CO2 sensitivity: the polar solution

by Alan Longhurst

Natural climate variability in the polar regions.

If our planet had been designed with comparative high-latitude studies in mind, it couldn’t have been better arranged than it is.

The 700N parallel encloses extensive continental regions that were once ecologically rich forest and grassland but now support agriculture, stock raising and urbanisation.   A remnant of the north polar ice-cap of past epochs lies beside a small central ocean having extensive continental shelves; these are wide open to the wind-driven passage of sun-warmed Gulf Stream and North Atlantic water through the Norwegian Sea and to a less important influx of cooler Pacific water through the Bering Straits.

But the 70oS parallel passes closely around an ice-capped continent half the size of Africa that is vegetated in only a few places, mostly by moss and lichens, and is inhabited solely by marine mammals, birds and scientists. It is surrounded by the frigid, windy Southern Ocean that isolates it from the influence of sun-warmed tropical water.

The climate of the Arctic and its small central ocean

An expressed certainty of climate science is that anomalous warming of the Arctic, to beyond historical conditions, is “on track with the Intergovernmental Panel on Climate Change’s worst-case climate warming scenario“.[1] Such comment seems singularly uninformed considering the rich information  we have concerning the changes in Arctic climate in the recent and distant past.

The development of a European civilization occurred only because of the massive flow of sun-warmed water from the North Atlantic Current into the eastern Arctic Ocean, and it has survived despite the strong and natural variability of this flow.

The consequences for the people of the northern lands of Europe and North America during future periods of reduced flow through the Norwegian Sea have not been – and will not be – comfortable: recall the call to arms of the scientific community in response to the advancing glaciers in mid-20th century because, after a 20-year progressive cooling in high northern latitudes and significant glacier advances, fears of a new glacial period were widespread.

An article in Science News suggested that ‘The unusually beneficial climate of the past few decades may be degenerating, facing humanity with a new challenge to survival’ recalling the bitter winters at the end of the 18th century, when the icy coastal waters of New York immobilised the British fleet, and the revolutionary army hunkered down in frozen fields in New Jersey.[2]   Then, in the early 1980s, glaciers began to retreat again and northern air temperature data suggested that a new warming trend had set in, so we quickly forgot about ice ages and instead stirred ourselves into action to study the potential radiative consequences of CO2 accumulation. Indeed so profound is the loss of memory that a fundamental assumption today is that northern polar regions have warmed substantially since 1900. Extraordinary surface air temperature (SAT) anomalies are reported over the Arctic Ocean of as much as 2.5-3.5oC, compared with a global mean anomaly of only 0.44oC for the same period.

But this result was based on inappropriate homogenised and gridded SAT data from all available land stations, together with surface air temperature data where these exist over the oceans.

The Arctic climate has been characterized by a millennial-scale cooling trend (of order minus 0.22oC/1000 yr) that correlates with a long period of weakening insolation since the end of the Mediaeval Warm Period and which was reinforced by feedback in higher latitudes.[3]  The Danes who settled in eastern Greenland, built decent stone houses and churches, but vanished in the 13th century when they could no longer raise crops, were victims of the changing climate which only the indigenous population was able to survive. This long period of weak solar radiation was reversed only in the final decades of the 19th century, with a renewal of warming that continues today despite the brief intermission of the 1940-60s.[4]

It is widely assumed that current reduced ice cover on the Arctic Ocean is a unique event, and perhaps some readers will think that those ships captains reports of “unheard-of temperatures” need not be taken seriously – but Norwegian oceanographers had also reported ice-free water to above 81oN, and that ‘warm Gulf Stream’ water was encountered in their profiles as far north as Spitzbergen: they suggested that this should ensure ice-free conditions there ‘for some time to come’. They also noted that “…at many points where glaciers formerly extended far into the sea they have entirely disappeared“.   Mean summer sea surface temperature at Spitzbergen had been around 3oC for 50 years prior to 1917, but by 1922 had risen to 5oC, leaving open water around the island all winter.

This regional climate shift stimulated economic changes in the northern Barents Sea – the open season for shipping coal from Spitzbergen was to lengthen from 3 to 7 months by the late 1930s.[5]   Thereafter, cooling again intervened in the Arctic and by the 1950s, very extensive ice was once again developing around Iceland, creating havoc with agriculture. At Franz Josef Land the mean surface air temperature declined during the 1960s by 3-4oC and the winter minima declined by as much as 6-10oC.

The essential Icelandic hay crops once again failed and grain crops were abandoned, while fishing off both Iceland and west Greenland faltered as cod stocks declined or migrated. This cold period in the Nordic and Arctic seas was only reversed during the late 1970s – but this time we heard no satisfaction that the region was becoming again more habitable: instead, concern was expressed that the warming was irreversible, because anthropogenic. [6]

This concern would seem to ignore the clear evidence of warm conditions in the Arctic in the more distant past, especially in the regions to the northeast of Greenland where whaling effort was concentrated in the 19th century. William Scorsby, the whaler, made regular voyages to this region and in 1811 noted that the ice barrier northeast of Greenland was breaking up: ‘I observed on my last voyage about two thousand square leagues (18,000 square miles)…between the parallels 74-80o perfectly void of ice, all of which had disappeared in the last two years’.   In 1846, on the Siberian coast, the River Lena was hard to locate in a vast flooded landscape and could be followed only by the ‘rushing of the stream’ which ‘rolled trees, moss and large masses of peat’ against a Russian survey ship, which secured from the flood ‘an elephant’s head’. [7]

It is now abundantly clear that any model of the 21st century Arctic climate must integrate the periods of warming and cooling known to have occurred in the past; it must be compatible with observations of ice cover with the 60-80 year cyclical low atmospheric pressure and warming of the northern North Atlantic (coded as the NAO) and the concurrent increased flow of warm Atlantic water into the Arctic Ocean associated with an atmospheric Low Frequency Oscillation (LFO).   This integration has not often been done in recent years, attention having shifted to the possible consequences of the radiative effects of atmospheric carbon dioxide, but the rapid reduction of ice cover in the 1990s was associated with a very active pattern of wind forcing “due to the synchronous actions of the AO and the LFO“.[8]

At millennial time scales, the progress of warm and cool periods in the Arctic can be traced with the use of proxy data. Long ice-cores from two locations on Svalbard, whose chronology can be constrained by radionuclide and oxygen isotope analysis and by sulphate and volcanic dust layers of known date, are remarkable, recording even the minor 1950-1970 cooling period.[9]   These and other multi-proxy evidence suggest that although there was a steady increase in ice-cover during the Holocene from a very low to a rather high summer coverage that peaked between 2000 and 4000 years ago, there were periods when there was sufficient open water in summer in the Canadian archipelago for Pacific and Atlantic bowhead whales to mingle, and for the Dorset and Inuit people to migrate eastwards along northern Canada.[10]

A very long and continuous proxy record from Lomonosovfonna, Svalbard (and a short one from northern Norway) has been used to demonstrate the progression of a winter cooling trend of about 0.3-0.9oC/century during more than a millennium prior to 1850, at which time there was a brief warming followed by stasis.[11]

The study of these cores has been extended using two shorter (1700-1980) ice-cores from Longyearbyen and Vardo on Svalbard whose chronology was constrained by radionuclide and oxygen isotope analysis and by sulphate and volcanic dust layers of known date, instrumental data from Vardo being used for calibration.

The changing distribution of ice cover on the Arctic Ocean during this long period of cooling has been confirmed by other proxies which give generally consistent results: reference horizons and annual-layers of oxygen and hydrogen stable isotopes in the Severnaya Zemlya ice core reveal that the cooling which reached absolute minimum temperatures in the 19th century was associated with a decline in summer insolation, and with concurrent growth of the ice cap from which the core was obtained.[12]

Further evidence is not lacking for this result: analysis of the Lomonosovfonna ice core and of timberline tree ring proxies from northern Scandinavia were used to reconstruct the evolution of ice cover in the western Nordic seas over this very long period.[13]  This “successfully explained 59% of the variance in sea ice extent during the calibration period 1864-1997” and identified less persistent periods of low sea ice in the late 13th, the early 15th, and the mid-17th centuries. The record is dominated by decadal-scale change associated with the NAO/Arctic Oscillations but the authors insisted that “the present low sea ice extent is unique” in the record and originated in a decline that started in the late 19th century after the Little Ice Age of the 17th-19th centuries.

These cores suggest that surface temperature responds to some factor that marches in step with secular change in solar intensity: it would be easy to suggest that the connection is one of simple solar warming, but that case is not made here. This long-term cooling appears to have been arctic-wide and independent of any direct consequences of solar radiation (expressed as sunspots or solar flare frequency) which took a generally opposite trend during the same period.

However, during short periods (i.e. rectangle in the sunspot figure) there was a very good match between sunspot numbers and the temperature indicated by the proxies, even though direct and sustained correlation between sun and local surface temperature is not generally to be expected: rather, the sun’s activity cycles usually impose an indirect effect on atmospheric pressure cells and wind regimes resulting in local warming and cooling. Observations of correlation between solar activity and US surface temperature showed this very clearly: west of the continental divide the correlation was negative but, east of the mountains, the correlation was positive and increased towards New England where it was maximal. [14]

This is not a unique case and similar regional relationships lie behind correlations between solar strength and the values of indices such as the North Atlantic Oscillation (NAO).   Rather than a simple, CO2-induced warming trend, records of ice-cover in the four seas that lie north of Siberia (Kara, Laptev, East Siberian and Chukchi) follow better the pattern of solar radiation; ice variability in these seas is dominated by a low-frequency oscillation of frequency 60-80 years that – in the authors words – ‘places a strong limitation on our ability to resolve long-term trends’.[15]    In any event, a stubborn positive state of the NAO characterized the final decades of the 20th century, associated with a strong pressure difference between the high and low pressure cells reduced ice coverage in the eastern Arctic significantly[16].

