that the global occurrence of “hot” anomalies (seasonal mean temperature anomaly exceeding +0.43σ) has approximately reached the level of 67% required to make four sides of the dice red, with the odds of either an unusually “cool” season or an “average” season now each approximately corresponding to one side of the six-sided dice. However, the loading of the dice over land area in summer is even stronger (Fig. 5, lower row).
Probably the most important change is the emergence of a new category of “extremely hot” summers, more than 3σ warmer than climatology. For practical purposes it is important to look at the changes over land areas, where most people live, rather than the global mean for which anomalies are more constrained by the ocean’s thermal inertia. Fig. 6 illustrates that +3σ anomalies practically did not exist in the period of climatology (1951-1980), but in the past several years these extreme anomalies have covered of the order of 10% of the land area.
The study also focuses on the U.S., back to 1900, to compare recent temperatures with those in the 1930’s.
Nevertheless, it is apparent that the long-term trend toward hot summers is not as pronounced in the United States as it is in hemispheric land as a whole. Also note that the extreme summer heat of the 1930s, especially 1934 and 1936, is comparable to the most extreme recent years.
Year-to-year variability, which is mainly unforced weather variability, is so large for an area the size of the United States that it is perhaps unessential to find an “explanation” for either the large 1930s anomalies or the relatively slow upturn in hot anomalies during the past few decades. However, this matter warrants discussion, because, if the absence of a stronger warming in recent years is a statistical fluke, the United States may have in store a relatively rapid trend toward more extreme anomalies.
Some researchers have suggested that the high summer temperatures and drought in the United States in the 1930s can be accounted for by sea surface temperature patterns plus natural variability (10, 11). Other researchers (12-14), have presented evidence that agricultural changes and crop failure in the 1930s contributed to changed surface albedo, aerosol (dust) production, high temperatures, and drying conditions. Furthermore, both empirical evidence and climate simulations (14, 15) indicate that agricultural irrigation has a significant regional cooling effect. Thus increasing amounts of irrigation over the second half of the 20th century may have contributed a summer cooling tendency in the United States that partially offset greenhouse warming. Such regionally-varying effects may be partly responsible for differences between observed regional temperature trends and the global trend.
From the concluding discussion:
Seasonal-mean temperatures have changed dramatically in the past three decades. The global shift of the probability distribution for seasonal mean temperature anomalies is more than one standard deviation and the shift is even larger for land areas. In addition, there is a broadening of the probability distribution, the warming shift being greater at the high temperature tail of the distribution than at the low temperature tail.
Seasonal-mean temperatures in the category defined as “cold” in 1951-1980 climatology (mean temperature below -0.43σ), which occurred about one-third of the time in 1951-1980, still occur with a probability about 10% over land areas. Thus an occasional unusually cool winter is not evidence against global warming. Temperature is less “noisy” in the summer than winter. The chance of summer falling in the “hot” category of 1951-1980 is now about 80% (Fig. 7). The climate dice are now loaded to a degree that the perceptive person (old enough to remember the climate of 1951-1980) should recognize the existence of climate change.
The most important change of the climate dice is the appearance of a new category of extremely hot summer anomalies, with mean temperature at least three standard deviations greater than climatology. These extreme temperatures were practically absent in the period of climatology, covering only a few tenths of one percent of the land area, but they have occurred over about 10% of land area in recent years. The increased frequency of these extreme anomalies, by more than an order of magnitude, implies that we can say with a high degree of confidence that events such as the extreme summer heat in the Moscow region in 2010 and Texas in 2011 were a consequence of global warming. Rahmstorf and Coumou (23), using a more elegant mathematical analysis, reached a similar conclusion for the Moscow anomaly.
It is not uncommon for meteorologists to reject global warming as a cause of these extreme events, offering instead a meteorological explanation. For example, it is said that the Moscow heat wave was caused by an atmospheric “blocking” situation, or the Texas heat wave was caused by La Nina ocean temperature patterns. Certainly the locations of the extreme anomalies in any given case are related to specific weather patterns. However, blocking patterns and La Ninas have always been common, yet the large areas of extreme warming have come into existence only with large global warming. Today’s extreme anomalies occur because of simultaneous contributions of specific weather patterns and global warming.
JC conclusion: I like several aspects of this paper. It puts longer term climate change into context of year to year natural variability (both globally and regionally). The analysis is straightforward and clearly presented. The writing is accessible to a general audience.
The problem that I have with the paper is that the analysis does not support some of the inferences. The major conclusion (stated in the abstract) is:
We conclude that extreme heat waves, such as that in Texas and Oklahoma in 2011 and Moscow in 2010, were “caused” by global warming, because their likelihood was negligible prior to the recent rapid global warming.
First, an anomalously warm season may not correlate with the existence of an extreme heat wave. The study did not systematically consider all major heat waves during the period (they only mentioned the 2010 and 2011 heat waves), and assess whether these were predominantly associated with anomalously warm seasons.
Second, the paper concluded from an analysis of U.S. temperatures in the 1930’s that “Also note that the extreme summer heat of the 1930s, especially 1934 and 1936, is comparable to the most extreme recent years.”
A critical issue IMO is interpretation of the variability in context of the major multidecadal ocean oscillations, e.g. AMO and PDO. The paper implicitly assumes that all of the warming since 1980 is AGW (whereas even the IPCC only says “most”, implying >50%). These modes of atmospheric and oceanic circulation are more likely to be associated with the blocking patterns that produce heat waves (this was particularly the case for the Moscow heat wave).
IMO, if Hansen wants to draw this conclusion, the following analysis needs to be done. Go through the temperature data records since 1900, and search out the individual heat wave events. I would define heat waves in the context of two different definitions: 1) relative to the average local temperature for the entire period; 2) relative to the average local temperature for the decade. The combination of these allows interpretation of what is associated with the trend, vs interannual/decadal variability. Interpret the statistics globally and regionally, in the context of known modes of internal variability (e.g. ENSO, AMO) and the global warming trend. Then we would have the basis for assessing whether their conclusion is true or not.
Despite all efforts to deny reality, Earth is a tiny piece of fly ash heated by the nuclear furnace that made our elements and spit out the ash five billion years (5 Gyr) ago.
Message to Gaia: I’m truly sorry about this.
It’s all my stupid fault. I know I was warned – but I accidentally printed off an email yesterday without “thinking about the environment”.
And last week I flew long-haul to see family. I know, I know, I know that long-haul flight is only OK for climate conferences but I am just a weak person. Mea culpa.
“Climate dice”, describing the chance of unusually warm or cool seasons relative to climatology, have become progressively “loaded” in the past 30 years, coincident with rapid global warming.”
And yet out of the above-referenced 30 year time span, going on half have had no warming at all. Laughable.
They used the GISS surface data, which shows warming over the entire period. You are probably thinking about the HadCRU data.
Isn’t giss data just hadcru data that’s had more massaging?
Just referring of warmings / coolings as ”GLOBAL” is a loaded comment, by everybody. On 99,9999% of the surface area the temperature is not monitored. 2] on the earth, the distribution of heat is 3 dimensional, not like on the moon!.3] the hottest minute of the day taken is not on same minute of every day. 4] if is taken say… at 1PM Greenwich time simultaneously on every monitoring place – would be only 2 light years away from the truth, than collecting data of the hottest minute of the day, which is 10 light years away from the truth / honest monitoring.
5] some days starts getting warmer in the morning and stays warm for most of the day – on other days, it goes very high temp for 15minutes between the clouds cover; but the rest of the day is colder. What kind of science will overlook those important factors?! please, don’t tell me, tell yourself. Saying that; one month / year is warmer planet than another – is same as saying that: the planet is warmer at lunch time by 12C degrees, than before sunrise…? Com-on ”FLAT EARTH BELIEVERS” !!! When are you going to learn that: if is warmer where the monitoring is = is colder on many other place!!! That’s why it confused the Swindlers; they declared warming in 98, then few years after started getting data that is getting colder. The truth: if is getting colder instead of increasing warming, is because HEAT AND COLDNESS CHANGE PLACES, not warmer and colder years. Laws of physics and my formula don’t permit warmer THE WHOLE PLANET. Same laws of physics will be in 100 years !!!!!!!
The Pacific Northwest had a very cool (if not flat-out cold!) summer in 2011. This, I belive, contributed to the heat aplification in Texas and Oklahoma. Both of these events were “natural” in origin.
They’re related. La Nina causes both cool wet weather in the PNW and hot dry weather in TX.
P.E., La Nina / El Nino are caused from moving of the tectonic plates and disturbing the ”hot vents” on the bottom of the sea. Those natural phenomena are definitely not related to the phony GLOBAL warming. In which case – you are proving that the Skeptics as me are correct, thanks.
Jim S, similar affects happens in Chile and eastern Australia, if is to the El Nino / La Nina affect.
The second version is: it’s bigger possibility the west-coast was colder BECAUSE of the extra heat in Texas. Sounds weird, doesn’t it; but is the most important phenomena. It applies to a city / state or a continent the same. I’ll explain how the big city heat island works – you can connect the similarity to Texas V west-coast: with increased people / bitumen in a city; the 500km3 of air gets warmer > that same air expands to 550km3 – that extra volume of 50km3 cannot north or west – because is already air there. The only alternative is to go up and increases the volume of the troposphere by 50km3 – up there temp is minus -90C, intercepts extra appropriate coldness in 3,5 seconds, to equalise.the extra heat in your city.
As soon as it cools – it shrinks and falls down. But, because of fast spinning of the planet eastwards – that extra coldness falls somewhere far west; plus if you include the affect of the winds to directions to that coldness falling down in changing direction and distribution; same rules applies to much larger areas. I.e. as long as is warmer > the air expands; but as soon as equalizes by cooling some other area – volume of the troposphere shrinks INSTANTLY to normal volume. Because if the volume of Texas air increased by 5%, by getting warmer’ if that 5% stayed expanded for one week after cooling some other place as west-coast – hypothetically, would have redirected enough extra coldness, to freeze all
the tropical rivers and lakes. That’s how the self regulation works; by oxygen / nitrogen shrinking / expanding in change of temp, not by CO2 and shonky climatologist. Laws of physics and my formula will win!!!
Climate dice are loaded and ignore changes in the biggest climate forcing – bright sunshine.
Using MET designation England North
# of bright sunshine hours per decade.
36% more sunshine from the 1930s (or 1970s) to the 2000s.
Bruce, some Poms are realising that ”England is not the world any-more” for others will take longer to adjust.
When is less ice on Arctic ocean; because they are demolishing it by ice crusher ships – because of those corridors, ruff water damages much more -just to get the shonky experts and bias media further north = water with less ice as insulator, absorbs extra coldness – that extra colder water travels south to Mexican gulf – from where the ”Gulf Stream” brings warmer water to England (less warmer water = less clouds; soon you will be able to grow lots of win-yards, noooo is not warmer planet, but win-yards like sunshine. If too often rain; before grapes ripe – it splits from the first rain – the second rain makes it to fungal rot. Bruce, dryer and wetter doesn’t mean warmer / colder planet. Dryer means more extreme between day and nigh temp – wetter means MILDER CLIMATE. Not for both camps climatologist; their climate is adjusted by the Fujitsu air-conditioner. That’s where the statement comes from: ”if we can keep the GLOBAL warming to 2C degrees… ? Like the button for the air-conditioner… it’s sick, isn’t it?
Also important. Don’t exclude any events. Define criteria ahead of time for what defines an event. Otherwise, the door to cherry picking is open. When he picks Texas and Moscow, it isn’t because they were the only events. It was because they make his case.
Right. The notion of “climate dice” seems a transparent attempt to claim causal relationships without having to go to the trouble of explaining the underlying mechanisms. Like “climate change,” it’s inherently unscientific because it generates unfalsifiable hypotheses.
P.E. said, “It was because they make his case.” I think he is working hard to make some case after all the predicting he did in the 1980s. He has a long way to go before the US warms 2 degrees by the end of this decade.
The text seems oddly familiar
lol. Yet another similarity between UFOology and AGW.
The hilarious part was this claim:
Surely these folks must know that an increase in warm outliers is a predictable result in a warming climate? AFAIK, GISS is still using the 1951-1980 climatology … more warm outliers? Duh, here’s your sign.
Of perhaps they don’t know that. But surely you must know that, Judith.
Or perhaps you don’t either.
But I assure you that in a warming climate, you will get more outliers at the top end of whatever you choose for your anomalies. That is an EXPECTED RESULT
Finally, Hansens analysis only makes sense if we assume that the temperature is a stationary process … but we have no such assurance.
Sorry, accidentally pushed the “Post Comment” button. To finish …
Hansen once again is hyperventilating over an expected result. He thinks the “climate dice” has changed because his climatology, like his ideas, is stuck in the 1950s.
Can’t say I’m surprised by anything Hansen does these days. The surprise is that anyone still pays attention to him.
he’s like me, he at least writes clearly and understandably, the difference is his papers don’t get rejected!
Page 9 ” Overall, global warming causes the atmosphere to hold more water vapor, thus allowing for more extreme precipitation events”
We know well that moisture content in the atmosphere has not changed with global warming. Why would Dr. Hansen say, or allowed to publish such untrue statement? Moisture content in the air near surface has increased, but moisture content in the in the atmosphere has not changed.