The 8.5 Sv of warm (6-8oC), salty, Atlantic water flowing annually through the Barents Sea continues eastward as the Circumpolar Boundary Current and is the main source of the regional surface water mass. As it goes, it is progressively modified by heat flux to the atmosphere, river run-off and melt-water in summer, and by salt-rejection during freezing. Atlantic water carries almost 100 TW heat into the eastern Arctic Ocean annually, while another 10-20 TW passes into the Arctic basin through the Bering Strait in a flow of about 0.8 Sv of Pacific Ocean water.[17]

Since 2002, this process has accelerated due to very thin spring ice and to the ‘memory of the system to the positive winter AO state that characterised the mid-1980s and 1990s’ as Stroeve et al. put it.[18]   As well, these authors note that the character of sea ice has also progressively changed after so long a period of positive NAO values, particularly in the progressive loss of multi-year ice. The single, strongly-negative NAO index during the winter of 2009/2010 was not sufficient to reverse the process.

The pulses of warm Pacific water that pass north through the Bering Straits are more variable, but the occurrence of a major incursion was confirmed in the late 1990s by observations of Pacific diatoms (Neodenticulata seminae) in Labrador Current water. This water was transported in the anticyclonic gyral circulation along the Asian continental slope through the Makarov Basin to reach the Canadian Basin as a warm anomaly of about 0.5oC. [19]

Variability in summer ice-cover in the Chukchi Sea, north of Alaska, has been correlated with the values of the AO and the NAO, and hence with the frequency of cyclonic depressions over the Arctic Ocean. During the years 1979-2009 there was an increasing frequency and strength of extreme wind events on the north coast of Alaska during late summer and autumn: mean extreme winds evolved from 7.0 to 10.5 m.sec-1 during this period. Some very strong wind events have been recorded in recent years – the August 2000 cyclone that wrecked the little town of Barrow on the north coast of Alaska included gusts that were reported at about 120 [20] Such conditions will not only hasten melting of ice formed the previous winter but, independently of that process, will also increase the apparent area of open water by rafting and compacting small, isolated ice floes.

Unfortunately, no contemporary discussion of recent Arctic conditions can ignore the furore occasioned in September 2012 as the press reacted to the news that the area of open sea in the western Arctic Ocean was larger than the previous ice minimum observed a few years earlier.   Perhaps this modern record for open water may have been the immediate effect of the passage of an exceedingly deep (970 mb) and rapidly-moving Pacific depression into the western Arctic in early August whose heavy winds fractured and dislodged the ice-pack.

Such consequences of variable wind stress in the central Arctic Ocean have been almost entirely ignored in discussions of ice loss, on the grounds that the evolution of ice cover is controlled almost entirely by air temperature and solar radiation.   Satellite imagery show that a quasi-permanent depression may migrate around the central ocean in response to boundary conditions along the Asiatic and American coasts.[21] This depression and its associated cloudiness was prominent in summer 2016 and was perhaps responsible for the fact that ice cover in mid-August of that year was relatively extensive compared with the year of minimal cover, 2012.

NOAA publishes an annual ‘Arctic Report Card’ – described as “a timely and peer-reviewed source for clear, reliable and concise environmental information on the current state of different components of the Arctic environmental system relative to historical records” – that has been astonishingly successful in convincing readers that the Arctic has warmed at almost twice the rate of the rest of the planet and that “Arctic amplification of climate change remains in full swing”.  But the Arctic Report Card takes a very generous view of the region, using 60oN as its southern limit. This parallel passes just north of Scotland and includes all of Scandinavia and the entire northern half of Siberia down to the high country of eastern Asia. Some large cities (Bergen, Oslo, Helsinki, St Petersburg and the rest) are therefore included in the instrumental data from this region.

This is an extraordinarily extensive view, extending a full 5o latitude to the south of the Arctic Circle, but NOAA are not alone in their choice: a similar pattern of Arctic temperature evolution is suggested by a Russian compilation of SAT data from almost 1500 northern hemisphere stations gridded in cells of 50 latitude x 100 longitude (left, below).

This study has been cited in an influential review as ‘some of the first evidence of the warming over the Arctic Ocean projected by models’.[22]    This conclusion is supported by a more sophisticated study (above, right) of an almost identical region that presents monthly anomaly data from 441 land stations from the Russian archives and reaches the same conclusion, while suggesting that warmer summer temperatures have dominated the change.[23]

However, the most pertinent – but largely neglected – description of how SAT has evolved over the Arctic Ocean is the compilation of Polyakov (of U. Alaska) because only very long coastal stations, mostly extending back to the 1880s, were used.[24]

The selected data represent this region very adequately (although I would have preferred the elimination of the three stations in Finland and Sweden, and of Aberdeen in Scotland); a simple pattern of SAT evolution within the arctic basin is indicated which conforms to this compilation does not support the same pattern of progressive warming as the two studies discussed above.   On the contrary, it makes perfectly clear that, on the coasts of the Arctic Ocean, the end of the century was no warmer than during the 1940s; Polyakov attributes the pattern of change to the consequences of the northern hemispheric low-frequency oscillation (LFO) in regional atmospheric pressure.

Yet another compilation of arctic data and proxies took 64oN as the limit of the Arctic region, within which 59 stations were used to analyze the pattern of regional co-variability for SAT anomalies based on PCA techniques.[25]  The most important result of this study was obtained by power-spectrum analysis of the proxies that demonstrated quasi-periodicity of 50-80 years in ice cover in the Svalbard region: at least eight previous periods of relatively low ice cover can be identified back to about 1200. This low-frequency oscillation is ubiquitous in many modern time-series of biological data from the ocean.

Collectively, these studies present two critical results. The first is that, around the shores of the Arctic Ocean and Nordic seas, surface temperatures did not reach levels equal to those of the 1930-40s even by the end of the 20th century: if any northern amplification of surface temperature exists, it stops short of the coasts of the Arctic Ocean. The second, and perhaps more important, observation cannot be avoided: that the pattern of temperature change obtained from surface observations in the ‘real’ Arctic very closely conforms to long-term persistent solar forcing. Unfortunately, when cyclical or periodic phenomena such as evident in Arctic temperatures are discussed, a solar cycle influence on surface air temperature is promptly proposed and as promptly rejected.[26]

Most of the concerns expressed concerning Arctic amplification relate to the potential effect of the loss of ice cover on the Arctic Ocean and over the northern Barents Sea so perhaps it would have been better to look first at the evolution of temperature on the ice-fields themselves, and to give less weight to data from urbanized northern parts of Europe and Asia. The data most appropriate for that task are those obtained at the drifting Russian ice-camp on the central Arctic Ocean: these record no progressive change in surface air temperature, annual means range in the rang of -17 to -20oC throughout the observing period, now unfortunately terminated.[27]

This relatively unchanging pattern of the freezing/melting seasons on the central Arctic Ocean has nevertheless been accompanied by a progressive decrease in summer ice cover on marginal Arctic seas in two areas: (i) to the east of Greenland and along the Siberian coast and (ii) north of Alaska and Canada.[28]   This has been associated with a long-term decrease in sea ice and bergs that are carried in the Labrador current to the adjacent North Atlantic, far to south of Newfoundland.[29]

In the 1960s, this flux routinely extended as far south as the coast of Nova Scotia at 45oN, was reinforced by regional freezing on the Bay of Fundy as far south as the shores of Maine.   But, since the late 1980s, these regions have been ice-free year-round.

While research papers concerning Arctic amplification continue to appear, many do not examine the regional instrumental data directly and critically, but rather base their studies on ERA reanalyses of meteorological data: a recent case is that of the use of regional data from the GMST archive to specify surface temperature in relation to the rate of retreat of ice cover; CMIP and other simulations “are accurate only in runs that have far too much global warming..this implies that the models may be getting the right sea ice retreat for the wrong reasons...”.[30]

Then, a second and perhaps more important observation cannot be avoided: that the pattern of temperature change obtained from surface observations in the ‘real Arctic’ very closely conforms to long-term persistent solar forcing. This is, of course, a direct contradiction of the results of simulation models (e.g. with the Coupled Model Intercomparison Project version 3 of IPCC4) that have been used to affirm that that increased summer ice melt observed today is forced almost directly by surface air temperatures over the ocean: “the current reduction in Arctic ice started in late 19th century consistent with the rapidly warming climate and became very pronounced over the last three decades, unmatched…last few thousand years and unexplainable by any of the known natural variabilities.” [31]

Despite such results, the above plot shows that surface temperature responds to some factor that marches in step with the progressive advance of secular change in solar intensity: it would be easy to suggest that the connection is one of simple solar warming, but that case is not made here. The author of this plot pointed out that one prime consequence of solar forcing – at least in the northern hemisphere – is to control the Equator-to-Pole surface temperature gradient. The Arctic Ocean has a unique role in modulating global climate state because of its open connection with the Atlantic Ocean, and perhaps also because of the consequences of downwelling in the Norwegian and the southern Labrador Seas.[32]

These conclusions are inconsistent with standard assumptions concerning ice loss outlined in the ‘Detection and Attribution’ chapters of IPCC Assessments, which consistently attribute ice loss to increasing air temperatures. But although everyone knows that sea water freezes only at lower temperatures than fresh water, the rather variable salinity of the surface layer of the Arctic Ocean is virtually absent from the IPCC discussion of causal mechanisms.

Seasonal cycles of vertically-integrated heat storage and of energy transport suggest that the net surface flux across the ocean’s surface is the primary driver of seasonal heat change in the Arctic Ocean.. Balance is assumed in July between incoming SW radiation and outgoing LW radiation (each about 230-240 Wm-2), and also lateral atmospheric transport of 91 Wm2. About 120 Wm-2 of SW radiation enters the ocean, which loses 10 Wm-2 of LW radiation back to the atmosphere.[33]   A net July flux of 110 Wm-2 is therefore proposed from the atmosphere into the ocean, with which is associated some ice-melt and sensible heat gain, and this is presented as the principal cause of seasonal changes in heat storage in the Arctic Ocean, dominating the 6 Wm2   accumulated from heat exchange divergence (sea/ice) and from sensible heat flux associated with Atlantic and Pacific water passing into the Arctic.

But that model ignores the consequences of incursions of warm North Atlantic water through the Norwegian Sea, well past the Arctic Circle and approaching 80oN and so on into the Barents Sea: it suggests instead that atmospheric processes dominate the heat budget.   Calculations such as those of the AR4 of the IPCC fail to answer the question before us: why is the Arctic so variable? Since the model invokes oceanic and atmospheric data only for the period 1979-2001, no data to represent the alternation of episodes of weak and strong Atlantic water influx to the Barents Sea were available to the model. In the end, it is surely misleading to approach the variability of Arctic sea ice by considering only local conditions in the Arctic Basin. Arctic variability can be understood only by emphasising that the Arctic region is wide open to the highly dynamic and variable North Atlantic current system.[34]

Yet this oceanic connection merits only brief comment in AR5: ‘Ocean circulation delivers warm water to ice sheets. Variations in wind pattern associated with the NAO….probable drivers of increasing melt at some ice margins’. This is a weak acknowledgement of the fact that the dynamics of Arctic Ocean sea ice – and so of the variability of the area and thickness of seasonal ice cover – is dominated by oscillations that are ‘associated with decadal components of the NAO/AO and multi-decadal lower frequency oscillations operating at 50-100 year. Sea ice and NAO showed a non-stationary relationship during the observational period’. [35]   Models agree that increased cyclonicity is associated with high values of the NAO and favours lighter ice conditions in the Eurasian Basin, as occurred during the period 1940-60 and again at the end of the century.[36]

In fact, observations confirm that variability in the Arctic is very largely associated with the variability in the flows through open passages to both Atlantic and Pacific Oceans, which themselves respond to the different and characteristic variability of their circulation patterns, however forced. Of the two passages, the wide-open Arctic Ocean-Nordic Seas connection is the most important and the oceanography of this region has long been a focus of research and review, so that the dominant processes are now rather well understood and quantified.[37]

Of the 8.5 Sv of warm, salty Atlantic water that passes north across the Greenland-Scotland Ridge annually, about 4.0 ±2.5 Sv passes into the Barents Sea either directly to the north of Norway as a barotropic flow, or along the western coast of Spitzbergen as a baroclinic flow. This warm water (6-8oC) carries almost 100 TW of Atlantic heat into the eastern Arctic Ocean annually, while another 10-20 TW passes into the Arctic basin through the Bering Strait in a flow of about 0.8 ±0.2 Sv of Pacific Ocean water.[38]

Because the incoming and the outgoing flows, warm and cold respectively, lie side-by-side between Greenland and Scandinavia, an asymmetry is induced in the distribution of ice-cover on the Arctic Ocean; this is generally dense to the west of Fram Strait while, to the east of Spitzbergen, much of the Barents Sea – at similar latitudes – remains ice-free even in winter under Atlantic influence.   The outgoing flow through Fram Strait and down the eastern coast of Greenland also carries with it large volumes of fresh water as fragmented pack ice, a flow that is strongly episodic at decadal scale and is associated with the series of salinity anomalies observed in the Nordic seas that were discussed earlier.

Variability in Atlantic flow into the Arctic basin is recorded in annual varves in sediment cores from the West Spitzbergen Channel, and these suggest that ‘the early-21st century temperatures of Atlantic water entering the Arctic Ocean are unprecedented over the past 2000 years and are presumably linked to the Arctic amplification of global warming’.   This proposal was very influential in moulding opinion concerning the effects of anthropogenic global warming in the Arctic, and was based on the fact that the number of sub-polar species of fossil foraminifera currently being deposited exceeds the number of polar species for the first time in the last two millennia, and that by about double.[39]

The significance of such events continues to be explored: a synthesis of circulation in the Arctic basin has been made from almost 3000 oceanographic profiles obtained in the central Arctic Ocean since the 1890s, which were not previously accessible.[40] This makes it clear to what extent the variability in the inflow of ‘warm and salty‘ North Atlantic water at times of positive values of the NAO by importing ‘vast quantities of heat‘ into the Arctic Ocean to induce core temperatures in the intermediate layer in Nansen Basin that are much warmer than in the Canadian Basin, far downstream. Canada Basin and along the Siberian coastline, where it may survive summer melting.

Transport of warm water on this scale appears to be related to the pattern of low and high pressure cells in the atmosphere. A stubborn positive state of the NAO characterised the final decades of the 20th century, and was associated with significantly reduced ice coverage in the eastern Arctic due to incursions of Atlantic water.

The first evidence that a warm pulse in 1990 had entered the Arctic Ocean was the occurrence of anomalies of order 1oC in the deep water mass of the Nansen Basin. This water was transported in the anticyclonic gyral circulation along the Asian continental slope through the Makarov Basin to reach the Canadian Basin 7 or 8 years later as a warm anomaly of about 0.5oC. A second set of slightly warmer pulses was detected at Fram Strait in 2004 followed the same trajectory as in 1990, and peak warming in the Eurasian Basin occurred in about 2007. [41] The Canadian Larsen-93 survey of the eastern Arctic explored this intrusion of warm Atlantic water whose potential temperature maximum (of 1-2oC) had by then reached far into the Laptev Sea (130oE) passing below areas of permanent polar ice cover: this was qualified as ‘a major thermohaline disturbance…now occurring in the Arctic’ by Eddie Cormack and his co-authors.[42]

Because a <50m layer of low salinity Arctic water lies directly below the ice, these deeper pulses of warm North Atlantic water are not in direct contact with the pack ice itself. But, despite microstructure observations that suggest that mixing is very weak across this halocline, heat budget estimates nevertheless yield significant vertical fluxes. These in turn suggest that decreases in ice thickness of <30 cm may be at least partially attributable to this flux, rather than to the supposed consequence of a warming atmosphere over the Arctic Ocean by the studies of Arctic SAT data that were discussed above.

The pulses of warm Pacific water that pass north through the Bering Straits are also rather variable, and the occurrence of a major incursion was confirmed by observations of Pacific diatoms (Neodenticulata seminae) in Labrador Current water in the late 1990s; following the gyral circulation of the Arctic Ocean, it is presumed that these must have passed eastwards through the Chukchi Sea and along the Canadian coasts.[43] Sea surface temperatures at the source of these fluxes in the Bering Sea have followed the now-familiar pattern of a fin de siècle repetition of the mid-20th century warming, and so they closely match the evolution of the PDO, seen here alongside change in the AMO.[44]

The significance of this observation is that it confirms that the inflow of Pacific summer water (PSW) in the late 1990s through wind forcing of near-surface transport was both unusually warm and unusually strong – as it must have been to transport Pacific organisms unusually far eastwards along the Canadian coastline and then south into the Labrador Sea.

The area of flow through the southern Canadian basin and the Chukchi Sea corresponds with the area of summer ice reduction during the late 1990s. However, increasing Bering Sea temperatures at the end of the 20th century cannot formally be correlated with relative ice loss in the Arctic Ocean, and an alternative mechanism has been proposed: that the warm pulse of PSW retards winter ice formation and so ensures a more efficient transfer of momentum from wind to the coastal water mass which ‘in turn causes an imbalance between ice growth and ice melt’. This feedback mechanism, leading to an abrupt change in coupling efficiency, is unique to ice-covered seas and may possibly dominate processes in the Arctic Ocean. [45]

Variability in summer ice-cover in the Chukchi Sea, north of Alaska, has been correlated with the values of the AO and the NAO, and hence with the frequency of cyclonic depressions over the Arctic Ocean. During the years 1979-2009 there was an increasing frequency and strength of extreme wind events on the north coast of Alaska during late summer and autumn: mean extreme winds evolved from 7.0 to 10.5 m.sec-1 during this period. Some very strong wind events have been recorded in recent years – the August 2000 cyclone that wrecked the little town of Barrow on the north coast of Alaska included gusts that were reported at about 120 [46] Such conditions will not only hasten melting of ice formed the previous winter but, independently of that process, will also increase the apparent area of open water by rafting and compacting small, isolated ice floes.

Consequences of variable wind stress in the central Arctic Ocean have been almost entirely ignored in discussions of ice loss, on the grounds that the evolution of ice cover is controlled almost entirely by air temperature and solar radiation. Yet informally-reported observations of satellite imagery show that, in at least some years, a quasi-permanent depression lies in the polar region, migrating around the central ocean in response to boundary conditions along the Asiatic and American coasts.[47] This depression and its associated cloudiness was prominent in summer 2016 and was responsible perhaps for the fact that ice cover in mid-August of that year was more extensive compared the same date in the year of minimal cover, 2012.

To summarise the arguments presented so far concerning ice-loss in the Arctic basin, at least five mechanisms must be now recognised in the absence of satisfactory evidence of anomalous warming of the surface air mass above the ice: (i) slowing of winter-ice formation, (ii) upward heat-flux from anomalously warm Atlantic water through the surface low-salinity layer below the ice, (iii) wind patterns that cause the export of anomalous amounts of drift ice through the Fram Straits and disperse pack-ice in the western basin, (iv) cloud cover associated with persistent depressions in the central ocean and (iv) the anomalous flux of warm Bering Sea water into the eastern Arctic of the mid-1990s.

These and other observations have been integrated into an oscillatory model with feedbacks and two unstable end-points that is consistent both with classical studies of past climate states, and also with recent analysis of ice dynamics in the Arctic basin by Zhakarov, whose model identifies feedback between atmosphere and ocean, both positive and negative, that interact in such a manner as to prevent long-term trends in either ice-loss or ice-gain on the Arctic Ocean to proceed to an ultimate state. [48]

The model is conceptually simple: during periods of high precipitation when winter ice forms readily, summer ice cover increases, the atmosphere cools, the Arctic front together with its associated precipitation belt shifts south so that freshwater input to the Arctic Ocean decreases, and winter ice cover is thicker, has a deeper draft, and so survives better in summer. This, in turn, shifts the Arctic front poleward again, warms the atmosphere and so completes the cycle by reinforcing the influence of the halocline of the Arctic Ocean.