I tend to agree Willis. As far as I can see their only actual result is to show that the GISS dataset shows global warming, outliers and all, which is not news. The scary attribution speculation is just that. Nothing to see here folks.
I thought that satellite data showed that World and Antarctic ice was growing. Hansen is also reputed to have disagreed with other satellite data, applying corrections to it make it match his models. Odd that a space studies institute should so distrust satellites.
as discussed here previously antarctic ice areal extent is growing due to sea ice, overall antarctica is losing ice MASS both sea and land combined. somebody pls refute if i’m wrong
Bill – You are correct. GRACE and mass balance measurements indicate that Antarctica is losing ice mass despite some small rises in sea ice area during Antarctic winter.
Conflicting data would be the increasing spin rate of the earth (indicating the earth’s decreasing spin axis moment of inertia due to water mass in equatorial oceans being transferred as snow and ice to polar regions) as evidenced by the decreasing frequency that LEAP seconds are added to our official Universal Mean Time atomic clock adjustments. (Read Tom Wysmuller’s Frequently Asked Question #16 at the following link http://www.colderside.com/Colderside/F.A.Q..html to see the Leap Second data. The discussion about rate of sea level rise and predictions from his “Toucan Equations” starting with FAQ #11 is also very interesting.) The long term trend of the earth’s spin rate would be for it to slow down due to lunar tidal friction effects, so some shorter term process is speeding up the spin rate, from its normal slow decline that requires the Leap Seconds to be added to our calendar until an anomalous Leap Year full day adjustment can be made. Also I have seen Wysmuller’s video evidence of large anomalous snowfalls in the interior of Antarctica in recent years that must be adding mass to the continent compared to the normal desert climate of Antarctica.
The Earth’s spin rate is declining, not increasing. Your link doesn’t contradict that. I didn’t spend much time on the article, but it was correct in stating that the slowing of the Earth’s rotation as well as a change in the rate of slowing reflect a multiplicity of factors and can’t be attributed to any single influence.
According to nist, less leap seconds are being added now than there were before the most recent decade.
Do you have data that says we should be adding leap seconds and we are not?
The spin rate has increased, the leap second data does prove that.
Herman – You misread the article. The spin rate continues to decline. A new leap second is to be added this year.
From the NIST website: “There are two main reasons that cause leap seconds to occur. The first reason is that the atomic second was originally defined by comparing atomic clocks to the Ephemeris second, which is slightly shorter than the mean solar second and which is no longer used. This made the atomic second slightly shorter than the mean solar second to begin with. The second reason is that the rotation of Earth varies and is gradually slowing down, so the mean solar second is gradually getting longer. All of these factors contribute to the difference between UTC and UT1.”
The rate of slowing may itself be declining, but there are so many factors involved that we really can’t conclusively assign the reason to any one of them.
9 leap seconds in the 1970’s
6 leap seconds in the 1980’s
7 leap seconds in the 1990’s
2 leap seconds in the 2000’s
1 leap seconds in the 2010’s – so far
This is increasing spin rate, not declining spin rate.
Herman – Every leap second added signifies a declining spin rate, and the excerpt I quoted from the site makes that explicit. What you are referring to is a slowing in the rate of decline, but it is still a decline. Why the slowing rate is itself slowing is not easily attributed to any single factor.
You got your math wrong.
If you add 9 leap seconds in the decade of the 1970’s and you add 2 leap seconds in the decade of the 2000’s, the spin rate of earth has increased.
Herman – In addition to the NIST site, interested readers can Google “leap second” to find many other similar descriptions. All tell us that leap seconds are added because of the continued slowing of the Earth’s rotation. A temporary increase between 1999 and 2005 made that unnecessary for a short time, but the slowing has resumed, and so a leap second will be added in June 2012. If the Earth’s rotation speed increased for more than a short interval, it would be necessary to subtract leap seconds, but the addition of leap seconds, even if infrequent, signifies a slowing. You should review these various sources of information if you have doubts about this. Others can do the same, and so I will probably leave it at that.
Fred, where is possible to find out more about slowing of the spinning of the planet? That should be more important than anybody can comprehend. Because of earth’s centrifugal force, if spinning is slowing – on equatorial regions the sea-level will drop; below the parallel of Capricorn and above parallel of Cancer – the sea-level will rise – especially closer to the poles.
Surely you’ve heard all your fellow sceptics tell you how hard it is to understand climate, how its all highly non-linear, how its just so hard to be certain about anything?
But, here you are telling us
“I think that some meteorologists, engineers and scientists, outside the consensus group, should look at their theory and models. Their theory is badly flawed”
yet, you don’t seem to have understood that adding a leap second is necessary because the Earth’s rotation is slowing , rather than spinning faster.
Wouldn’t you be better off spending your retirement years doing something which isn’t quite so intellectually demanding?
The number of leap seconds tells about the difference between 86400 seconds and one solar day. The solar day is longer and the difference is growing in long term as the Earth is losing angular momentum while the motion of moon is accelerated. The frictional lag of tides is the mechanism that is transferring angular momentum from rotation of Earth to orbital motion of the moon.
Fred and Tempterrain are wrong, when they claim that the long term slowing down of the rotation would presently be the reason for leap seconds. The reasons are more in the original definition of second and in short term variability, which has gone in the opposite direction.
Although the rotation of the Earth is slowing in long term, that change is very slow. At the same time changes in the shape of Earth may cause more rapid effects. Every major Earth quake has an influence on the speed of rotation. Rebounding of the Earth crust after the last Ice age has a speeding effect, which is, however, smaller than the effect of losing angular momentum.
Here we have, again, a variable that has a slow long term trend, but whose variations are affected more by short term phenomena. Here the time needed to be sure that long term trend wins is really long as the movements of continental plates and ice ages belong to the short term phenomena, which may win temporarily.
Rather than relay second hand what is available from sources, I think it would be helpful for readers to see a fuller analysis available at Leap Seconds. As far as I can tell, the declining rate of the Earth’s rotation remains an important factor requiring the addition of leap seconds. It is not the only factor.
More relevant to the original issue, there seems to be little doubt that the rotation rate is slowing rather than increasing.
Ice mass growing, 2 years out of date unless anyone has anything more recent.
J Martin – I think the problem with the newspaper article you cite as a source of information on Antarctic ice is not so much that it is out of date, which it is, but that it is misleading. There are now many studies showing a net loss of ice mass from Antarctica, but this is the result of melting in West Antarctica, with East Antarctica contributing little or even partially offsetting the West Antarctic loss. One recent study is by Rignot et al but there are several others.
As I already wrote, I do agree that the rotation of Earth is slowing down in the long term, but it’s worth noticing that the graph on the page that you linked shows the oppocite trend. My impression is that even now you have not understood that.
Leap seconds are added when the difference shown on that graph is positive and slowing down of the rotation means that the difference grows. What we see, however, is that the difference has diminished to a value that’s only slightly positive.
Pekka – Although I find some of the descriptions confusing, my interpretation differs from yours. The website states the following: “Since the first leap second in 1972, all leap seconds have been positive and there were 23 leap seconds in the 34 years to January, 2006. This pattern reflects the general slowing trend of the Earth due to tidal braking.” The statement relates the positive leap seconds to the slowing trend, specifically for the interval since 1972.
Compare this statement with the Graph showing variations since 1972 (actually 1973). The graph shows a generally downward slope since 1973, with 2008 about 2.5 milliseconds lower on the graph than 1973. If that 2.5 millisecond reduction simply denoted an unadjusted shortening in the length of day, it would contradict the statement in the above paragraph that the leap seconds added since 1972 reflected a “slowing trend”.
I interpret the graph, tentatively, to show an adjusted trend rather than an unadjusted one – in essence, a form of detrending designed to show the variability in the slowing rate but not a reversal, except possibly in the early 2000’s, when some values appeared to be negative or close to zero. The descriptions along the x axis suggest an adjustment of some type, but are not explained. I assume (again tentatively, because of a lack of an explicit explanation on the page), that the adjustment takes into account the added leap seconds. I also assume that this is reflected in the fact that the UTC, although described as a function of atomic time, is adjusted by adding leap seconds, and therefore has become increasingly divergent from atomic time as the Earth continues to slow.
In none of the sources I visited have I found any indication that the rotation has been growing faster since 1972 . All indicate the opposite – that except for a brief interval, the slowing has continued. Unless some new evidence emerges to contradict this, I accept slowing as an accurate description of what has been happening, and the graph as an indicator of variability but not of an increase in rotation rate. I’ll be happy to revise my conclusions if there are better explanations for what the site says has been happening.
The text and the graph appear contradictory, because they are contradictory. The difference is true, not something created by manipulating the data. That’s proven also by the reduces rate in adding leap seconds. The text discusses the long term phenomenon, which is certainly true; the graph is dominated by the short term variation, which has gone in the opposite direction. In terms of physics the recuction in the angular momentum of the Earth due to tidal effects has been smaller than the reduction of the moment of inertia due to the redistribution of the Earth mass closer to the axis. The angular momentum is expected to go down without a lower limit, while the moment of inertia has some lower bound. Therefore the long term trend wins ultimately, but that can take very long.
You may also notice that the long term trend is given in the text as 1.4 ms/day per century or 0.44 ms/day over the period of 35 years shown in the graph. The real change has been about 2.5 ms/day in the opposite direction. The short term change has been roughly as large as the opposite long term trend over a period of 200 years. The full range of variability due to an ice age or due to plate tectonics is still much larger.
From the text you may find the sentence: (Also, it is important to note that the current difference in the length of day from 86,400 seconds is the accumulation over nearly two centuries, not just the previous year.) . By that they may mean that the trend difference was zero 200 years ago and that the starting point was about 3 ms/day of as the cumulative effect of those 200 years. Now we see that the short term effects have made an essentially equal opposite change in just 30 years. Perhaps the difference in 1972 was after all not the average trend value, but the trend value is presently lower. Further research and a few centuries of accurate measurements will tell the answer more precisely.
I thank both Pekka and Herman Pope for helping me begin to unravel the complexities involved in timing the Earth’s rotation rate. My current perpective, which is still evolving, is the following:
1. Because of the long term slowing of rotation, leap seconds must be added at intervals to atomic time in order to keep it from growing more and more divergent from mean solar time, which reflects the slowing..
2. That slowing has continued recently. Nevertheless, Herman Pope was completely correct in citing dramatic reductions in the frequency of leap second addition as evidence for a change from slowing to faster rotation. That particular interval was temporary – from about 1999 to 2005 – and slowing resumed in 2006, with leap second additions becoming more frequent again.
3. The graph that Pekka and I have been discussing on the Leap Second website is more complicated to interpret than might first seem. As I suspected, it appears to show detrended data, and so it doesn’t give us actual rotation rates (expressed as length of day, LOD) as they have changed over time. The detrending consists of the removal of the long term slowing trends. I have seen various estimates of these trends, including a figure of about 2.3 milliseconds/century for slowing due to tidal friction, partially offset by an acceleration of about 0.5 to 0.6 ms/century from isostatic rebound. This number, however, may vary considerably during different intervals and is affected by climate conditions, including global warming and ENSO.
4. I don’t know the value of the trend during 1972-2008. A rough hint can be found in the JGR paper on Length of Day by comparing the detrended data in Figure 1 with the Figure 9 data which appear to be detrended, and which show a flat 1980-2000 slope compared with the steep decline in Figure 1. Detrended data are also shown over longer intervals in the 2007 NASA study. Figure 1d shows the interval from 1972 when leap second additions were first instituted, whereas Figure 4d includes data starting in 1962. It is clear that both short term ups and downs in rotation rate have been observed, punctuating the long term slowing. LOD was at a peak (slowed rotation) in 1972, and the net change since then in the detrended data has been an LOD shortening, whereas the 1962 values were smaller and showed a rise in LOD to the 1972 peak. In both cases, it can be seen that the most recent changes in the figures involved slowing (rising LOD). If one estimates a reasonable value for the subtracted trend, it appears that non-trended results would show a slight net reduction in LOD with 1972 as a starting point, but a net increase in LOD from 1962.
The idea of dismissing weather patterns in order to force climate change through will surely be remembered as the most idiotic of the century. It’s all back to “and then a miracle happens” material.
The two graphs in this post show Hansen to be stating falsehoods:
One graph shows that Hansen’s GISS data match scenario “C” of the climate models representing a decrease in emissions to the 1990 level when actual emissions are about 10% greater than what Hansen predicted for his scenario “A”.
The other graph of HadCRUT3 data plotted against CO2 concentration shows a near perfect linear increase in CO2 concentration contrary to the accelerating increase predicted by Hansen because of his false concept that CO2 emissions from fossil fuels are the prime source of this increase, but more importantly the graph shows that since 2002 the globe has been cooling in spite of this linear increase in CO2.
At the cuirrent rate of increase of 2ppmv/year by 2100 the CO2 concentration will only be 566ppmv and this is well below the acceptable level that Hansen asked Congress to attain in his presentation on June 23, 1988.
Hansen’s rolling of the climate dice is craps without the “s”
The global hadcrut for GISS met station switcheroo strikes again.
Hansen’s 1988 “dice roll” was a disaster, whether one compares it with Hansen’s GIStemp or with IPCC’s preferred HadCRUT3.
Either way, Hansen’s warming forecast for BaU CO2 emissions (Case A) is exaggerated by 2+. This is quite simply because his model used a 2xCO2 climate sensitivity , which was also exaggerated by 2+
In fact CO2 emissions were actually a bit higher than those estimated by Hansen for Case A.
The actual temperature development, however, was about the same as Hansen’s Case C, a scenario assuming no further CO2 emissions after 2000.
Except for his “senior statesman” status in some climatology circles, Hansen has lost all credibility. It’s time for him to quietly go to the pasture, rather than to publish more alarmist nonsense.
“In fact CO2 emissions were actually a bit higher than those estimated by Hansen for Case A.”
Hansen’s emission scenarios were NOT just for CO2.
Emissions have been slightly below his scenario B.
“Either way, Hansen’s warming forecast for BaU CO2 emissions (Case A) is exaggerated by 2+.”
And of course the denier classic of misrepresenting the scenarios — got any new ones, guys? These are boring.
Hansen’s predictions were based on GISS met station data only, not any global land and ocean index.
Use this data set for proper comparisons.
Maybe you should reread the papers involved.
Where do you get the idea that the IPCC prefers HadCRUT3?
To clear up your confusion:
– Hansen’s 1988 forecast was off by 2X1 whether one compares it with HadCRUT3 or GIStemp.
– Hansen’s Scenario A assumed slightly less CO2 emissions growth rate than actually occurred. The other two Scenarios assumed much less human CO2.
– The actual temperature record was closest to Hansen Scenario C, which assumed no further CO2 emissions after 2000.
– IPCC refers to the HadCRUT3 record repeatedly in its statements on global warming (AR4 WG1 SPM). This record appears to be the reference record for IPCC claims.
Hope this helps.
First, Hansen’s predictions are completely separate from the IPCC.
Second, his model and predictions were based on Met station data. So his predictions should be compared to this database.
Which lies pretty flat on top of scenario B.
And the sensitivity used in his model might be a little higher because it was modeling the land only response, which would be expected to be a little higher.
You are pretty much wrong on everything here.
And just because HADCRUT3 is mentioned in the IPCC reports, how can you assume that it is the preferred database.
It states annual mean global (not land only) temperature change on his graph. Can you identify where you get it is land only? I don’t recall reading that and don’t have time to go over it again.
Take a look at the chart in Hansen’s 1988 paper on page 9347.
The note at the bottom of the chart says the data are from Hansen and Lebedeff [1987,1988]
“We analyze surface air temperature data from available meteorological stations with principal focus on the period 1880-1985.”
From Hansen and Lebedeff
lolwot, Emissions have grown exponentially, as in Scenario A. However, Hansen apparently got the percentage of emissions that would remain in the atmosphere very wrong. I’ve seen the Skeptical Science cherry picking rationalization on this and its bogus. Hansen must take blame for all the errors in his predictions.
Scenario A is based upon the trace gas emissions growth rate seen in the 1970s and 1980s.
How does this audited graph look to you?
Thanks bob, so your argument is they didn’t have the data base to make accurate projections as opposed to the projections themselves are only including the land.
Not at all Steven,
The argument I am making is that he used GISS met station database to make his predictions, and thus the judgement of how accurate those predictions were should be made using the same database.
Bob, they did project the oceans and I’m not sure that saying because they were working with a land dominated data base that should be an excuse to limit the results to land. They did make calculations regarding the oceans and adjusted the anticipated temperatures down because of these adjustments. To compare their land and ocean projections and say it fits land only is just another way of saying their projections were too high.
I think the divergence between Scenario C and Scenario B is so small in 2010 that there simply is no reasonable argument to be surprised observed temp, regardless of the series used for analysis, is below Scenario C at this time. The ENSO ups will be able to make up that small of a difference in a fairly short period of time.
That is why RC started including CRU and GISS Land and Ocean in their annual update, and why being below Scenario C at this time is a little concern to them.
So have fun with it while you can. By 2015 your fun will have turned into a sunburn.
Hansen remarks in his 1988 paper that “The transient response of the climate system on decadal time scales depends crucially on the response of the ocean, for which adequate understanding and dynamical models are not available”
I can’t hardly disagree with that since I would argue they still aren’t available.
–> …because that is a time of little global temperature trend just prior to the rapid global warming in recent decades.
Or, is that a time when weather stopped and when the global warming hoax and scare tactics began?
This paper by Hansen et al has not yet been submitted for publication, and if published, would undoubtedly be modified to correct errors and ensure that inadequately documented claims are expressed more tentatively, including the assertion about past Holocene temperature. I agree, though, that it is an informative contribution to our perceptions about climate change impacts. While, global temperature changes are typically expressed as mean values, changes in the frequency of extremes often exert greater impact, and the paper describes more dramatic changes toward the high temperature extremes than have generally been appreciated.. Land extremes will be more frequent than ocean extremes, and these are often obscured by global mean data. These extremes, as the paper describes, will also exert hydrologic impacts, with a tendency at least in some regions for drought-prone regions to become drier (e.g., at the Hadley cell edges) and regions of excessive precipitation to experience more frequent heavy rains and possible flooding. This is not captured by data on mean precipitation, and is an area the demands much further study for its potential impacts.
The future impact of further rises in global mean temperature on human and animal heat tolerance deserves attention, given the consequences observed from some recent heat waves. Neither extreme heat or cold deviations are salutary, but it is the former that appear likely to increasingly outnumber the latter as the climate warms. There are also absolute limits on heat tolerance, some of these described in the 2010 Sherwood and Huber paper on An Adaptability Limit to Heat Stress. In essence, the Second Law of Thermodynamics does not allow an object to lose heat to the environment when the wet bulb thermometer temperature (Tw) of the environment exceeds the temperature of the object. For humans, an intolerable Tw probably exceeds 35 C for extended intervals. This does not pertain currently to any large regions, but might occur regionally for severe future global temperature rises. Significant smaller rises (e.g., 4 C) would not make many regions literally uninhabitable but would bring some areas close enough to the tolerability limit for human activities and welfare to enjoy little in the way of safety margins.
Dr. Curry’s comment on the paper includes a statement that I believe contains some misinterpretations: ” The paper implicitly assumes that all of the warming since 1980 is AGW (whereas even the IPCC only says “most”, implying >50%).” The paper does not refer to “all” post-1980 warming but states that this warming is “primarily a human-made effect”. “Human-made” refers not only to increased ghg concentrations but a reduction in anthropogenic cooling aerosols, and the conclusion is well supported by the data. Similarly, the IPCC’s well known claim about “most” warming, while attributing it to ghgs, referred to warming since about 1950 rather than 1980. The evidence for this conclusion has been discussed extensively elsewhere, and I won’t repeat it here. However, the Hansen and IPCC statements are not in conflict.
Fred, Hansen’s overarching conclusion seems to imply substantially more than 50% of warming since 1980 is attributable to AGW
Could you quote the section where he says that?
Referring to my question, it pertains to ghgs. “Anthropogenic” includes both ghg increases and cooling aerosol reductions. In that sense, attributing most post-1980 warming to “human-made” influences is reasonable.
We conclude that extreme heat waves, such as that in Texas and Oklahoma in 2011 and Moscow in 2010, were “caused” by global warming, because their likelihood was negligible prior to the recent rapid global warming.
That doesn’t specify the cause of the warming.
It is implied by the first two paragraphs of the paper:
The greatest barrier to public recognition of human-made climate change is the natural variability of climate. How can a person discern long-term climate change, given the notorious variability of local weather and climate from day to day and year to year?
This question assumes great practical importance, because of the need for the public to appreciate the significance of human-made global warming. Actions to stem emissions of the gases that cause global warming are unlikely to approach what is needed until the public perceives that human-made climate change is underway and will have unacceptable consequences if effective actions are not taken to slow the climate change. Early recognition of climate change is critical. Stabilizing climate with conditions resembling those of the Holocene, the world in which civilization developed, can only be achieved if rapid reduction of fossil fuel emissions begins soon (1).
The statement doesn’t support the claim that Hansen is attributing all or even most post-1980 warming to ghgs. I find no evidence in the paper for that claim. He is almost certainly correct in the statement I quoted earlier that most post-1980 warming was “human made”.
It’s pretty obvious to me. If you condense the argument to bullet points, he’s saying:
• We need a new way to motivate the masses to get excited about anthropoegenic climate change,
• Therefore, we need to show that there’s something extraordinary about the past 30 years in order to support the claim about anthropoegenic climate change.
It doesn’t take a PhD candidate in philosophy to infer form that that either:
• Hansen is directly claiming that the extreme weather of the past 30 years is a consequence of anthropogenic climate change, or
• Hansen is being disingenuous and trying to pull a fast one by confusing the two.
Which would you rather believe?
Fred, the paragraph Judith offers does not say stabilization of the climate can be achieved by increasing aerosols and reducing ghg. it says:
“Stabilizing climate with conditions resembling those of the Holocene, the world in which civilization developed, can only be achieved if rapid reduction of fossil fuel emissions begins soon.”
The key words being ‘can only’. This statement in no way infers that anything other than man-made ghg is responsible for the warming. So how can you say ‘the statement does not support the claim that Hansen is attributing all or even most post-1980 warming to ghgs.’ ??
John – I don’t think that’s true. Hansen is correct in stating that stabilization requires reducing fossil fuel emissions. It does not, however, imply that he thinks only ghgs have been responsible for the warming. In fact, quite the opposite – he has been a strong proponent of the principle that anthropogenic cooling aerosols have been a strong influence on global mean temperature, and that reducing them would exert a strong warming influence.
I’m not sure this point deserves all the attention it has received in terms of column inches over the past few hours, but I don’t see any way to get around my original point – Hansen has not (in this paper) attributed most post-1980 warming to ghgs, but he has attributed most post-1980 warming to human activity. I think the evidence supports him on that.
“I’m not sure this point deserves all the attention it has received in terms of column inches over the past few hours”
I agree, lets leave it at that. :)
Hansen writes in such a way that those prone to blame it all on man can
feel supported by his analysis.
Those critical of him, have a hard time getting a foothold
Defenders, such as fred, can then say
” he didnt say that exactly”
This type of writing is par for the course. Its a studied precise ambiguity that allows him to have it both ways.
Perhaps Judith took lessons?
Fred Moolten | January 6, 2012 at 2:43 pm |
“Referring to my question, it pertains to ghgs. “Anthropogenic” includes both ghg increases and cooling aerosol reductions. In that sense, attributing most post-1980 warming to “human-made” influences is reasonable.”
So now it’s the magic ghg/aerosols stick. You just wish something and it becomes true. It’s the CO2 Fred, the Carbon as it’s called.
Mosher: “Those critical of him, have a hard time getting a foothold”
Yeah, those who have an a priori bias just can’t get ahold of the evidence on which to grind their axes, poor dears.
Fred Moolten and John Carpenter
Fred, you may be right that Hansen neither says specifically in just those words:
“GHGs have been the primary cause of post-1980 warming” nor
“Current temperatures are the warmest ever throughout the Holocene”
But you must admit that both our host and John Carpenter are correct in saying that he has inferred that both of these statements are correct with the statements that were cited.
One has to look at the message, which Hansen wanted to convey.
And this is very clear to most readers of his paper.
It is also clear to me that Hansen has put his foot in his mouth so many times in the past that he may well now have a team of lawyers and PR experts combing through his papers for any possible controversial wordmanship that needs reframing (but that part is only my unfounded suspicion.)
I’m surprised that this small point on Hansen’s attribution of warming for the post-1880 interval continues to trouble some readers. My suggestion is that if they want to know what Hansen meant when he stated that most post-1980 warming was “human-made”, they should email him. I’m not 100% sure myself, but I think it’s most likely that “human-made” was deliberately chosen because Hansen doesn’t want to claim most warming was due to ghgs, even though ghgs are a particular concern for him. This is reinforced by his emphasis in other work on the strong influence of cooling aerosols (or their absence) on temperature. Others who want to criticize him for what he didn’t say, and probably didn’t mean, will have their own views, but those might be clarified via an email to Hansen.
Were ghgs responsible for most post-1980 warming? I have seen neither claims nor specific data on that point from Hansen or others. Despite the importance of reduced aerosol cooling during that interval, it’s possible that the ghg influence may still have been dominant, but this conclusion is less strongly supported than the dominant role of ghgs when the post-1950 interval is the one in question.
Hansen’s interest in ‘cooling aerosols’ developed when he sought a bodge to explain his abysmal predictions. His confirmation bias is even more pathological than yours, Fred, and probably from more malicious motivation.
It has nothing to do with an apriori basis. It has to do with the particular style of writing. Please attend to what I say. You will find these type of arguments happening all the time on both sides of the fence.
He said X.
Show me exactly where he said X
Now the funny thing is that you think and michael think, that I am critical of this.
“Fred, Hansen’s overarching conclusion seems to imply substantially more than 50% of warming since 1980 is attributable to AGW”
Without reopening the discussion of what Hansen said/meant, I have a question specifically for you, Dr. Curry, if you don’t mind.
You have argued that it is premature to attribute most warming to AGW with high confidence, because of uncertainty related to natural variability.
Let’s take that as fact. Still, in order to do things like attribution analyses, we need to estimate the contribution of AGW to recent warming.