This oscillatory mechanism for the control of Arctic summer ice cover, based on the changing freshwater balance of the upper layer of the Arctic Ocean, has been interpreted more recently in terms of a low-frequency climate signal that ‘propagates through a network of synchronised climate indices’ with the familiar 60-80 year Gleissburg frequency. Based entirely on observations, it has been demonstrated that the AMO signal propagates sequentially – with suitable delays – through a suite of other indices of northern climate states, culminating in an opposite-signed hemispheric signal associated with the AMO after about 30 years. This sequence has been presented in the following abbreviated form:

negative AMO→AT→NAO→NINO3.4→NPO→PDO→positive AMO [49]

This matches very closely the sequence observed: a warming regime was initiated around 1918 following a transition of the AMO from cooling to warming. In the early 1920s this was followed by the same transition in the AT and then, in about 1930 in the PDO and finally, at the end of the 1930s, a switch to a cooling regime in the Arctic that introduced a new northern hemisphere state to a warming regime that was once again initiated by a new transition in the AMO. The tempo of this sequence modulates stock-size in some important species of cold-water commercial fish, and hence the ecological state of northern seas.[50]

This sequence is logical and cyclical and appears to lie behind the alternation of bistable, alternating climate states observed in proxies during inter-stadial periods between Quaternary glaciations.

This model is surely correct in its general assessment of the critical importance of the state of the North Atlantic and of the significance of the Barents Sea connection between subtropical and polar regions, even though it has been attacked vigorously. [51]   This critical region controls climate states at scales that interest us today, supporting the argument made in the last chapter and we can no longer treat climate change in Arctic regions as a simple and direct response to anthropogenic contamination of the atmosphere, as required the standard model?

But ignoring all this, some agency reports continue to refer to the progressive loss of seasonal ice cover in the Arctic Ocean exclusively as a consequence of anthropogenic warming of the atmosphere. The NASA Goddard report on winter sea ice extent in 2016 was typical: it was ‘another record low’ attributable to record high atmospheric temperatures ‘around the globe and in the Arctic’ and to ‘warming ocean waters’: no mention is made of earlier alternation of cold, heavy-ice and warm, open-water periods.[52]  This is in line with NOAA’s annual ‘Arctic Report Card’ – described as “a timely and peer-reviewed source for clear, reliable and concise environmental information on the current state of different components of the Arctic environmental system relative to historical records” – that has been astonishingly successful in convincing readers that “The sustained transformation to a warmer, less frozen and biologically-changed Arctic remains clear“.   This document uses language suitable only to a report on the progress of a very sick patient in hospital: the progress of seven ‘Vital signs‘ are tabulated, comparing progress or regress from year to year.[53]

The attitudes of NASA and NOAA are contagious. A press report on climate research on Svalbard and in Norway described interviews with scientists then working at Longyearbyen, who talked of the recent period of sea-ice loss and glacier retreat as if it were a unique and novel event – no mention was made by them of the conditions that so impressed Captain Ingebrigsteen almost a century previously.[54]   Such a myopic view of environmental change is unfortunately very common today for reasons only too easily understood.

The continent and oceans at the bottom of the world

The Antarctic is the antithesis of the Arctic, the southern polar region being occupied by a high, continental-sized mass of ice that reaches to 5000m elevation, having depths over terrain of 2-4 kms; this ice flows coastward, especially down the valleys in the fragment of Gondwana that lies below the accumulated ice. The coastal mountain range of western Antarctica is a sector of the volcanic ‘ring-of-fire’ that surrounds the Pacific Ocean, so geothermal activity occurs along this coast and the Peninsula that stems from it.[55]

The opening of the Drake Passage during the Cenozoic isolated Antarctica and created continuity of the Southern Ocean around the bottom of the planet, radically altering ocean circulation in the southern hemisphere.[56]   Consequently, the South Atlantic basin is not an inverted mirror-image of the North Atlantic and its form ensures that sun-warmed surface water from tropical regions does not pass down the coast of South America to very high latitudes as Gulf Stream water flows up the coast of North America and on into the Arctic basin. Instead, the warm water of the Brazil Current turns eastward at 60oS within the South Atlantic gyre towards Cape Town and does not penetrate the frigid surface water mass of the Southern Ocean.

Further, some of the warm surface water that is formed in the South Atlantic is lost to that ocean when it flows into the North Atlantic basin in the North Brazil Undercurrent; this flow carries 23 Sv above 1000m “of which 16 Sv are warmer than 7oC and form the source waters of the Florida Current” later to enter the Gulf Stream .[57] This is perfectly clear in Tomczac and Godfrey’s classic figure (below) which also shows that the poleward transport of warm tropical water in the Indian Ocean is curtailed when the Agulhas Current runs out of topography at <40oS before reaching the Cape and turns eastward across the Indian Ocean. Just a few eddies of sun-warmed Aghulas water retroflect into the South Atlantic, eventually dissipating at around 300S off Argentina.

So, although sun-warmed water penetrates so far polewards in the North Atlantic that its variability controls the extent of ice cover on the Arctic Ocean, the Antarctic continent is insulated by the eastward-flowing Southern Ocean from the direct influence of water from tropical seas: nevertheless, even in winter, ice does not cover the entire ocean south of the subpolar front. This paradox has caught the attention of several research groups, which are not unanimous in their explanations: some suggest that the observations require a thermodynamic mechanism based on surface heating, while others offer a simpler explanation based on regional wind-drift of pack ice.[58]

Three ice-shelves extend out to sea from the Antarctic continent and are many times thicker than seasonal pack-ice, standing 25-50m above sea level. At their termination they fracture and release large tabular bergs that infest the Southern Ocean and were noted by the earliest navigators: their evolution is not an anthropogenic anomaly. There has been much recent concern over the fact that the Ronne-Pilchner ice shelf (lying to the east of the Peninsula) is showing signs of break-up at its termination. This ice-shelf attracted the attention of Revelle, who computed a global 70 cm rise in sea level when it disintegrates and melts.

Geothermal heat below some of the glaciers that flow onto the shelf causes intermittent changes in their flow rates, so these ice shelves cannot be entirely stable. A longer view of ice-shelf history (from a British Antarctic Survey group) concluded that regional “warming for several centuries had left ice-shelves on the NE Antarctic peninsula poised for collapse” although the effect is “comparatively modest” over West Antarctica and no significant change has been recorded for the rest of East Antarctica.

Climate of Antarctica

Regional climate conditions over the Southern Ocean are dominated by the consequences of change in the westerly winds that sweep around the continent. Sustained velocities of >14m/sec-1 are typical, so “to reach Antarctica one must cross at least 600 miles of the roughest seas in the world…no land to interfere with the west to east circulation of air…this is therefore the home of the wandering albatross…encircling the Antarctic continent perpetually”.[59]

These winds are induced between the northern side of the polar low pressure vortex and the southern side of the subtropical high pressure cells of the Indian, South Pacific and South Atlantic Oceans. Consequently, westerly wind strength around Antarctica is related to changes in the state of these cells, especially of the South Pacific high pressure cell that lies ‘upwind’ of the Antarctic peninsula. [60]

Changes in the pressure gradient along the southern border of this cell control the location and strength of wind speed around the polar vortex: these changes are coded as Southern Annular Mode (SAM) anomalies and are associated with large changes in the southern hemisphere climates of Patagonia, Australia and New Zealand and with some influence from ENSO states in low Pacific latitudes.[61]

Wind strength has increased around the polar vortex since the 1970s and consequently the SAM anomaly has taken increasingly values – and higher temperatures have been recorded on the Antarctic peninsula.[62]

This observed progression of the SAM is compatible with the consequences of the progressive destruction of stratospheric ozone by some 60-odd variants of molecules of the halocarbon refrigerants, solvents, propellants, and foam-blowing agents that we now find convenient to use. Ozone molecules are ephemeral and the presence of CFCs tips the balance towards their reduction which occurs preferentially within the two polar vortices.

In transient experiments, the evolution of polar stratospheric CFCs is predicted to take the following course in response to CFC-control measures in place or envisioned. [63]

Fortunately, we can monitor this evolution closely, because the Antarctic continent is unique in the confidence that may be placed on surface temperature data: we have direct access to 17 selected monthly mean data sets in the SCAR READER archive, maintained and edited by British Antarctic Survey – and therefore by some of those who made the observations – for research purposes: no homogenisation of the archive, and no gridding has been done. [64]

But it will be useful first to consider how we have had to proceed without this initiative of the SCAR. Our primary resource would then have been the homogenised GISTEMP data from NASA, using data in the grid boxes below. Box 71 includes parts of the Peninsula and also of Tierra del Fuego, so contains data from inhabited places, including small airports having strong terminal warming trends.   The GISTEMP gridding procedure requires that stations on the Antarctic peninsula that are within 1200 kms of these places should be homogenised with them.

Small wonder then, that Orcades Base on the South Orkney islands in Box 71 (left, below) has warmed quite strongly following the Patagonian airports. However, in Box 72, on the South Hebrides, Grytviken has perhaps been homogenised with regional SST, as the rules require in the case of isolated islands (right, below).

To add to the confusion in the classical data, note that the UK CRUTEM data for Grytviken have also been homogenised with neighbouring boxes – but in this case so as to give a sustained warming since around 1940.

It is not clear how GISTEMP homogenisation was performed on the twenty or so Antarctic stations in the four grid boxes of the final tier but this must have been done, because the GISTEMP data of each differs strongly from the original observations archived in the GHCN by NOAA. The only possible solution (more or less within the rules) would have been to treat these as islands and homogenise them with adjacent SST.

But, however it was done, this homogenisation is at least partly responsible for the RRR (Recent Regional Rapid) warming described by a team from Goddard and the British Antarctic Survey: “During the last century the temperatures of the Antarctic peninsula have risen rapidly…total increase of around 2.8oC makes this the most rapidly warming region of the Southern Hemisphere…during the past 25 years 25,000 km2 ice has been lost…etc. etc”.[65]

This appears to me to be an overstatement and the present discussion is based on unhomogenised data which are available from two sources, (i) the GHCN-all archive of NOAA and (ii) the READER archive of the Scientific Committee for Antarctic Research (SCAR). Also consulted are data from the networks of automatic weather stations (AWS) that have been deployed in Antarctica to investigate regional climate dynamics.

The present discussion is based on the SCAR READER and on the GHCN-all data of NOAA which are very close to the original data prior to inclusion in the GISTEMP archive. Also consulted are data from the networks of automatic weather stations (AWS) that have been deployed in Antarctica to investigate regional climate dynamics.  Here are READER observations for 16 stations: 6 on the peninsula, 7 on the north and east coasts, and (c) – 2 plateau stations and 1 on the west coast.  Each is plotted below together with the values of the Southern Annular Mode and, as you would expect, it is the Peninsula stations that most closely follow the wind regime in the Southern Ocean: here, the consequences of the evolution of the stratospheric ozone hole are plain for all to see.

Seven stations warmed <0.1oC/yr over a 70 -year period and the greatest warming – at Faraday/Vernadsky – reached <0.5 oC/yr or close to the IPCC estimate of global warming during the 20th century. The only other station with a similar degree of warming was its neighbour, the Rothera station which, in the GHCN-all records, is a transcription of an untidy version of the Faraday/Vernadsky data.

However, warming of the peninsula stations ceased around the turn of the century and they began gently to cool, the only exception being Orcados on the South Orkney Islands; this change of trend has been attributed to strengthened westerly winds on the Weddell Sea and in the mid-latitude jet.[66] Conditions here are very strongly influenced by regional conditions and are consistent with a reduction in the level of stratospheric CFCs discussed above. This may have occurred either as a result of control measures or perhaps naturally by change in the location, pattern and strength of the polar vortex.[67]

Temperatures recorded at Scott Base on the shores of the Ross Sea warmed progressively after the year 2000, following the trend of the two inland, higher altitude stations. But this trend perhaps requires investigation: a different pattern that lacks any progressive warming, is demonstrated by local, electronically-sensed temperature data. Soil temperatures obtained at 15 sites in the hills above Scott Base have exhibited no warming since measurements were undertaken in 1985; the data bundle from these instruments is shown below.[68] They record temperatures on the very edge of viability for microbial soil biota.

In the same region, the surface air temperature on the Ross Ice Shelf has been monitored for 35 years with an array of 13 Automatic Weather Stations. These data describe the climate that characterizes the central and coastal regions of the shelf and that of the Transantarctic Mountains: none shows any sustained trend in surface temperatures.[69]

Nor do the GHCN data for McMurdo, situated on the coast adjoining the Ross Ice shelf, support the warming pattern post-1970 at Scott Base shown by SCAR data, but rather of a shift in conditions near 1970. I can offer no comment except to note that Scott Base is currently under reconstruction.

It will be useful to review some other examples of GHCN data for Antarctica. Below (left) are GHCN data from Belgrano appropriate to the Ronne-Pilchner ice shelf; the break in the data indicates the move of the observatory to more solid ground. Despite this move, the record testifies to 70 years of regional thermal stasis. Similarly, long-term change in GHCN surface temperature at Mawson and Concordia on the east coast, facing Australia, is no more than a very slight cooling trend over a similarly long period.

Russian observations at Vostok, an inland station on the slopes of western Antarctica, suggest that progressive warming has not been observed there since 1950. Rather, these Russian observations from the GHCN-M suggest that mean annual air temperature has cooled progressively recently: the monthly plot (right, below) suggests that, for a period of 20 years, observations at Vostok were problematic, but were taken in hand around 2005: how to connect the early and recent periods is not obvious

Be that as it may, SCAR READER data show both Vostok and the Amundsen-Scott polar station warming in the final years: at the Pole, this trend (which coincided with the opening of the new station building) has been associated with changes in atmospheric circulation pattern at mid-southern latitudes, resulting from a downward shift in the Interdecadal Pacific Oscillation and therefore with increased transport of warm air from the Weddell Sea over the continent.[70]

The most urgent reports of warming come from the Peninsula, where research on the status of ground cover of lichens and moss suggests some regrowth; however, this volcanic area has surface evidence of geothermal heat, which may not to be hoped-for explanation of observations.  Such questions are currently examined by data from research stations such as Faraday that was established in the 1940’s, later transferred to the Ukraine and reopened as Vernadsky: it is reported to be one of the fastest-warming stations on Earth with a long-term change of 0.54oC/decade over the year and twice that during winter.[71]

Unfortunately, the reporting and control of the observations at Faraday prior to its transfer left something to be desired: (i) the station was moved in 1954 from the small offshore Winter Island to Galindez, closer to the coast.   Here, there were fewer extremely cold winter days after 1979 as ice cover progressively decreased on the Bellingshausen Sea, (ii) the data submitted to WMO contained several short data gaps in early years, and data for 10 years prior to the transfer to Ukraine failed to enter either the GHCN or GISTEMP, but now appear in the READER archive as plotted below, (iii), variability in the observations significantly tightened under Ukrainian management. Indeed, the data from the final 20 years appear not to be a continuation of previous observations – perhaps the instruments were placed differently after the transfer of ownership?

Yet, despite these uncertainties the GHCN archive at Vernadsky was cited in 2005 as “an extreme case, about twice” that of the overall, long-term warming trend on the Peninsula: 0.6oC annually and 1.1oC in winter semesters.  This has been associated with appropriate changes in pressure systems and the concurrent trend in the value of the Southern Annular Mode. [72] However, I would prefer not to place much confidence in the data from Vernadsky and this opinion is strengthened by finding that a fractured version of these data appears in the GHCN under the name of nearby Rothera Point.

*   *   *   *   *   *   *   *   *   *

There will be those who complain that the GHCN data used here to support the main arguments of this piece are unhomogenised, are not those used by the IPCC, and therefore that my arguments are unsupported.  And, indeed, I would be much more comfortable if we had a set of very reliable, very long-term data from a limited number of locations rationally distributed across all land surfaces and for which one could be absolutely confident that the data correctly represented progressive temperature change: the SCAR READER archive is a superb prototype for what we require.

The USA is a special case, being the largest region for which we have many long, well-managed records, numerically heavily weighted towards rural observations. The data speak for themselves: there has been no progressive warming in the USA during the last 150 years and the evolution of SAT follows very generally that of the Sun.

This demonstration is perfectly clear but almost perfectly ignored even though the patterns that can readily be observed in GHCN data from rural places do not support the standard model of a warming. planet   The Antarctic data in the READER archive have the same message for us as the US rural-dominated data – the equilibrium climate sensitivity of CO2 must be at the lower end of the discussed values: this is clear from the observations of thermal stasis except where and when the consequences of Southern Annular Mode anomalies and of stratospheric ozone depletion are significant.

It is not surprising, then, that there has been some quiet grumbling that homogenisation was not useful except for some special purposes, and was not being performed rationally, but this grumbling has been ignored by the IPCC. In his masterly Critical Review of Surface Temperature Data Products‘, Ross McKittrick addressed this issue head-on by comparing all pairs of raw and adjusted GISTEMP data in grid-cells in which both are present; he found that until about 1980, the adjustments resulted in a temperature cooler than the observations, but in later years corrections tended to be in the opposite sense. The consequence is that ‘a portion of the warming trend shown in global records derived from the adjusted GHCN archive results from the adjustments and not from the underlying data’.

The unavoidable consequence is that ‘a portion of the warming trend shown in global records derived from the adjusted GHCN archive results from the adjustments and not from the underlying data’. These adjustments increase the 20th century warming by 0.3-0.40C and this warming is now widely assumed to be real.[73] Others have, of course, investigated this , at least informally, and have come to the opposite conclusion.

In June 2016 the Goddard Station Selector facility was modified so that the individual GHCNv3 data were shown in four states: colour-coded as submitted, as adjusted, as cleaned and as homogenised.[74]   For a time, this enabled click-by-click verification of McKittrick’s results (a different colour line for each of 4 steps in the homogenisation), and this abundantly confirmed his results – but now you can click as hard as you like, but only the final homogenised plot is shown. The others sleep soundly, all of them…

So climate change research proceeds profitably using a debased currency managed by two US governments agencies. But there’ll be a bill to be paid for that one day in shuttered university departments and government agencies…..

Alan Longhurst

Cajarc, France

January-February, 2021

[ References  ]

JC note:  Alan Longhurst’s previous posts at Climate Etc. can be found [here].  As with all guest posts, please keep your comments civil and relevant.

108 responses to “CO2 sensitivity: the polar solution

  1. The UAH data 1979 to 2020 also show exceptionally high warming rates for the north polar region and pretty much flat with no warming in the south polar region

    As for ice melt in the Arctic region, I don’t think it can be understood purely in atmospheric terms because the region is geoligically active. I will post the link later if that’s ok.

  2. Thank you for the much needed subject. I read with interest upto “The Danes who settled in eastern Greenland.. This long period of weak solar radiation was reversed only in the..”

    It’s pure speculation that the abrupt climate change in Greenland circa 1000CE and subsequent cold conditions was due to changes in insolation. Other climate change drivers are available.

    (Also I thought Eric the Red and his entourage settled in south west Greenland)

  3. Reblogged this on Climate Collections.

  4. The NASA GRACE-FO satellites says we are loosing hundreds of gigatons of ice from glaciers and the poles every year and the trend is accelerating. Oh If our problems were so simple as to just pin all our problems on one molecule when we are spewing hundreds of tons of other non condensing gases into the biosphere every year. The rapid growth of ocean dead zones is stark evidence of our careless geoengineering.
    It’s just a coincidence that a giant iceberg, more than 20 times the size of Manhattan, just split off from Antarctica’s Brunt Ice Shelf this week.