My question: isn’t the central estimate for that contribution still about 100%?
Proving greater uncertainty broadens the range of possible values, but unless I am really missing something (possible), it broadens them in both directions. Natural forcings could be positive or negative over the recent past; establishing greater uncertainty does not tell us which.
We still do not have a candidate for a “natural” warming influence, with solar forcing flat, and volcanic activity flat.
So isn’t the most reasonable way to proceed to continue to calculate the effects of AGW as similar to all of the recent warming, given that it could be more (net negative natural forcing) as well as less (net positive natural forcing)? Until we have a strong natural forcing or forcings in mind, we don’t know which.
Is this your thinking, or do you think there is a convincing case to be made that the uncertainty is mostly monopolar in the direction of positive natural forcings?
Edim – So now it’s the magic ghg/aerosols stick. You just wish something and it becomes true.
Kim – Hansen’s interest in ‘cooling aerosols’ developed when he sought a bodge to explain his abysmal predictions. His confirmation bias is even more pathological than yours, Fred, and probably from more malicious motivation. …
You will note his 1988 graphs, labeled:
CO2 + trace gases
CO2 + trace gases + aerosols
The above is a reference to volcanic aerosols, which cool.
In 1990 Hansen wrote:
“Although in certain circumstances, such as the absorbing haze in the Arctic, anthropogenic aerosols can have a warming effect, the overall direct radiative impact of man-made aerosols is clearly one of cooling.”
Just to place some numbers around my thought from above (http://judithcurry.com/2012/01/06/the-new-climate-dice/#comment-157346) let’s suppose we consider the current warming, if 100% human-cause, compatible with a climate sensitivity of 1.5C — 4.5C/doubling.
Now we suppose that there is a powerful natural variability that is responsible for 50% of the warming trend. We do not know what this might be; we have not been able to detect it, but since we don’t know everything about natural variability, we accept it as possible. Now the observed response of the climate system to human activity is compatible with a climate sensitivity of 0.75C — 2.25C/doubling.
But if principled uncertainty, rather than observed natural warming, is the reason for supposing this to be so, then it would seem the opposite proposition is just as reasonable — that absent human influence, a cooling of 50% of the observed warming trend might be unmasked. Such that the actual human forcing is 150% of what we observe, compatible with a climate sensitivity of 2.25C — 6.75C per doubling.
If indeed both are possible, then instead of being constrained in a band from 1.5C — 4.5C, the modern climate response would be compatible with a climate sensitivity of 0.75C — 6.75C.
Unless the uncertainty operates in only one direction, for some reason, it would seem that the assumption that current warming is 100% human-caused remains a reasonable working hypothesis, except insofar that if you are right about the greater uncertainty, it implies a much larger “fat tail” of climate sensitivity.
anthro CO2 warming > 0
heat wave attribution to global warming, regardless of source > 0
heat wave deaths > 0
then it follows that
AGW deaths > 0.
Unfortunately it is a cost benefit analysis. Value of a statistical life??
anthro CO2 warming > 0
cold wave attribution to global warming, regardless of source 0
then it follows that
AGW deaths hot weather deaths (as many studies have shown)
then it follows that
NET AGW deaths < 0 (i.e. fewer people die if we have AGW than if we do not)
Right? (Just an exercise in logic.)
Correction [system does not like “less than” sign]
Please ignore first post
anthro CO2 warming is greater than 0
cold wave attribution to global warming, regardless of source is less than 0 (fewer cold days and nights with AGW)
then it follows that
AGW deaths (from cold weather) are less than 0 (fewer people die from cold weather if we have AGW)
AND, more importantly:
anthro warming is greater than 0
heat wave attribution to global warming, regardless of source is greater than 0
cold wave attribution to global warming, regardless of source is less than 0 (fewer cold days and nights with AGW)
hot weather deaths are less than cold weather deaths (as many studies have shown)
then it follows that
NET AGW deaths (from heat AND cold) are less than 0 (i.e. fewer people die if we have AGW than if we do not)
Right? (Just an exercise in logic.)
that’s interesting, because even though i am skeptical of C-AGW claims, i still tend to automatically think of it as a negative, and exclude the potential benefits.
1783 was deemed the ‘‘Annus Mirabilis’’ where the coincidence of several large-scale natural disasters and the extraordinary state of the atmosphere that caused great public concern.Thorsarsen and Self 2003.
A very strong earthquake struck in Calabria, Italy, on 5 February, marking the onset of earthquake activity that lasted well into the
summer [Hamilton, 1783]. In late February 1783, a submarine
eruption off the southwest coast of Iceland formed a new island, ‘‘Ny´ey’’ (New Island) that disappeared shortly afterward [Stephensen, 1783; Thorarinsson, 1965]. In addition, Asama volcano in Japan erupted intermittently from May to August 1783 [Aramaki, 1956] and a small eruption occurred at Vesuvius in August.
The concomitant El Nino Grove 2007 added to the effects producing global consequences.eg
By coincidence the 1780s and 1790s, which is the period explored in
this article, was a period of extraordinary climatic anomaly, characterised
above all by an El Niño event or series of continuous El Niño events, observable from as early as 1788 to as late as 1796. We are beginning to realise now, by a combination of high resolution archival detail and a
limited amount of physical proxy data, that this extreme event with its
dramatic climatic and historic consequences, which we shall call the Great El Niño, was arguably the strongest and most prolonged El Niño event of the millennium A.D. 1000–2000
The coinicidence of a number of random events over a short period is neither unusual ie an inconvenient historical fact,or ameneable to a random collection of primitive mathematical ( where solutions are open and infinite) models and appealing to closure relations is a well known no no.
There is a nice link on the historical moments .
The second troublesome property is that nature in its infinite ways tends to punish men who play dice eg Bernoulli,Feller 1951.
A good example for Gamblers is the paper that never was.
DRAFT March 29, 2006
Spotlight on Global Temperature
by James Hansen, Makiko Sato, Reto Ruedy, Ken Lo, David Lea and Martin Medina-Elizalde
Early model predictions of global warming proved accurate,the Pacific Ocean seems charged for a potential super-El Nino, and global temperature is poised to reach record, perhaps dangerous, levels.
SUPER EL NINO IN 2006-2007? We suggest that an El Nino is likely to originate in 2006 and that there is a good chance it will be a “super El Nino”, rivaling the 1983 and 1997-1998 El Ninos, which were successively labeled the “El Nino of the century” as they were of unprecedented strength in the previous 100 years (Fig. 1 of Fedorov and Philander 2000). Further, we argue that global warming causes an increase of such “super El Ninos”. Our rationale is based on interpretation of dominant mechanisms in the ENSO (El Nino Southern Oscillation) phenomenon, examination of historical SST data, and observed Pacific Ocean SST anomalies in February 2006.
One should follow Tolstoys warning when catastrophists start seeing ‘signs”
New justifications have now appeared in place of the antiquated,
obsolete, religious ones. These new justifications are just as
inadequate as the old ones, but as they are new their futility
cannot immediately be recognized by the majority of men. Besides
this, those who enjoy power propagate these new sophistries and
support them so skilfully that they seem irrefutable even to many
of those who suffer from the oppression these theories seek to
justify. These new justifications are termed ‘scientific’. But
by the term ‘scientific’ is understood just what was formerly
understood by the term ‘religious’: just as formerly everything
called ‘religious’ was held to be unquestionable simply because
it was called religious, so now all that is called ‘scientific’
is held to be unquestionable. In the present case the obsolete
religious justification of violence which consisted in the
recognition of the supernatural personality of the God-ordained
ruler (‘there is no power but of God’) has been superseded by the
‘scientific’ justification which puts forward, first, the assertion that because the coercion of man by man has existed in all ages, it follows that such coercion must continue to exist.
Fred, how come in your crystal ball doesn’t say that: the rainfall in sub-Sahara will increase? No need 3 guesses, only one. Because that wouldn’t scare anybody. Fear mongering is lucrative business. If CO2 distribution is evenly distributed and is got any affect; should be more rain / or less rain. Is your crystal ball made in East Anglia university – look at the label, please
JC. I agree that you have pointed to a significant defect in in this paper. The 30 base period (1951-1980) lives entirely within the cool phase of the PDO, while the following 30 year period is mostly warm phase. Yet, I find no mention of PDO, AMO or ENSO in the linked article.
Nowhere in the paper does it establish the irrelevance of ocean cycles. Has this become so obvious it does not deserve mention? If so, I’m sorry; I must have been sleeping too long again.
I think climate science consistently fools itself by being so myopic and concentrating on “anomalies” of the last 100 or 200 years or even comparing a base period of 20 or 30 years to another similar length base period. What about the last decade? Does it present anything to be alarmed about? Yes, we seem to have edged up to the top of a the latest warm cycle with temperature levels that have occurred many, many times before. Look at the very stable global temperature oscillations of the last 10,000 years, as evidenced in ice core data, and define “anomaly” for me…..any yearly average deviation from the 10,000 year average, or any more than a 2-sigma deviation, 3-sigma deviation? I would define anything that deviates more than +/- 2 deg C from the 10,000 year average to be an anomaly in the normal use of that term, because it never seems to get out of that range. (Humanity deals with typical 30-40 deg C temperature changes during each year due to seasonal effects, so calling a 2 deg C yearly temperature average devitation from a 10,000 year average an anomaly is even questionable and perhaps imperceptible ti the general public).
The yearly global average temperature oscillations from ice core records stay mostly within +/- 1 deg C of the 10,000 year average range and we are in that range today. I postulate that ice core data provide a better global average temperature record than does the often manipulated GISS surface temperature data base. I also postulate that defining a reliable “global average temperature” from that database is an ill-posed problem that will continue to generate controversy.
As a child, growing up in an un-airconditioned home during the years 1941-1959 on a large Southwest Louisiana rice and cattle plantation, the summers seemed to be a lot hotter and dreaded than do the summers now in my similar climate Houston TX area suburb air-conditioned home. Are the hotter summers Hansen et. al. are alarming us about really a problem that we need to urgently solve with megabucks and economic hardships? Rice crop yields are consistently much better now than back in the 1950’s and they are achieved in air-conditioned tractors and combines with much less human labor and heat stroke related problems. What are climate scientists so alarmed about? What do the common sense farmers think? They are out in these elements every day working with nature.
I hear and see on the news much more concern, loss of life and worker productivity issues regarding northern states cold and long winters and blizzards than I do the hot summer temperatures here on the Texas-Louisiana Gulf Coast. I consistently hear from the large number of folks moving to Texas from northern states that they would always prefer our hot summer months compared to their previous northern state winter months. Somehow it is easier for humans to adapt to the warmer temps than the colder temps. I’m more concerned about the next “little ice age”…and what will cause it.
The long term forecasters who’ve earned my respect by out forecasting the climate modelers season after season,year after year…including the UK MET with their endless warm, snowless winters and barbecue summers, and the ever ridiculous Jim Hansen with his perennial (and ever hopeful) prediction of super el nino’s that never come to pass, are in agreement that we’re on the cusp of a 20-30 year cooling…all based on natural climate drivers.. including a quiet sun. Loaded dice indeed.
One thing you have to admire about Hansen is he puts his money where his mouth is. He is not shy of making predictions and making predictions is what a good scientist does to see if he is right or not. Hansen has made predictions in the past where some have not come to pass and some are close. He’s making another prediction in this paper. If he is right, we should expect, over the next six years, 4 warmer than average winters. We can now see if it comes to pass.
Puts his money where his mouth is? I think it works the other way around, if you look a little.
Personally, I would never put my mouth where my money is.
I think the US midwest is undergoing another 3-sigma event.
I heard that the Americans for truth, justice and the American way are refurbishing Alkatraz for Hanson, Briffa and Al Gore… just a gossip…
Texas had a drought didn’t it?
Can’t find a reconstruction of drought for Texas, New Mexico is pretty close. I am sure that AGW had to be the cause of the Texas heat wave, since it is unprecedented and all.
This has south central Texas since 1650
That link takes me to the state of climate drought page with the monthly look up. Does it have any way to make a historical chart that I missed seeing?
Scroll down near the bottom of the page.
Just to take one example Hansen cites –
“The deadly Russian heat wave of 2010 was due to a natural atmospheric phenomenon often associated with weather extremes, according to a new NOAA study.”
“western Russia has not experienced significant climate warming during the summer season over the 130 years from 1880-2009, despite significant warming of globally averaged temperatures during that time.”
The same sort of heatwave strikes any area with a blocking high (eg: the UK and W. Europe in 1976, which no-one blamed on global warming because Newsweek had Ice Ages on the cover).
I think the jury on this paper should retire to render it’s verdict. Meanwhile, Hansen should just retire.
This comment and others like it are good examples of why it helps to use a dice analogy. Yes, we know that the climate has rolled ‘6’s before; more ‘6’s are being rolled now, about 10 times more. That is the point you all seem to be missing.
Since the Moscow heatwave wad similar to earlier Russian heatwaves, the next question is why does Hansen & gang claim they know the chances of the 2010 event were supposed to be? It is always easier to make predictions after the event. This paper seems at first glance to be very easy.
Willis is surprised that anyone pays attention to James Hansen. I wouldn’t be surprised if bail bondsmen paid attention to Hansen since he seems to frequently get involved in acts of civil disobedience. However, I’m astounded that anyone seriously interested in real science listens to his hyper-alarmist predictions for the future and misrepresentations of the past. While most climate scientists are smart enough to place their versions of Armageddon far enough in the future, ensuring that they will be at least retired, if not dead when these catastrophes happen or don’t happen, Hansen has not been so prudent. In June of 1986, Hansen predicted that on top of any temperature increases occurring in the remainder of the 20th century, the first decade of the 21st century would see a further increase of 2 to 4 degrees. As I’m sure you all know that decade (2001-2011) saw no increase in temperature whatsoever!
Jeff – Hansen is an interesting anomaly. He is brilliant, insightful, a major contributor to our climate understanding, opinionated, partisan, and sometimes very wrong. The problem is this – if you already have a strong background in geophysics and climatology, you can learn a great deal from his recent papers, but if your background is weak or superficial, you will have trouble determining what is worth remembering and what is misleading.
This new paper is no exception.
Fred Moolten said, “He is brilliant, insightful, a major contributor to our climate understanding, opinionated, partisan, and sometimes very wrong.”
Believe it or not, I think all those traits apply to many climate scientists and scientists in general, it is not a bad thing. No one can avoid being wrong sometimes. The measure is how you deal with it. The problem is the brilliant, opinionated, partisan and sometimes right scientists that bite their lips, when they can be major contributors to climate science..
Why is he a major contributor to our climate understanding? What exactly is his claim to fame? Modelling Venus? Penning endless polemics on Columbia stationary? Collating data? Writing popeyed books? I’m not seeing it.
Fred just told you that “if you already have a strong background in geophysics and climatology” (in other words, you are properly indoctrinated) then you will see how smart Hansen is. However, “if your background is weak or superficial” ( if you are a stupid denier) then you won’t get it. The science is settled, and Hansen settled it. Fred should have taken his act to Durban. He could have made a difference.
Fred, so what? For all his brilliance Hansen has been rent seekimg, fear mongering, wrong.
Hunter – the title of the NOAA paper was “Was There a Basis for Anticipating the 2010 Russian Heat Wave?”. The answer, of course, was NO.
cui bono, which begs the question of how Hansen gets this paper published outside of the op-ed section.
Let the man’s actions speak louder than his words. He has participated in civil disobedience and disruptive behaviour. He encourages others to similar acts, even to acts of vandalism, all in the name of the church of catastrophic AGW. Let’s not give the man’s words undue influence.
Or more to the point, if you’re going to openly throw in with one political side concerning that you’re purporting to be a technical expert about, it’s going to take a toll on your professional credibility. At the very least, there’s a conflict of interest in play. Especially in Hansen’s case, with all the political prize money that we all know about. If he wanted to stay clean, he could have refused the money.
The issue I have with hansen is different
I believe in AGW, unfortunately hansen has come to represent the science itself.
He cannot afford to make mistakes. He is not an individual.
He is the science.
Hertz had OJ
We got hansen
That sucks from my perspective
Very well said:
Hansen is villain.
But what can you expect
from sons of disloyal subjects
of the Crown?
Looks like clowns. Huh?
It is good to see that being disobedient is finally getting the harsh treatment that it deserves. Why should the power suffer for others’ suffrage. The liberals have all gone away eh?
Don’t overlook his Promo of that book on why AGW believers should do global terror and destruction.
Fred – Hansen may once have been brilliant, insightful, and just “sometimes very wrong” (as my reference pointed out), but the judgement (or lack thereof) and common sense (or lack thereof) demonstrated by the man today is very significant in determining how seriously we should take his opinions. (And in climate science today, where almost nothing has been proven or disproven, the positions of AGW supporters or sceptics, no matter how learned in either case, are just opinions.) Do you think it demonstrates good judgement or common sense for the head of GISS (a government funded agency that is supposed to keep unbiased temperature records, and do unbiased study of climate change) to be more biased (or “partisan” as you politely put it) than any AGW supporter this side of Joe Romm, to engage in a variety of acts of civil disobedience, to make outrageous statements (such as declaring that the executives of all the major oil companies should be put in prison), and generally behaving in a totally unprofessional manner?
Jeff – I would have to think about it further to decide where I approve or disapprove of Hansen’s judgment. My point was different – that it’s possible to learn from him on climate topics as long as you have some way of distinguishing valid insights from unsupportable claims. Where I disagree with you is the idea that every conclusion in current climate change literature is simply an “opinion”, but that’s too broad a subject to tackle here.
Fred Moolton: – that it’s possible to learn from him on climate topics as long as you have some way of distinguishing valid insights from unsupportable claims.
My experience (anecdote alert!) has been that you best concentrate on his peer-reviewed papers.
Fred N. “Let’s not give the man’s words undue influence.”
Common parlance: don’t play with anyone who provides loaded dice. No money. No time of day. Julius Caesar when crossing the Rubicon: “The die is cast.” And so it is with climate change. We go forth and live with the consequences, adapting all along as we as a species have done before. Even creatures that foul their nests, seem to live to see another day, and we will too. There is no undoing what we have done in the past; remediation yes, but not likely to return to the pristine state, unadulterated. A focus on CO2 has distracted from actionable remediation: fuels with less air, water & ground pollution. Recycling of base materials. Economic actions mindful of the entirety of their impacts. All Yes. Launching irrelevant tirades at the wind? No, I’m not playing.
Last year Hansen was all wound up about Death Trains – a variation of linking skeptics to Holocaust Deniers and now he’s trying to torque the story with a drive by hint at “Rolling the Dice” i.e taking a gamble.
A truly desperate man, watching his life’s work collapse in a cesspit of predictions and projections that haven’t happened.
He’d be much happier if lower Manhattan was flooding like he predicted. Instead he dreams up new variations of the old “Sky is Falling” hysteria in another attempt to gain the spotlight he loves, craves and needs.
Last year Hansen was all wound up about Death Trains – a variation of linking skeptics to Holocaust Deniers
The ability of skeptics to take spurious offence knows no bounds.
The ability of Believers to not believe what Hansen actually said and did knows no bounds.
Hansen has devolved from a credible scientist 30 years ago into a politically motivated old fool who will do and say anything in desperate attempts to restore a very tattered reputation.
When the history is written of the Great Global Warming Hysteria and Fear Mongering episode, Hansen, the IPCC, the Team, the whole lot etc . . . will all be poster kiddies for how science can so easily be subverted by personal ambition, vanity and a narrow minded, cherry picking approach to science.
Fred – In Hansen’s case, distinguishing valid insights from unsupportable claims is akin to looking for a needle in a haystack given the number of preposterous predictions and statements that Hansen has made. (Your calling his claims merely “unsupportable” is a gross understatement.)
As for your disagreeing that conclusions in the climate science literature are just opinions, I suspect that this is a reflection of our different experiences. My background is mathematics. In mathematics, if the information you are starting with is not recognized as being identical for everyone concerned, your proof (or supposed proof) won’t even be considered. If you don’t present your proof to the “world” for others to go through with a fine tooth comb to look for possible errors in logic, your proof will be considered to not exist, and your “conclusion” will be simply a theory or an opinion. In climate science, since the data is often disputed (before and after being adjusted) and sometimes not even made public (“Why should I make the data available to you, when your aim is to try and find something wrong with it?” – Phil Jones), and since the computer code is often only partially given or not given at all, there is no proof to even attempt to confirm, let alone a proof that everyone accepts as being valid. Thus, conclusions in climate science by serious science standards are only opinions. QED
There are some Nobel Prize Winners in Physics who would disagree with you, but I have a sense that arguing about this isn’t going to lead to any resolution, so I’ll pass.
Fred – You’re right – there’s no point in arguing about it. I didn’t expect you to agree with me. As I implied, since (I assume) your background is not in mathematics (please correct me if I’m mistaken about that), I expect you to view things differently.
Fred’s also much smarter than you are. Just ask him.
On the whole, this was a better paper: http://www.nature.com/nature/journal/v470/n7334/full/nature09763.html,
because it modeled the extreme values rather than the standard deviations.
Other than that, and that attribution to CO2 change can’t be supported, the feature paper looks ok.
The extreme value distribution is an incredibly beautiful thing, but the misapplication in that paper [ http://www.atmosp.physics.utoronto.ca/~jclub/journalclub_files/MinPrecipExt.pdf ] leverages a severe abuse of Central Limit Theorem. Such intensely severe abstract corruption is beyond any hope of rehabilitation. So reviling are the untenable assumptions of this particular paper that I think for the first time I’m understanding why some resort to fighting climate science via political tactics.
Is this something we should do a thread on: application of extreme value theory to weather/climate events? I would be most interested in a guest post on this.
Good idea. tamino has done one. He is a good teacher. Reach out. Ask him to expand on his Nov 6, 2010 post.
For now I can add 3 points:
1. Why curve it? Why not use the empirical percentiles? (See Cleveland’s book on Data Visualization, which has an excellent chapter on exactly this issue.)
2. Do these authors really think the hydrologic cycle is a function of curved percentiles?? i.e. as opposed to physical absolutes?? One would certainly hope not! (For the interested reader, I can recommend the works of N.S. Sidorenkov.)
3. Review the concept “regression to the mean” from an intro-stats textbook. Not only are they playing games 1 & 2, they’ve gone the extra length of playing CLT yet further with 5 year averages.
As I say: There will be no way to rehabilitate. These folks are write-offs in my book. Victims of DEEP (i.e. culturally engrained) abstract miscomplexification, wholly divorced from sensible applied (in the engineering sense) notions of appropriate diagnostics. Shameful & even sinful that funding is going to them. Society & civilization will fall if these are the pillars upon which we are to build. The culture of applying haphazard assumptions as occurs notably in the fields of economics, physics, & mathematical statistics is potentially a grave threat to our society & civilization. Our best hope may be that the next generation is expeditious in maturing & preparing to assertively seize the reigns and halt the old-school error cascade.
If someone runs a guest post on EVD, I can contribute with comments, but I’m orders of magnitude short on the time needed to write a formal article. Best Regards.
Paul Vaughan: http://www.atmosp.physics.utoronto.ca/~jclub/journalclub_files/MinPrecipExt.pdf ] leverages a severe abuse of Central Limit Theorem.
I disagree with you there. The CLT applies to the distribution of the mean of an increasingly large sequence of RVs, subject only to modest restrictions on the means and variances (e.g., that the variances be finite, and that each rv have a diminishing effect on the sum of the variances), and that the RVs not be too dependent. N might not be sufficiently large for the theorem to be sufficiently accurate, but there is no other reason to think that it was abused in this case. But what is “intensely severe abstract corruption”? You are not criticising the paper because of its abstract, are you?
Obviously it was not the last word, but I hope that it is copied by other researchers on that and other data sets.
Paul Vaughan: 1. Why curve it? Why not use the empirical percentiles? (See Cleveland’s book on Data Visualization, which has an excellent chapter on exactly this issue.)
Possibly you mean quantile regression. I think that’s a good alternative, and should be pursued. You still need some way to summarize and test whether, over all region, there is evidence for any king of net trend. For that you’d probably use the CLT on the mean across regions of some parameter estimated on each region. You probably can’t, in this setting, make a global test without making some assumption that can’t formally be justified by a rigorous derivation. You’d pick something, using heuristic reasoning, that you judge to be sufficiently accurate.
The reason for estimating the curves is that, if they fit well enough, the percentiles estimated from the fitted curves have lower sampling variability than the percentiles estimated from the empirical CDF.
I agree that plenty more could be said, but maybe we’re wise to stop before consuming too much time. Cheers.
By the way, thanks for the link MattStat. That paper was quite interesting from an abstract perspective. Survival analysis is seductively attractive.
Why I’m clearing it from my plate today:
Have a look at Figure 6 on p.12 here for a generalized overview:
Lilly, J.M.: & Olhede, S.C. (2009). Higher-order properties of analytic wavelets. IEEE Transactions on Signal Processing 57(1), 146-160.
Any ideas on how to express the Airy Wavelet in a different form? Any math specialists reading here? If so, do you have any ideas?
MattStat | January 7, 2012 at 4:40 pm | wrote:
“I disagree with you there. The CLT applies to the distribution of the mean of an increasingly large sequence of RVs, subject only to modest restrictions on the means and variances (e.g., that the variances be finite, and that each rv have a diminishing effect on the sum of the variances), and that the RVs not be too dependent. N might not be sufficiently large for the theorem to be sufficiently accurate, but there is no other reason to think that it was abused in this case.”
We can’t turn a blind eye to context. MattStat, we’ve got to be a LOT more careful with assumptions when we are outside of the abstract realm. Even though I’m extremely busy, I’ve decided that this is important enough to challenge you to state explicitly your assumptions (in real world context). I can see at least 4 serious problems (in context – not talking in the abstract here). I’m very curious to see if you see them.
I do appreciate that you’ve got me thinking quite carefully about how these cross-disciplinary “misunderstandings” (to use a polite term) arise.
Paul Vaughan: I’ve decided that this is important enough to challenge you to state explicitly your assumptions (in real world context).
To start with, let me repeat that my main point was a ranking: the Nature paper that I cited was better than the Hansen paper that is the feature paper, though it addressed rainfall rather than temperature. That didn’t mean it was beyond criticism.