    But just so this isn’t just your typical pearl clutching rant I just read the Russian’s set a new record for sending a LNG cargo ship across the north pole.
    “FEBRUARY 23, 2021 / 10:33 AM / CBS NEWS
    The LNG (liquefied natural gas) tanker set out from the Chinese port of Jiangsu on January 27 after delivering its cargo. It entered the Northern Sea Route, which traverses Russia’s north coast, a few days later near Cape Dezhnev, where it was met by the Russian nuclear icebreaker 50 Let Pobedy (50 Years of Victory). Together they completed the 2,500-nautical-mile voyage through the ice in 11 days and 10 hours.”

    • I think one point of the post is historical events must be taken into account, not just the past 10 years or whatever modern data set one chooses.

  5. One of the reasons the general public is so ignorant about the fraud of “global warming” is a lack of concise information. Is there a place where this information can be found in condensed form that would be understandable and not go on forever with details that may be critical for researchers but not to educate the vast unwashed?

  6. “a second and perhaps more important observation cannot be avoided: that the pattern of temperature change obtained from surface observations in the ‘real Arctic’ very closely conforms to long-term persistent solar forcing.”

    Um, the observation that shows the opposite has been neatly clipped of the end of the graph.

    • I would appreciate a link to the whole chart if you have one. Thanks.

    • Message from Alan Longhurst:

      The original is at V.F. Radionov (1997) APL-UW-Tech Rpt fig 32 lower part. I copied and pasted, nothing is clipped

  7. An excellent paper which deserves wide circulation.

  8. This is a most interesting paper and worth studying in detail. At this stage, I just want to offer a correction. On the second page it says: The Danes who settled in eastern Greenland……..but vanished in the 13th century. Firstly, no Danes settled in Greenland in the late 9th century. Eric the Red came from Iceland (after being banished from Norway). After discovering Greenland, he encouraged Icelanders to come to Greenland, where they would find plenty of arable land, suitable for sheep farming. A lot of Icelanders took his advise and settled in the western coastal regions of Greenland (not in the east). According to our historical annals, well documented, the last certain contact with the Icelandic settlement was in the early 15th century. A group of Icelanders sailed from Greenland to Iceland in 1410, after having spent 4 years in the Icelandic colony there.

  9. Pingback: CO2 sensitivity: the polar solution – Watts Up With That?

  10. Pingback: CO2 sensitivity: the polar solution – Climate-

  11. Pingback: CO2 sensitivity: the polar solution |

  12. Matthew R Marler

    Alan Longhurst, thank you for the essay.

  13. Pingback: CO2 sensitivity: the polar solution – Climate-

  14. The Earth system is a turbulent fluid flow problem governed by a nonlinear set of partial differential equations – if they were solvable. The flow of atmosphere and oceans are fractal – there is a continuum from moments to aeons and from micro eddies to planetary waves. Patterns form and shift in the spatio-temporal dissipative chaos of a nonequilibrium thermodynamic system. Extremes can be very extreme, regimes very persistent and shifts abrupt. It is the nature of Wally Broecker’s dynamically complex beast – at which we are poking sticks. Let’s start with a cartoon.

    The flip flops in flow patterns are seen in physical indices and geophysical series by which these things are measured. It was dubbed Hurst-Kolmogorov stochastic dynamics by Dimitris Koutsoyiannis to emphasis the importance of physical evidence contrasted to merely theories of dynamical systems. The causes are cryptic but they feedback into thermohaline circulation and ice sheets. It may be as simple as minor power components of the sun’s output in UV or solar wind modulating polar surface pressure and the great zonal atmospheric seesaw of the polar vortices. The latest cool Pacific Ocean climate shift in 1998/2001 is linked to increased flow in the north (Di Lorenzo et al, 2008) and the south (Roemmich et al, 2007, Qiu, Bo et al 2006) Pacific Ocean gyres. Roemmich et al (2007) suggest that mid-latitude gyres in all of the oceans are influenced by decadal variability in the Southern and Northern Annular Modes (SAM and NAM respectively) as wind driven currents in baroclinic oceans (Sverdrup, 1947).

    Focussing in on the Arctic and current conditions. Igor Polyakov is not to be taken lightly. Are we seeing a state change (in the sense of chaotic attractors) in the Arctic? And what might it shift to?

    “This synthesis study assesses recent changes of Arctic Ocean physical parameters using a unique collection of observations from the 2000s and places them in the context of long-term climate trends and variability. Our analysis demonstrates that the 2000s were an exceptional decade with extraordinary upper Arctic Ocean freshening and intermediate Atlantic water warming. We note that the Arctic Ocean is characterized by large amplitude multi-decadal variability in addition to a long-term trend, making the link of observed changes to climate drivers problematic. However, the exceptional magnitude of recent high-latitude changes (not only oceanic, but also ice and atmospheric) strongly suggests that these recent changes signify a potentially irreversible shift of the Arctic Ocean to a new climate state.”

    Dynamical systems theory suggests that the system is pushed by greenhouse gas changes and warming – as well as solar intensity and Earth orbital eccentricities – past a threshold at which stage the atmosphere, biosphere, cryosphere, hydrosphere and lithosphere — each of which has distinct characteristic times, from days and weeks to centuries and millennia – interact in multiple and changing negative and positive feedbacks as tremendous energies cascade through powerful subsystems. Into multiple equilibrium states. Some of these changes have a regularity within broad limits and the planet responds with a broad regularity in changes of ice, cloud, Atlantic thermohaline circulation and ocean and atmospheric circulation.

    The US National Academy of Sciences (NAS) defined abrupt climate change as a new climate paradigm as long ago as 2002. A paradigm in the scientific sense is a theory that explains observations. A new science paradigm is one that better explains data – in this case climate data – than the old theory. The new theory says that climate change occurs as discrete jumps in the system. Climate is more like a kaleidoscope – shake it up and a new pattern emerges – than a control knob with a predictable gain.

    • On the subject of the alleged global warming caused by the greenhouse effect consider the following please. As you well know, R is the constant in the equation of state. R is the temperature reaction to heating of a unit amount of an ideal gas. Gases in our atmosphere have similar reactions to heating and the basis of comparison is each gas’s R-value. These values are known to vary due to experimental error.

      The greenhouse gas theory claims when non-greenhouse gases are replaced by greenhouse gases the average surface temperature in Earth’s troposphere is raised. In other words, the reaction to heating by greenhouse gases versus non-greenhouse gases is more energy efficient in terms of temperature. To wit, greenhouse gases take less energy to create the same temperature response. This claim can be turned into a proposition in terms of the kinetic theory of heat. The greenhouse theory holds the R-values for greenhouse gases must be significantly lower than those for the non-greenhouse gases. The null hypothesis is, of course, that all gases have the same R-value.

      Experimentally we can find the R-values for each gas by three parameters, Cp, or the specific heat at constant pressure Cv, or the specific heat at constant volume and M the molar mass. Now, Mayer’s relation tells us a gas’ R-value is found by the formula ( Cp – Cv )· M. The data for experimental R-values on two gases oxygen and, carbon dioxide are revealing. The ( Cp – Cv ) values for oxygen and carbon dioxide are respectively 0.2598 and 0.1889. Their molecular weights, M are 31.999 and 44.010 respectively. Their products are the R-values for each gas and reflect their response to heating from sunlight or any other energy source. Those R-values are 8.3133402 and 8.313489 and when rounded to four place accuracy are both the same value 8.313. In other words, their response to heating is virtually identical. The other four major constituents of our troposphere, methane, water vapor, nitrogen and argon are very similar with R-values of respectively 8.3150869, 8.3139225, 8.3142584, and 8.3131788. The differences are trivial. This implies the null hypothesis is not rejected, the gases all have the same response to heating within experimental error. The prospect that there exists a useful distinction between greenhouse gases and non-greenhouse gases is very unlikely.

      The source for my data comes from Claus Borgnakke and Richard W. Sonntag, Fundamentals of Thermodynamics, 8th Edition, (New York: John Wiley & Sons, 2013), p. 760, Table A.5. The data reflect the properties of these gases at 250 C, 100 kPa and are in SI units. The experimental error is about 0.02% at this temperature and pressure, which are close to the average temperature and pressure at Earth’s surface in its troposphere.

      Similar results have been found by Robert Ian Holmes using planetary data, especially the planet Venus whose atmosphere is 96.5% carbon dioxide. See Holmes, R.I. (2018). Thermal Enhancement on Planetary Bodies and the Relevance of the Molar-Mass Version of the Ideal Gas Law to the Null Hypothesis of Climate Change, Earth Sciences, 7(3), 121. Holmes found no support for the alleged “greenhouse effect” operating on that planet.

      • You need to learn something about quantum mechanics.

      • Here’s the link to the work of Australian atmospheric scientist Robert I. Holmes:
        The present hypothesis of climate assumes – without empirical evidence – that there is a tropospheric greenhouse effect (GHE); meaning an anomalous net warming from greenhouse gases like CO2. This effect supposedly causes significant net warming in the troposphere – even though this hypothetical warming has never actually been empirically measured, quantified and then attributed to GHG in any published, peer-reviewed scientific study to date.

      • Here’s a refutation of Carl Sagan’s “runaway greenhouse effect” on Venus:
        How did such bad science become “common knowledge?” The greenhouse effect can not be the cause of the high temperatures on Venus. “Group Think” at it’s worst, and I am embarrassed to admit that I blindly accepted it for decades.

      • You need to be able and willing to distinguish between reputable and disreputable sources.

      • “You need to be able and willing to distinguish between reputable and disreputable sources.” – RIE

        They would have said that sort of thing in 1543 after Copernicus suggested the Sun was centre of the solar system and not the Earth.

        It’s the high pressure of Venus’s thick dense atmosphere which keeps the surface so hot. The concept of a mega nucleic density impactor creating the voluminous outgassing of CO2 on Venus is analogous to the lesser events of the ~66mya extinction event & antipodal Deccan Traps, as well as the ~250mya extinction event & antipodal Siberian Traps.