If the Nature paper is made the feature paper by someone, perhaps we can address the details. Mathematical assumptions are never perfectly accurate as descriptions of the real world, so the question is not whether they are “true”, the question is whether they are “sufficiently accurate”. The Nature paper reported that the rainfall extremes had increased 7% over 50 years; if someone analyses the same problem with the same or related data, using the same or different methods, then we might discuss how different methods produce different results, or concordant results.
The two most important tests of assumptions now would be the panels of graphs justifying the generalized extreme value distributions, and justifying the distribution of the effect estimates. If the former are ok, and the latter is ok, then the conclusion is ok. Pending replications, one would not “believe” the conclusion.
Min, S.-K.; Zhang, X.; Zwiers, F.W.; & Hegerl, G.C. (2011). Human contribution to more-intense precipitation extremes. Nature 470, 378-381. doi:10.1038/nature09763.
It’s salient to the topic of this thread and it’s not even remotely a “sensible” application of “heuristics”. On the basis of absolute logic it’s egregiously & deeply fundamentally far from sensible contextually.
And it’s not just that the authors assume (a) unnatural warming that (b) can be extrapolated; that’s just what lures scrutinizing attention upon the most superficial, barely-educated glance.
I’ve made time to carry on from where I informally drafted a list of 3 serious concerns above…
“In fitting the GEV distribution, we assume that its location (µ), scale (σ), and shape (ξ) parameters are constant in time.”
This assumption is beyond absurd.
Their consideration of natural variability in supplementary section 5 is effortless — i.e. they didn’t even lift a finger.
Fitting diagnostics: Where are the Q-Q plots so we can assess the fits in the most straightforward & simple way possible? And MORE IMPORTANTLY: Where are the spatiotemporal Q-Q coplots??
In supplementary section 6 they exhibit extreme (how fitting) incompetence:
“El Niño and Southern Oscillation (ENSO) significantly influences extreme precipitation16,17 at local and regional scales in some parts of the world. However, the influence of ENSO on extreme precipitation is positive in some areas and negative in other areas, or the reverse, depending upon the phase of the ENSO cycle. That is, El-Nino events followed by La-Nina have opposing effects on extremes at a given location. As a result, the net influence of ENSO on continental scale means of precipitation extremes on times scales of a full ENSO cycle or longer is anticipated to be rather small. Our analysis as described below confirms this, and indicates that ENSO has not influenced on our detection and attribution results.”
They’re definitely victims of paradox. In whatever analyses they’ve done (or studied from others) to arrive at such a distorted view of nature, they’ve falsely (possibly unconsciously) assumed spatiotemporal stationarity, tangling themselves DEEP in paradoxical interpretation of stats (a guaranteed possibility when assumptions are violated by unrecognized systematic constraints). Painfully naive.
It keeps getting worse:
“We have tested the sensitivity of our detection results by using ENSO-residual observations. In order to keep all calculations within the scope of extreme value theory, we have removed the ENSO influence from the observed PI time series by employing the observed Southern Oscillation Index (SOI) as a covariate in our GEV model16.”
Elementary level terrestrial climate data exploration (accessible to low level amateurs) easily & expediently confirms with absolute certainty that the assumption of spatiotemporal stationarity is dead on arrival.
In keeping with the theme of extreme: Seeing professionals of supposed integrity “going with” such 1 + 1 = 1 (or is it 1 + 1 = 3?) assumptive ‘logic’ has an extreme impact on trust.
The supplementary notes are a blizzard of fundamentally misguided & patently untenable assumptions.
The abstraction’s an insult to nature, to society, & to civilization. It’s only out of a sense of responsibility that I make the time to write these comments during a very busy week
“[…] consistent with our expectation that the ENSO cycle influences at any one place would tend to average out during a given five-year period.”
They’ve certainly not studied ENSO periodicity carefully if this is what they think. They show no awareness of the effect of integration across spatiotemporal harmonics. They assume spatiotemporal stationarity, showing no awareness of multivariate phase reversals in interannual inter-regional climate variability.
The naivety of this particular paper reaches deeply insulting levels. Although bad assumptions are widespread in climate science, I can’t remember running into such egregiously abusive layered application.
Note what Dr. Curry had to say about the paper:
“I find this kind of analysis totally unconvincing, and it does not recognize the role of natural internal variability such as the Arctic Oscillation, La Nina, etc […]”
In the earlier thread on attribution Dr. Curry wisely referred to “[…] the statistical envelope of extreme events as influenced by the main climate regimes and teleconnection indices (e.g. AMO, PDO, ENSO) on a regional basis.”
Abstract extreme value theory (abstract not as in journal abstract, but rather as in abstract conception & abstract mathematics) is beautiful & seductive. It might be useful for modeling leftovers after we have a MUCH better handle on the spatiotemporal nonstationarity of natural variability.
The only sensible option is to resist the seductive temptation to apply abstract models so fundamentally corrupted at the contextual interface that they demand layered statistical paradox generating assumptions. Perhaps the authors will need to see multivariate examples of statistical paradoxes that arise under false assumptions of spatiotemporal stationarity to recognize & appreciate this, but hopefully such spoon-feeding will be unnecessary.
Many online climate discussion commenters might be quick to suspect professional deception by the authors. Note that I do not suggest deception. I see gross naivety (particularly a spectacular, inexcusable absence of spatiotemporal nonstationarity awareness).
It’s no safer following naive ‘leaders’ than it is following deceptive ones. The preceding comments have been volunteered in defense of society, civilization, & nature.
I strongly suggest that the authors begin patiently & carefully familiarizing themselves with nuances of global scale climate constraints indexed by Earth Orientation Parameters (EOP).
It’s always good to see that someone is left who can rise above the fear-mongering and doomsaying (right Anteros?).
I’m holding out hope that there are enough engineers to save us all (but I’ve started building my bunker just to be on the safe side).
No cause for alarm Joshua, just balance.
I hope you hired a good engineer to do the loads analysis on your bunker or the big bad wolf may blow it down
curryja: Is this something we should do a thread on: application of extreme value theory to weather/climate events? I would be most interested in a guest post on this.
When the Nature paper came out, was it discussed here at Climate Etc? Willis Eschenbach at WUWT and someone at RealClimate presented it, Willis critiqued and RC praised.
It is all a bit of nonsense. Central England is not large as even fraction of Texas but it has far more accurate and longer temperature records:
In the 350 year long data history the hottest summer was in 1976 (in the middle of the global cooling), while 2011 summer was 1C below average (15.3 C) and 3C below 1976, despite 2011 being the second warmest in the 350 year long record.
Just as a curiosity to mention that the 2011 CET summer was 2 degrees cooler than the summer of 1666 and for the same year (middle of the Mander minimum and the depth of the LIA) the winter was more than a degree warmer than in 2010 at the pinnacle of the modern global warming.
Hansen is talking nonsense.
This does not appear tp be a serious paper showing new findings on our planet’s climate.
The basic weakness of its logic is presented in this statement, right at the beginning:
The authors suggest that it will be possible to discern the effects of human-induced global warming “in the early 21st century”.
Well, hey, we are there and, despite all the discussions of “loaded dice” and statistical rationalizations to the contrary as presented in this paper, our climate is continuing on a “business-as-usual” pattern, having decided to stop warming around 11 years ago.
The claim that we are now warmer than any time in the Holocene sounds scary, but is unsubstantiated.
Some people may take this paper seriously.
I see it as nothing more than a “last gasp” attempt to try to keep the fear mongering on AGW alive despite the revelations of Climategate, etc., the doubts on the IPCC science that are being raised, the dismal failures at Copenhagen, Cancun and Durban, the US congressional rejection of cap and trade and the past 11 years of slight cooling trend.
Although he may still enjoy sort of a “senior statesman” immunity to many in the climate field, James E. Hansen has lost his credibility and relevance as a result of his constant doomsday predictions (which never happen in real life).
This paper will not help him get these back in my opinion.
Rising at a rate? At 3 mm/yr, when exactly is the West Side Highway in Manhattan going to be under water?
“’Climate dice,’ describing the chance of unusually warm or cool seasons relative to climatology, have become progressively ‘loaded’ in the past 30 years….”
Methinks I spy a freudian slip.
“Loaded dice,” as any gambler will tell you, are dice that have been manipulated to change the results of throwing said dice from random, to a result that matches the number the “loader” intends to bet on more frequently than chance would allow. In other words, cheating.
There are more than a few who would argue that climate models could be described as loaded dice, not to mention proxy reconstructions, Antarctic land temperature exrtrapolations, etc.
I understand this is not how Hansen intended the term to be used, but his choice of such a term suggesting human interference in determining the statistical outcome of what should be a normal physical process is…entertaining to say the least.
Psychologists would refer to Hansen’s reference to “loaded dice” as a “Freudian slip”.
It is difficult dealing with a paper that clearly has a political intent (like much of Hansen & Sato’s recent work this is very much a call to arms) as well as a scientific one (it has significant descriptive content).
Most of the first section through to Results and the end Discussion section fall into the category of the political. This includes a number of controversial assertions, often self-referenced, that have a weak relationship to the descriptive content. Some of these have been already picked up and debated by a number of commenters above (including JC in her post).
I’m not clear where the paper has been submitted, but assume it will be to a journal where appropriate peer review can be applied to this political content.
For my part I am more interested in the descriptive content. In the following comments I’d note I have looked at the Supplementary Information referred to (and I’m not even sure if it available on line).
First, picking up a point raised by P.E. @ January 6, 2012 at 1:14 pm this not an exercise in hypothesis testing. All the objections that have been made about attribution, why this period, the time frame of analysis, etc relate to hypothesis testing and therefore talk to this issue.
This is, as I have noted, simply a descriptive study. For that reason the authors political statements that suggest the study “proves” something (rather than being “suggestive”) have to be regarded as polemic.
If we turn to the study itself I think it is worth expanding on Willis Eschenbach @ January 6, 2012 at 1:28 pm. If we have a series of numbers steadily increasing over time and we compare the standard deviation towards the end of that period with the standard deviation at the beginning, the very surprising result would be if the first hadn’t shift up relative to the to second. (In fact I’m not sure you can get this result and maintain the assumption of normally distributed errors).
If you take this result out away from the domain of climate science and simplified it by removing the geographical elements this would make a good first year statistics course example to help understand some of the principles of standardising statistics, normal distributions, comparing out of population data with in-population, and how populations that have underlying processes in them can distort results.
However I strongly suspect that any such exercise would have gone on to look at basic stuff like whether the populations’ errors really were normally distributed. You’d also ask what happened to the distribution of the early population and later population when considered separately. Did the s.d. increasing in proportion to the mean or did the s.d. remain constant in absolute terms (page 6 and Fig3 suggests there is something interesting going on, but it is not pursued in any depth).
Probably beyond the first year when looking at this particular more complex dataset you might ask students to demonstrate that the assumptions such as normal distribution of errors held in the base period and if not to speculate on what might be driving this (Fig 9 suggests there is something funny going on here, perhaps an artefact of using what looks like global statistics for Jun – Aug), and then do the same for the latter period (Fig 4 upper RH graph seems to suggest there is also a problem here).
Overall this would help students to understand that if there are differences between statistics like variability and distribution when comparing data from outside the population and within it (and there are things to be done to ensure these comparisons are valid).
We know that temperatures have increased, we know that means today’s extreme events will therefore be shifted upwards relative to the past events, what we don’t know from this analysis is whether the distribution of these events has tighten around the new mean, expanded, got distorted or basically moved in proportion.
We do however know that the authors knew their results as presented were obvious from the simple facts of the data being analysed, and one can really only surmise somewhat uncharitably that the work was done for simply for political effect. Had scholarship been the aim there are a lot more interesting artifacts in this data set that warranted exploration.
I trust the peer reviewers of any journal to which it is submitted can see this too.
The problem that I have with the paper is that the analysis does not support some of the inferences. The major conclusion (stated in the abstract) is:
We conclude that extreme heat waves, such as that in Texas and Oklahoma in 2011 and Moscow in 2010, were “caused” by global warming, because their likelihood was negligible prior to the recent rapid global warming.”
The heat wave record in Adelaide Australia since 1887.shows;
Adelaide seems to be repeating 100 years ago, regarding frequency of heat waves. Heat waves have nothing to do with AGW down there.
We do however know that the authors knew their results as presented were obvious from the simple facts of the data being analysed, and one can really only surmise somewhat uncharitably that the work was done for simply for political effect.
I really can’t disagree with the gist of your argument that the work was done to favor a policy goal, but my interpretation is less uncharitable and more appreciative of the content.
In science as elsewhere, there are things that are obvious at first glance, and others that are obvious once someone points them out. You look at them and say, “I could have figured that out all by myself”, but you didn’t, and that can have significance. In the case of this paper, the geographical redistribution of temperature ranges and extremes, I would suggest, could be derived by anyone from the same starting data and statistical approach, but the geography tells us something worth knowing that would not necessarily have been appreciated if Hansen had not thought it was worth looking at. I do agree that without the geographical angle, the mere statistics would have been too trivial to bother with.
I think in a sense, this paper, which may or may not ever appear in a peer-reviewed journal, is a long interpretative editorial that asks us to think about the implications of the range of temperature extremes that different regions of the globe might anticipate with changes in mean global temperature. Whether that is a worthwhile exercise is a matter of judgment, but I wouldn’t dismiss it summarily.