        You need to be able to think out of the groupthink box.

      • Another mystery of Venus, not just what caused the mega outgassing of CO2 event, is why hasn’t the atmosphere leaked out into space if it happened around 700mya?

        It suggests the atmosphere is being replaced continually due to high inner core activity. Either the event was a lot more recent than calculated or (imo) the nucleic density impactor perhaps exitted the planet at a much lower velocity, creating a ‘dark moon’. This unseen satellite would stir the inner core of Venus due to a *strong* gravitational interaction. A continuous high level of volcanism is what keeps the surface so hot.

      • There are two small mistakes in my article. The first is a typo in the sources area. The table of gases given in the text I refer to says the measurements were taken at 25 degrees Centigrade, not 250 degrees Centigrade as in my original text. The second is in the reference to Robert Ian Holmes article. I had it as being on a single page 121, when it actually spans the pages 107 to 123.

      • On March 3, 2021 Robert I. Ellison said, “You need to learn something about quantum mechanics.”

        Robert I. Ellison, you are mistaken, sir. Your argument is with the authors of the thermodynamics textbook I used as a recent source, not me, about quantum mechanics. I am merely using their facts to back up my test of this proposition. Recall, I quoted the authors’ claim the data which I used as a source is accurate to 0.02%. Your dispute, then, on their claim to accuracy. I am merely reporting what these experts claim.

        Now, can you quote studies which show that this data the authors presented is in error in point of fact? If it is in error, it is widespread and needs to halted. I have seen data like what I presented dating back to the 1950s. If so, things have been wrong for a long time. On the other hand, this text was well wrung out by 24 physicists named in the preface. If what you claim is true, Robert, don’t you think these experts would be well aware of a test using quantum mechanics had appeared and its revolutionary implications for the kinetic theory of heat? Do you know something they do not about quantum mechanical tests of the kinetic theory of heat that bear on R-values? If so, please inform them and us.

      • On March 3, 2021 Alan Lowey said, “Here’s a refutation of Carl Sagan’s “runaway greenhouse effect” on Venus…”

        Many thanks for what proved to be a very interesting article from 2010. I read it with great interest. It was both provocative and humorous. You may find of interest an equally provocative article I referenced in my essay by Robert Ian Holmes on Venus and the other planets. Holmes rummages through many areas of science and its history and the journey is fascinating. I was impressed with the result. I’d be interested on your take on it as would others on Dr. Curry’s website.

        Kind regards, Mathlete

      • There are many versions of sky dragon slaying theories. I have no more time for any of them. This is not a matter of groupthink – but of being attentive to more real science.

        Before departing from scientific paradigms you need to understand the basic mechanisms. Hence my mention of quantum mechanics in an open, dissipative. nonequilibrium thermodynamic system. In which the statistical thermodynamics of the ideal gas law in a closed system is not fundamental.

  15. Not so sure I would take much stock of forecasts of abrupt dire and irreversible climate changes, as ascertained from mathematical models that are well over the tips of their skis. Abrupt changes may occur, but we are not in a position to make accurate forecasts as to when or why. If it happens, we will have to adapt. No reason to panic.

    • Climate surprises are inevitable – and that is based on observations and not models. A risk management framework suggests adoption of a pragmatic strategy (that) centers on efforts to accelerate energy innovation, build resilience to extreme weather, and pursue no regrets pollution reduction measures — three efforts that each have their own diverse justifications independent of their benefits for climate mitigation and adaptation.”,for%20climate%20mitigation%20and%20adaptation.

      That we are pushing planetary boundaries is obvious enough.

      The answer is to build prosperous and resilient communities in the 21st century. The soil carbon store can be renewed by restoring land. Holding back water in sand dams, terraces and swales, conserving and restoring forests, wetlands and rangelands, reclaiming deserts, changing grazing management, encouraging perennial vegetation cover, precise applications of chemicals and nutrients and adoption of other management practices that create positive carbon and nutrient budgets and optimal soil temperature and moisture. Atmospheric carbon is transferred from the atmosphere to soil carbon stores through plant photosynthesis and subsequent formation of secondary carbonates. The rate of soil carbon sequestration ranges from about 100 to 1000 kg per hectare per year as humus and 5 to 15 kg per hectare per year inorganic carbon. The near term potential for carbon sequestration in agricultural soils is approximately equal to the historic carbon loss of 80 GtC during the modern era. This is about 10 years of global annual greenhouse gas emissions. At realistic rates of sequestration 25% of current annual global greenhouse gas emissions could be sequestered over 40 years. In the longer term soil scientist Rattan Lal puts the sequestration potential at the carbon content of 157 ppm of atmospheric CO2 by 2100.

      Carbon sequestration in soils has major benefits in addition to offsetting anthropogenic emissions from fossil fuel combustion, land use conversion, soil cultivation, continuous grazing and cement and steel manufacturing. Restoring soil carbon stores increases agronomic productivity and enhances global food security. Increasing the soil organic content enhances water holding capacity and creates a more drought tolerant agriculture – with less downstream flooding. There is a critical level of soil carbon that is essential to maximising the effectiveness of water and nutrient inputs. Global food security, especially for countries with fragile soils and harsh climate such as in sub-Saharan Africa and South Asia, cannot be achieved without improving soil quality through an increase in soil organic content. Wildlife flourishes on restored grazing land helping to halt biodiversity loss. Reversing soil carbon loss is a new green revolution where conventional agriculture is hitting a productivity barrier with exhausted soils and increasingly expensive inputs.

      Increased agricultural productivity, increased downstream processing and access to markets build local economies and global wealth. Economic growth provides resources for solving problems – conserving and restoring ecosystems, better sanitation and safer water, better health and education, updating the diesel fleet and other productive assets to emit less black carbon and reduce the health and environmental impacts, developing better and cheaper ways of producing electricity, replacing cooking with wood and dung with better ways of preparing food thus avoiding respiratory disease and again reducing black carbon emissions. A global program of agricultural soils restoration – as emerged in Paris in 2016 – is the foundation for balancing the human ecology.

      I have heard this argument of blindly, ignorantly and unnecessarily going down a path not knowing where it leads enough to be simply dismissive of it. In this the decade of water and the decade of ecological restoration – the world at large is hungry for a different narrative. One in which intransigent contrarian hand waving is utterly irrelevant.

  16. ‘ … the sun’s activity cycles usually impose an indirect effect on atmospheric pressure cells and wind regimes resulting in local warming and cooling.’

    Such as blocking caused by a meandering jetstream, which only happens when the sun is quiet.

  17. Very nice article. The author has taken a subject of extreme complexity and provided a comprehensive and coherent summary of the dynamics involved.

    I note Mr Longhurst’s long and distinguished career. I always enjoy the views of those who probably don’t have to worry about potential sanctions and ostracism from their colleagues. Somehow, discussing truths is not so threatening. Funny how that works.

  18. Richard Swarthout

    To All and hopefully including Tony Brown,

    As I age clear thinking fades, so the article was difficult for me to follow, although I did get the main points. However I am left with questions prompted but not directly related to the article.

    1. The article and some of the comments use the term “global warming”, however mainstream consensus herd has now changed that term to “climate change”. Apparently CO2 emissions can now be held responsible for both temperature increases and decreases. Is there a simple explanation? Surely it is based on science.

    2. I recall statements that long term changes in temperature are preceded by a sudden and severe event. Please discuss this.

    3. Regarding the LIA, was it preceded by a sudden and severe event? Can it happen again? And of note, it did occurred prior to the industrial revolution.


    • Richard

      Sorry, only just saw your message.
      Great to hear from you. Hope you and your family are well?

      Its a great question but time tends to obfuscate things, as whilst we are pretty good at picking up trends, for example a deterioration of weather over a decade, it is less easy to pick up on extreme one off events and say they had a profound effect on changing the climate.

      Michael Mann believed it was volcanic activity around 1258 that set the scene for the cold that followed, but my own records show we had cold weather before and cold weather after wards .

      There was an extreme rain event lasting two years around 1315 that seem to have ushered in a substantial period of cold and I have written here before that we have written records from our local abbey that the cloisters had to be enclosed and fireplaces created and windows made smaller as the cold became more persistent through the 1300’s.

      I believe this was mostly down to a change in wind direction to a colder winter easterly, rather than the warmer westerlies we normally experience.

      However, if you remember my article ‘ the intermittent little ice age’ it seems the cold came in waves and was interspersed with much milder weather.

      So the question is broadened to what events precipitated the extended decades long cold, and then what other events then caused the weather to warm up again as even the harshest winter could have a hot summer.

      I have Hubert lambs record of winds back to the 1400’s and my inclination is to think that extended periods of changed wind direction caused the cold and warm weather, no doubt helped by the oceanic currents being warmer or colder than average

      Why they changed to a consistently different direction is another matter entirely

      • Richard Swarthout

        Thank you Tony. I am well. For an 80 year old I am doing extremely well. My daughter and two granddaughters live next door and the dote on me and that helps; the 18 year old changed her mind about being a zookeeper and going to England for her training and so we gave up on going over for the Plymouth celebrations. I hope you are well also.

      • Tonyb A suggestion: look far afield and find correlations, events to climate.
        Eddy cycle events
        Ascendance(at peaks):
        Akkad/Sumer 2700bce (+Harappan)
        Agean 1750bce
        Phoenico/Greek 800bce

        Collapse (at root)
        Akkad/Sumer 2200bce (4k2 event)
        Agean 1300bce (sea people)
        Phoen/Greek 300bce (earthquakes Helike)
        Temple period 3200bce

        Match to here:

      • “However, if you remember my article ‘ the intermittent little ice age’ it seems the cold came in waves and was interspersed with much milder weather.” – Tony

        An increase in tidal forcing can explain it. More energy pushed up to higher latitudes enters the stratospheric polar vortex. This rotating frigid air then gets released periodically into the lower jet stream, which increases it’s reach in meandering bends. This is what’s recently happened in Texas and analogous to the infamous weather phenomena referred as the Little Ice Age.