I should say that I think more robust statistical analysis of the data sets we have on climate is well worthwhile. I do however think that the political agenda gets in the way of doing this properly, as this case exemplifies – the trivial has been magnified, the basics haven’t been attended to, and I suspect the really interesting stuff missed.
“I think in a sense, this paper, which may or may not ever appear in a peer-reviewed journal, is a long interpretative editorial that asks us to think about the implications of the range of temperature extremes that different regions of the globe might anticipate with changes in mean global temperature.”
That’s pure BS, Fred. Hansen is cherry-picking extreme hot weather events to scare women and children. Long interpretive editorials are not science, Fred.
Don, to be indoctrinated in the contemporary knowledge in ”climatology” is a draw-back. + YOU DON’T NEED TO BE A BIRD, TO KNOW IF THE EGG IS ROTTEN. What they preach is rotten to the last taxpayer’s $.
Fred Moolton: a long interpretative editorial that asks us to think about the implications of the range of temperature extremes that different regions of the globe might anticipate with changes in mean global temperature.
Could praise be fainter than that?
That’s like saying that it contains nothing new, since they have been trying to make us afraid of the implications of the ranges of temperature extremes in different regions of the globe for about 2 decades now.
“I wouldn’t dismiss it summarily” reads like a dismissal.
This is of no scientific value, but as a rhetorical device, it seems a bit underhanded. He’s playing the “grampa card”. People significantly younger than him can only take a statement like that at face value, not having any basis for thinking otherwise. And yet all it is is a subjective claim. I’m not as old as Hansen, but I have no such memory of cold snowy winters, though I was brought up with all manner of tales of my parents’ generation walking five miles uphill both ways in the snow to and from school every day. Until summer vacation.
Well, I became familiar with armadillos when I lived in Texas as a child. When I moved to Missouri 40 years ago, no one knew what they were; they didn’t live there because the climate was too cold. Now, they are just another variety of road-kill. So, sorry to play the grandpa card, but yeah, there are people alive who have witnessed a climate shift.
A skeptic could have done the same analysis as Hansen and presented it. It just uses temperature data. Hansen found a way to make it meaningful in terms of dice odds and 3-sigma deviations. If Texas and Russia’s heat waves were such deviations in seasonal temperature and the 3-sigma heatwave occurrence has increased more than tenfold in recent years, this is a way to attribute them with high confidence to global warming (GW). Whether the GW is AGW is a completely separate issue. This article is only about statistics. Can the skeptics use the same data to put a different spin on it? It is their turn to try.
Is 1950-1980 a cool period? I thought it was warmer than the preceding part of the century, so I can certainly believe it is at least average for the millennium.
The biggest flaw in Hansen’s analysis is that he simply cherry-picked out certain events (Texas/Russia) to prove his point. (You can “prove” anything with this approach.)
The second flaw was his attribution assumption.
The third was his silly sentence inferring that we were now at the warmest level of the entire Holocene
Face it, Jim, the whole study is not worth the paper it’s written on.
The substance is that 3-sigma warm summer events are ten times more likely now, based on statistics. This speaks for itself especially if those examples he quoted were 3-sigma events. I would like to have him list more of them, so we know what they typically look like. Apparently 10% of the land area has a 3-sigma event each summer when it used to be a few tenths of a percent. This is a good basis for evaluating summer heatwaves.
If you preselect the 3 sigma events, yeah.
There have been plenty of blog posts that do a much better job of stimulating (a) appreciation of nature and (b) efforts to understand natural climate variability.
What stands out most strongly from the paper:
The natural ~1976 climate shift. (We knew about that, but new ways of illustrating it add welcome perspective.)
What raises questions:
The missing winter versions of figures 4 & 9.
I do not know if this is strictly relevant but it seems to me that whenever one part of the world is unusually warm another part is unusually cold. At the time of the Russin heatwave was Peru not experiencing unusually cold weather? I may have got my facts wrong here but in any event I would expect a scientist to put a study of extreme heat events in the context of what was happening elsewhere in the world. How else do we gain understanding of how heat is transported around the globe? But as others have noted, Hansen’s paper is yet another political statement dressed up as science. Shame on him and shame on the scientific community for continuing to countenance such conduct. Do they not realise that it reflects badly on everyone who would call himself a scientist?
“Even accepting the statements about Antarctic ice sheets and sea level rise at face value, how does this evidence lead to a conclusion that global temperature in the first decade of the 21st century is probably already outside the Holocene range? I agree that the ‘detection’ problem should be framed in the context of climate variability over the entire Holocene, but I have not seen anyone do that convincingly”
It would be much more helpful if a scientist would make statements that actually clarify what aspects of this study they do not find realistic. It is not clear either from this comment or any previous posts and threads. I read science, as do many others. What very specifically doesn’t she like about the methodological framework (in Hansen and Sato’s Paleoclimate Implications for Human-Made Climate Change Jan 2011, which forms the framework for this one), or the evidence presented e.g. extensive sea and land surface temp reconstructions, paleoclimate date, that apparently resulted in her personal experience of being ‘thrown for a loop’ by the suggested conclusion in this individual paper? There are serious implications for deglaciation, whether or not we presently understand these implications for e.g. Greenland, or perhaps more importantly as suggested by eg. Anders Carlson’s most recent research, Antarctica.
This all raises a much more general question that needs to be addressed full-on, for a refreshing change: given how uncertain timelines for ice sheet disintegration may be, why would it not make sense to pursue emissions reductions to hedge bets over time?
While I think many of us are aware of how huge an area of uncertainty ice sheet melt is and the myriad physical constraints on estimates, outright dismissals of current climate science literature needs to be backed up with something more convincing than handwaving, no?
Unfortunately, the main support base here seems more focused on Curry’s rejection or the perception of her rejection of mitigation goals than on her ability to demonstrate anything like a cutting edge understanding of the most current science literature and related economic, development and social policy discussions. I think that’s very unfortunate and must feel unchallenging. :-(
I think confusing this paper with cutting edge advances in science is the source of your issues on this.
A typical response to someone waving at you is to wave back.
Martha: This all raises a much more general question that needs to be addressed full-on, for a refreshing change: given how uncertain timelines for ice sheet disintegration may be, why would it not make sense to pursue emissions reductions to hedge bets over time?
How much do you want to bet? The US is betting substantial amounts of money already by investing in non-fossil fuel energy, efficiency gains, and CO2 harvesting and sequestration. How much more do you want to bet on a course of action that may be totally futile?
How many threats do you want to hedge against? Other threats to civilization include the droughts and floods that will occur even if we eliminate CO2 emissions; bankruptcy of the US and EU; violent groups like the boy armies of Africa and the extreme Islamist Jihadists; emergence of new disease pathogens for humans, crops and livestock. Granted they may be uncertain, but that makes it more urgent that we act (according to some advocates of CO2 reduction.)
outright dismissals of current climate science literature needs to be backed up with something more convincing than handwaving, no?
Was there something in the feature paper that you found praiseworthy? A number of flaws were pointed out, most importantly the lack of any evidence that recent change is related to any particular causal mechanism.
Martha, I hope you have a blog of your own or someplace where you can have intelligent conversations without just talking to yourself. The denizens here are too biased to hear and understand what you are saying.
Yeah. What the stick said.
Gary M, now it’s the Climate Dice methodology, I remember when Hansen and the team used the Monte Carlo Method :-)
It is fascinating that time after time AGW promoters use terms implying deception and cheating to describe what they do. Hide the decline, load the dice, I will bet more examples will come to mind…
Writing was never one of Hansen’s strengths. Even with his freebee handlers, his phraseology is as elegant as an anvil. I mean “storms of my grandchildren”? Seriously?
It is more intriguing than anvil-like wordsmithing on Hansen’s part.
I am alluding to the self-appointed team exhibiting their scruples in their vocabulary choices.
And I’m saying that they’re coming from the same place; lack of self-awareness. A functional person would take a couple steps back and ask if saying something a good idea. A sufferer of hubris doesn’t do that.
The bigest problem I have with the study is the choice of the base period. My memory is that the period from 1951-1980 included the time when we were being warned that a new ice age was coming. That would imply that to those scientists the weather during that period was anomously cold. Thus one would expect to have more cold spells than crop up than periods either before or after. ie Hansen took a cool period and established the variance of weather patterns and defined that as “normal” to compare to other periods.
It’s disturbing how many “skeptics” try so hard to ignore the issue of the shift in the frequency distribution of temperature anomalies.
Some “skeptics” even go so far as to focus solely on the phrase “loaded dice” so they can dismiss the whole thing as “cheating”. Any excuse to ignore the subject it seems.
I can understand why. The prospect of climate change actually having an effect on the Earth is something many skeptics would like to downplay.
The only criticism I think makes sense is the AMO/PDO criticism, but that is rather a matter of crossing-fingers and hoping that can explain the shift rather than global warming itself.
The implications are as Hansen writes:
“The extreme hot tail of the distribution of temperature anomalies shifted to the right by more than +1σ in response to the global warming of about 0.5°C over the past three decades. Additional global warming in the next 50 years, if business-as-usual fossil fuel emissions continue, is expected to be at least 1°C. In that case, the further shifting of the anomaly distribution will make +3σ anomalies the norm and +5σ anomalies will be common.”
The impression I get from skeptics is that they’d rather bury the subject, even though this future of common 5-sigma anomalies is entirely possible, some people would rather this subject of study and indeed awareness of possible consequences was suppressed.
It’s also revealing how the uncertainty wrt PDO/AMO works. I don’t see anyone suggesting the real possibility that PDO/AMO might have in fact dampened the frequency shift. Well I have now mentioned it, but it’s interesting that no-one else mentioned it. It’s like everyone just wants to throw out optimistic possibilities all day and the mere existence of these should settle the issue.
Just briefly regarding the AMO/PDO “criticism”.. I don’t think it’s a criticism of Hansen’s paper (which deserves some criticisms on other grounds), because Hansen didn’t specify the causes of warming – natural vs “human-made” (his term) – other than to assign most post-1980 warming to “human-made” factors. The predominant human warming influences on temperature since 1980 have been greenhouse gases and declining anthropogenic aerosols, and their combined effect almost certainly accounts for most post-1980 warming. AMO/PDO changes may have exerted small effects, but since the warming was associated with a gain in ocean heat exceeding 10^23 joules, an internally generated AMO/PDO contribution, which entails heat transfer from the ocean to the surface and atmosphere, could not easily have been a dominant influence. There have been suggestions that elements of the AMO and/or PDO may represent external forcing (e.g., by ghgs or other modalities), but to the extent that’s true, the causal factors are then the forcings, which post-1980 have been primarily anthropogenic.
What is amazing is how studiously the believers ignore the history of the events you claim are changing so much.
But is not suprising. If beleivers would actually look at the history of the extreme weather and see the trendlines, they would no longer believe in catastrophic climate change from CO2.
And faith is more valuable than facts for most believers.
“”The impression I get from skeptics is that they’d rather bury the subject, even though this future of common 5-sigma anomalies is entirely possible, some people would rather this subject of study and indeed awareness of possible consequences was suppressed.””
Skeptics have had a gut full of possibilities backed up with questionable statistics. Hansen needs to get a grip on how many of his claimed possibilities have actually occurred over the last 20 years before he claims any more possibilities. Hansen’s possibilities, so far, have been in the realms of pseudoscience
lolwot, I agree. I also found it interesting that the winter variability is so much larger. This tends to work against the skeptics looking at examples of cold winters as evidence against global warming. Cold winters are still possible because of the wide variability in that season that hasn’t changed, and Hansen explains this interesting effect as clearly as I think is possible.
I think Hansen’s inference about Holocene temperatures relative to current and the ice sheets is something like, if it had been as warm in the past as it is now, there would have been similar losses of ice. Much of the ice structures that have been lost recently have been around for most of the Holocene, if not longer. You can look at ice shelves that have collapsed and the Pine Island Glacier for examples. The PIG has recently passed a tipping point; it would not exist if that tipping point had been crossed in the MWP. BTW, ice mass loss is accelerating.
I think Hansen cherry picked Texas and Moscow because that would be something that more people could relate to. He included all the measurements around the globe that were available in the data he presented. But, I don’t think as many Westerners remember the heat wave in say, the Amazon, as well as they remember the Texas and Moscow events. Australia and southern Europe could also have been mentioned; as well as the horn of Africa, but they are all there in the data.
I think agricultural losses are going to have more of an affect on people than the direct heat. Texas lost $5.2 billion last year. What is your annual budget for food? How many of you would that have fed? You can expect the losses to increase as the 3-sigma events increase.
Yours is an argument from ignorance (which is not necessarily the same as stupidity). In the 70’s, more media outlets may have been talking about an ice age than a warming, but more scientists were talking about a warming. Even Dr. Schneider thought we might be in for a cooling at one point, but that was because he did over-estimated the cooling affect of aerosols relative to the warming effect of CO2. BTW, he caught his mistake and retracted the paper he published on that. The rest of your argument is just wishful thinking; it didn’t happen that way.
In any case, it doesn’t matter. The baseline chosen does not change a trend, and in case you can’t see, the trend is up.
Yeah, that is not a surprise, no kidding. CO2 interacts with IR; that was a surprise 150 years ago. It reduces the flow of outbound energy; that was a surprise 100 years ago. The temperature is going up; yeah, anyone rational knows that. So, no, it is not a surprise that extreme events have increased, but it is interesting, and maybe a little surprising, to see that increase quantified.
“Yeah, that is not a surprise, no kidding. CO2 interacts with IR; that was a surprise 150 years ago. It reduces the flow of outbound energy; that was a surprise 100 years ago. The temperature is going up; yeah, anyone rational knows that. So, no, it is not a surprise that extreme events have increased, but it is interesting, and maybe a little surprising, to see that increase quantified.”
Rubbish. Where do you get the “extreme events have increased” propaganda. Extreme events have not increased.
Have you read Hansen’s paper yet? Extreme heatwaves have increased.
Adelaide SA Australia, had 12 heat waves 1890 – 1900.
Adelaide SA Australia, had 11 heat waves 2000 – 2010.
Because Hansen says it has increased in Texas that is no reason to say it has increased globally. As usual Hansen argues from the particular to the universal.
You really should look at the paper, especially Figure 3, that shows patterns of hot anomalies for various years past and present. See what you can infer about frequency from it. It is much easier with pictures like this because you can’t cherry-pick points.
Hansen rhetorical arguments often exceed the limits of his skill ie the energy inequlaities from velocity inversions of pi radians eg.
Interannual variability of surface temperature is larger in the winter hemisphere than in the summer and larger over land than over ocean (Fig. 2). The basic reason for the large winter variability is the huge difference of temperature between low latitudes and high latitudes in winter. This allows the temperature at a given place to vary by tens of degrees depending on whether the wind is from the south or north. The latitudinal temperature gradient in summer is much smaller, thus providing less drive for exchange of air masses between middle latitudes and polar regions — and when exchange occurs the effect on temperature is less than that caused by a winter ‘polar express’ of Arctic (or Antarctic) air delivered to middle latitudes.
maksimovich, I am not sure how this event can change a seasonal (3-month) average which is what Hansen is talking about, apart from which this is late spring where fronts can still be strong. Are you disputing that summer interannual variability is less than winter variability in climate? The winter variability is also stronger in the northern hemisphere due to the large continental areas where cold domes can build up before moving to other regions as a cold-air outbreak.
Hansen’s argument is that summer variability is less,ie due to a decreased gradient,and winter variability is larger due to polar outbreaks to the midlatitudes.
Infact that storm track excursions that occur is SH summer can be significant such as the NZ dec 2006 t inversion anomaly of -3c and where the upper troposphere t were the coldest on the planet (outside of the polar circles) for around 2 weeks.
As the consensus for the changes in the stormtracks (jets) is the ozone problem eg Expert assessment 2010.eg
Observations and model simulations show that the Antarctic ozone hole caused much of the observed southward shift of the Southern Hemisphere middle latitude jet in the troposphere during summer since 1980. The horizontal structure, seasonality, and amplitude of the observed trends in the Southern Hemisphere tropospheric jet are only reproducible in climate models forced with Antarctic ozone depletion. The southward shift in the tropospheric jet extends to the surface of the Earth and is linked dynamically to the ozone hole induced strengthening of the Southern Hemisphere stratospheric polar vortex.
The southward shift of the Southern Hemisphere tropospheric jet due to the ozone hole has been linked to a range of observed climate trends over Southern Hemisphere mid and high latitudes during summer.
Because of this shift, the ozone hole has contributed to robust summertime trends in surface winds, warming over the Antarctic Peninsula, and cooling over the high plateau. Other impacts of the ozone hole on surface climate have been investigated but have yet to be fully quantified. These include observed increases in sea ice area averaged
around Antarctica; a southward shift of the Southern Hemisphere storm track and associated precipitation; warming of the subsurface Southern Ocean at depths up to several hundred meters; and decreases of carbon uptake over the Southern Ocean.
The efficacy of his arguments often contradict his own propositions ie logical contradictions eg Hansen 2011.
Aerosol climate forcing today is inferred to be −1.6±0.3Wm−2, implying substantial aerosol indirect climate forcing via cloud changes. Continued failure to quantify the specific origins of this large forcing is untenable, as knowledge of changing aerosol effects is needed to
understand future climate change. We conclude that recent slowdown of ocean heat uptake was caused by a delayed rebound effect from Mount Pinatubo aerosols and a deep prolonged solar minimum.
“I think agricultural losses are going to have more of an affect on people than the direct heat. Texas lost $5.2 billion last year. What is your annual budget for food? How many of you would that have fed? You can expect the losses to increase as the 3-sigma events increase.”
Rubbish. agricultural products yield in the southern hemisphere have been at record levels in 2010/2011. We had a La Nina, cyclones and prolonged cold spells, your fear of climate change effects are laughable.
So, what you are saying is that, although there is an increasing rate of extreme heat waves, and these heat waves have been detrimental to agricultural production so far, there is no reason to believe that more events will impact agricultural levels.
I do not share your optimism.
BTW, you are aware that the Arab Spring started with food riots in Tunisia, correct? And that the Arab states are a major market for Russian wheat?
Chris: BTW, you are aware that the Arab Spring started with food riots in Tunisia, correct? And that the Arab states are a major market for Russian wheat?
Most of the N. Africa food shortage is caused by increased Chinese purchases, exacerbated by the fact that the N. African nations have not improved their per acre yields for decades.
The global food picture is complex, with California, Texas and Mexico suffering crop losses due to unusual cold snaps. Unusual cold has also hurt agriculture in Mongolia, and S. America.
“Much of the ice structures that have been lost recently have been around for most of the Holocene, if not longer. You can look at ice shelves that have collapsed and the Pine Island Glacier for examples. The PIG has recently passed a tipping point; it would not exist if that tipping point had been crossed in the MWP. BTW, ice mass loss is accelerating.”
Rubbish. Ice shelves, glaziers and sea ice have accumulated in the Antarctic over the last year. This summer season has seen so much increase in sea ice, tourists were unable to get to Mawson’s Hut.
Do you bother to examine evidence before forming an opinion?
Prince Gustav Channel collapsed 1995 – previously stable for 2,000 years
Larsen Inlet collapsed over 1989-1992
Larsen A collapsed 1995 – 4,000 years stable
Larsen B collapsed 2002 – 12,000 years stable
Muller collapsed 2009
Wilkins 1998, 2009 – at least stable for 300 years
“Observations beneath Pine Island Glacier in West Antarctica and implications for its retreat”
Or easier reading:
Arctic and Antarctic ice are declining at an accelerating rate:
If you can’t counter with actual evidence, why are you bothering to say anything at all?
Markus, you don’t seem to understand the passages you are quoting, as you are responding with irrelevant non sequiturs.
Are we to conclude from this string of comments that you admit that extreme events are increasing, ice shelves disintegrating, and agricultural losses from said extreme weather increasing? Because you haven’t provided any counterarguments, and appear to be keen to change the subject.
If you would like, quote some more unrelated facts you don’t understand; we’ll take that as a “yes.”
Robert, irrelevant non sequiturs?
My responses were to extreme events, loss of ice structures and agriculture yields. Of course it doesn’t follow that climate changes in the SH are the same as in the NH, but it does follow that if the NH warms to such a extent that extreme events are increased, then the SH extreme events must also increase, which they haven’t.
“Robert, irrelevant non sequiturs?”
Yes. Maybe if you got into the science a little more, you’d see why. None of your anecdotes were at all to the point, I’m sorry to say.
What, into the non-science of Co2 warming.
Don’t come at me with dribble, Maybe, if you got out of your bias a bit more I might consider something you say. As it is, I don’t.
What Hansen demonstrates in twelve pages is is that when the climate warms up we get more heat waves – nothing more. So what else is new? What is new is that current world temperature is outside the Holocene range. As a source for this startling information we are referred to his own book whose publication date he lists as 2012 – apparently not yet published. He also wants us to know that the sea level is now rising at the rate of 3 meters per millennium. That is almost right because that is 30 centimeters per century, not much more than 24.6 centimeters I calculated in 2008. But he wants to include the melting of Antarctic and Greenland ice sheets as part of that global warming, presumably greenhouse, that is warming the world. Here he is entirely off because Arctic warming is not greenhouse warming but is caused by currents carrying warm Gulf Stream water into the Arctic Ocean. See my article listed in Arctic Update II (December 20th). As to the Antarctic, most of its ice is in fine shape except part of the West Antarctic ice sheet which is suffering from – you guessed it – warm water melting the ice. The culprit is prevailing winds that blow away the cold water which is then replaced by warmer water from below that begins to melt the underside of the ice sheet. That West Antarctic ice sheet has been historically prone to collapse as sediments in the Ross Sea indicate. The earliest recorded collapse was during the Pleistocene, the latest only 1,500 years ago. It could happen again, but no thanks to that devil carbon dioxide. I do like Hansen’s color pictures comparing global temperatures from different time periods. It is so easy to see the distinction between 1955 to 1975 and 2006 to 2012 periods. But here I miss something, namely the period of the eighties and the nineties that he chose to leave out. Had he included that period he would have found that those years resembled 1955 to 1975 in their temperature portrait, and that the temperature rise from the twentieth to the twenty first century took very little time. I know this from having studied satellite temperature curves. They tell me that contrary to Hansen who sees a late twentieth century warming in that slot the actual temperature of this period remained the same for twenty years. That, of course, Hansen cannot let out, hence the choice of his particular temperature periods.
Arno, great catch. Hansen is writing a faux, pal reviewed op ed disguised as as a paper as a marketing push for his soon to be published latest installment of fear mongering. He should retitle Storms of my grandchildren to Trust Funds of My Grandchildren.
“Here he is entirely off because Arctic warming is not greenhouse warming but is caused by currents carrying warm Gulf Stream water into the Arctic Ocean. ”
Do you not understand that the oceans are warming because there is more energy in the system, and there is more energy in the system because an increase in CO2 has restricted the outflow?
I don’t think Arno understands that concept. I read his paper and it needs a huge amount of editing to remove subjectivity and gain coherence. Some of his paragraphs cover two pages!
Fascinating keeping up with the odd stylings of the skeptical modelers.
“That West Antarctic ice sheet has been historically prone to collapse as sediments in the Ross Sea indicate. The earliest recorded collapse was during the Pleistocene, the latest only 1,500 years ago. ”
WTH are you talking about? The WAIS contains enough ice to raise the sea level by meters. Conversely, growing the WAIS reduced sea levels by a like amount. I’m pretty sure that the sea level change since 1,500 years ago has been less than meters.
“Perceptions of climate change: the new climate dice.”
Seems to me, the clue is in the title. This is all about changing people’s perceptions, by repeating the “climate dice” meme. If they can get that one to stick, by repeating it enough, then it’ll be a great shortcut for them. No more having to do all that boring sciency stuff to try and show links between CO2 levels and extreme weather. They can just mention the “climate dice” and everyone will nod sagely.
They might nod sagely, or they might blather on about individual events while ignoring the global trend.
I hope this thread isn’t so dead that I won’t get a response to this question. I have a question about the choice of decadal time periods in this work. It seems by making this choice it’s quite difficult to get a handle on how the extra variability in the data has come about.
There are important processes in the climate system that may lead to greater variability. One that I’m thinking about is ENSO. I think it’s well known (and uncontroversial) to think of ENSO as producing a change in the way that energy in the atmosphere is distributed. If you look at an ENSO index e.g. MEI (http://www.esrl.noaa.gov/psd/enso/mei/) you can see that there has been a quite substantial change in how ENSO look between Hansen’s ‘base’ period (1950-1980) and recent decades. Not only has the sign of ENSO generally changed (from La Nina to El Nino) but also the intensity of ENSO events seems to have increased in the later period. I think an analysis on annual time scale might have given some insight into whether natural processes have contributed to the change Hansen has identified and maybe alleviated some of the concerns people have over the disconnect between the results and speculations/conclusions.
Good news and bad news….. I’m happy to give you a response……but I haven’t got a clue as to an answer :(
However ( :) ) what you say sounds very reasonable. I’ve heard that there have been many attempts to quantify changes in ENSO – and that it is pretty hard to pin down.
If you really want an answer you could bring the question up at Lucia’s Blackboard – they’re always very helpful over there. Or even send Lucia an email – if you can get her when she’s not busy.
Best of luck :)
The Pacific Decadal Oscillation (PDO) appears to have shifted back to the cool phase where La Nina events predominate. 2 Years of La Nina have cooled the Pacific but overall heat continues to be added to the oceans. Hansen and the scientists publishing on climate have a pretty good handle on this despite the wild unscientific claims made by non-scientists here. Obviously there is a high degree of uncertainty about sea level change because it involves processes affecting Antarctic glaciers that we are just beginning to understand.
”global temperature in the first decade of the 21st century is probably already outside the Holocene range, as evidenced by the fact that the Greenland and Antarctic ice sheets are losing mass rapidly”
It will need warming by 15C, before Antarctic starts losing ice, because of higher temp. There is permanent ice far north in Patagonia and in New Zealand!!! If gets warmer by 1-2-3C, common sense will say that: evaporation will increase -> therefore: ice will increase on the polar caps. Climatologist forgot from what the ice is made off…
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