      • Alan

        Here is a link to the article

        It was not a monolithic deep freeze for 500 years but a general cool spell that came in waves and was mitigated at times by perfectly ‘normal’ conditions .

        No doubt lots of related causes, but a change in wind direction, polar vortex, currents, jet streams, all had their place


      • melitamegalithic

        Not disagreeing with anything you say. Now all we need is lots of grant money to fund a 2 year study and we might begin to get to the bottom of it.


      • Thanks for the link Tony.

        “The present does not look so very different to other points of the period surveyed in this paper, with several notable periods of warmth and widespread heat-waves and droughts comparable to the modern era.” – Tonyb

        I agree that the Little Ice Age is an unfortunate misnomer. I wish to stress that it should be considered in the context of the previous warming of Greenland, the millenial cycle, Heinrich events and ice age theory.

        The climate is ultimately a Theory of Everything.

      • Tonyb
        I was told at one time, that if I was to seek funds, I really needed good contacts, not a good reason. Alas.
        Re weather/climate, In the Eddy cycle we are heading to peak warming, same/similar to RWP, but things might also be beginning to change. I remember long ago, about half a century, tasting the first fruit – medlars- at about April (they tasted very nice on end of lent fasting). This year it was at early February. That, and increase in drought or lack of enough rain, has been gradual over the years. It is noticeable.
        As to Eddy roots (LIA), the ‘cold period’ the more revealing is the effect on people; mainly the famines. Link:

  19. “In any event, a stubborn positive state of the NAO characterized the final decades of the 20th century, associated with a strong pressure difference between the high and low pressure cells reduced ice coverage in the eastern Arctic significantly.”

    It was the negative NAO in 1993 and 1995-1999 which was also driving the AMO warming which significantly reduced the sea ice. Negative NAO increases warm humidity events and cyclones into the Arctic, like in summers 2007 and 2012. Negative NAO is also directly associated with slower trade winds, and there is a positive feedback from El Nino episodes to major AMO warm pulses with around an 8 month lag.

    “Rather than a simple, CO2-induced warming trend, records of ice-cover in the four seas that lie north of Siberia (Kara, Laptev, East Siberian and Chukchi) follow better the pattern of solar radiation; ice variability in these seas is dominated by a low-frequency oscillation of frequency 60-80 years that – in the authors words – ‘places a strong limitation on our ability to resolve long-term trends’”

    AMO variability is an inverse response to changes in solar wind temperature/pressure, with weaker solar wind states causing negative NAO/AO conditions, driving a warmer AMO. The early to mid 1970’s had the strongest solar wind states of the space age, followed by the mid 1980’s and early 1990’s, during the three colder AMO anomalies. All with positive NAO/AO regimes. The rapid AMO warming from the mid 1990’s corresponds to weaker solar wind states since then.

    Once upon a time they admitted that the models didn’t predict the rapid post 1995 warming of the Arctic. Which is hardly surprising when the model consensus is that rising CO2 forcing increases positive NAO/AO conditions. That won’t shift the AMO to its warm phase.

  20. So in 1811 William Scorsby saw the ice breaking up, and in 1815-1817 British naval ships observed a great loss of sea ice. Right in the coldest decade of the Dalton Minimum for Europe. The late 1800’s Gleissberg solar minimum had a warm AMO phase, and here we are in a new centennial solar minimum with a warm AMO phase again. Tony Heller found a story of Danish ships sailing far into the Arctic in the 1120’s. That was a particularly cold centennial solar minimum for the mid latitudes, according to weather chronicles from Michael the Syrian and James A. Marusek, and Esper 2014. But just look at the scale of the warm SST proxy by southeast Greenland during the Oort solar minimum:

  21. “This oscillatory mechanism for the control of Arctic summer ice cover, based on the changing freshwater balance of the upper layer of the Arctic Ocean, has been interpreted more recently in terms of a low-frequency climate signal that ‘propagates through a network of synchronised climate indices’ with the familiar 60-80 year Gleissburg frequency.”

    The Gleissberg cycle varies from 80-130 years, it is just another name for centennial solar minima frequency. The last two AMO envelopes were close to 60 and then 70 years, with the full 130 years being constrained by the timing of the late 1800’s centennial solar minimum, and the current centennial solar minimum. So why the warm AMO phase from 1925? there must have been weaker solar wind states causing enough negative NAO/AO conditions.

    • “So why the warm AMO phase from 1925? there must have been weaker solar wind states causing enough negative NAO/AO conditions.” – Ulric

      What’s the causal link between solar sunspot minimums and Earth’s climate change in your opinion? There’s no clear connection in the scientific literature.

      • Solar Forcing of Regional Climate Change During the Maunder Minimum
        Drew T. Shindell, Gavin A. Schmidt, Michael E. Mann, David Rind, Anne Waple
        “Modeled surface temperature changes show alternating warm oceans and cold continents at NH mid-latitudes”

      • Changes in solar energy output due to sunspot variation is very small and *not* a good model for climate change here on Earth.

        It’s the reason why this paper in Nature was recently retracted:

      • I have referred to the solar wind variability and not to sunspot numbers.

      • “I have referred to the solar wind variability and not to sunspot numbers.” – Ulric

        Can you provide a link to a scientific paper which shows solar wind variability is a driver of climate change?

        I did a quick search and found this refutation:
        With no discernable increase in solar activity, proponents of solar influence on modern warming have turned to other possible explanations. One that has gained traction in recent years is the idea that galactic cosmic rays may play a role in the Earth’s climate.

        Galactic cosmic rays (GCRs) are high energy particles from beyond our solar system that regularly bombard the Earth. When solar activity is high, the “solar wind” – a stream of particles emitted from the sun – acts to reduce the number of GCRs that enter the Earth’s atmosphere.

        Some research has found that GCRs in the atmosphere can play a role in cloud formation, with higher levels of GCRs potentially leading to more low-altitude clouds. These low-altitude clouds can influence the Earth’s climate by reflecting incoming sunlight back into space.

        This has led some to suggest that changes in solar activity could influence the Earth’s climate by changing cloud formation.

        However, the GCR hypothesis suffers from the same fundamental problem as total solar irradiance: it is moving in the wrong direction.

      • Furthermore the CLOUB experiment at CERN which was specifically set up to test Svensmark’s hypothesis has discounted a role of GCR in climate change.
        Dunne et al. used the CLOUD (Cosmics Leaving Outdoor Droplets) chamber at CERN to construct a model of aerosol formation based on laboratory-measured nucleation rates. They found that nearly all nucleation involves either ammonia or biogenic organic compounds. Furthermore, in the present-day atmosphere, cosmic ray intensity cannot meaningfully affect climate via nucleation.

      • Ulric Lyons

        Alan, you had quoted me and then changed the subject twice, the solar wind influence on the NAO/AO, not on GCR’s.

  22. The global variations in temperature are negatively correlated with the state of the AMO. Early 20th century warming, midcentury cooling, late century warming and the hiatus. Figure 2 shows wind in white and currents in black during these same warm and cool phases. In warm phases the polar annular modes are more zonal – more positive SAM an NAM with lower polar surface pressure. In cool planet phases north and south Pacific Ocean Gyres spin up with more meridional polar modes facilitating upwelling in the eastern Pacific and cool phases of the Pacific decadal variation. Planetary energy dynamics ae modulated by cloud changes in the Pacific tropics and subtropics anti-correlated with sea surface temperature.

    The third graph is numbers. The AMO (blue) obviously correlated with an accumulated NAO index (green) and seemingly but logically AMOC (red) based on limited measurement at the 26 degree north array. .
    Figure 1 – AMO
    Figure 2 – the gyre hypothesis –
    Figure 3 – physical observations –

    Polar indices are as dynamic as the atmosphere itself on scales of moments to millennia. It is impossible to eyeball specific links to Earth climate. But there may be a link between the NAO and UV, solar winds or the global electrical circuit somewhere in there. The accumulated NAO index shows a bias to one state or another influencing AMOC and thus the AMO.


  23. Slightly off topic, but has anybody noticed the extraordinary decline in arctic sea ice over the last week or so? I hope its a measurment error because its just incredible .

  24. “Meteorological effects resulting from fluctuations in the solar wind are presently poorly represented in atmospheric models. Indeed, the role of the Sun is one of the largest unknowns in the climate system [Le Treut et al., 2007]. A number of large‐scale atmospheric dynamic changes are known to occur, on a day‐to‐day timescale, in response to changes in the downward current density of the global atmospheric electric circuit (GEC) [Tinsley, 2008]. One well‐established example of this is the Mansurov effect. This is a response in the surface atmospheric pressure anomaly (with respect to the seasonal average) in the polar regions to changes in the dawn‐dusk component of the interplanetary magnetic field (IMF), By [Mansurov et al., 1974; Tinsley and Heelis, 1993; Burns et al., 2007, 2008; Lam et al., 2013].”
    “A schematic representation of how the proposed global atmospheric electric circuit mechanism produces the correlation between fluctuations in the dawn‐dusk component of the interplanetary magnetic field (IMF), By, and surface atmospheric pressure. The observed IMF By surface pressure correlation, known as the Mansurov effect, is represented by (A), while the proposed physical mechanism acts via paths (B)−(E).”

    The Mansurov effect is one way that minor solar energy components project onto turbulent Earth hydrodynamics via polar vortices – driving Hurst-Kolmogorov stochastic dynamic variability in global systems and climate. Extremes can be very extreme – regimes persistent – transitions abrupt. Climate emerges from the spatio-temporal chaos of the Earth system. As seen in the plethora of Earth system hydrodynamic patterns we call oscillations.

    “It is the goal of pattern formation to understand nonequilibrium systems in which the nonlinearities conspire to generate spatio-temporal structures or pattern.”

    A not general relativity theory of gravity driving climate change – on the other hand – is of course complete nonsense.

  25. Pingback: Weekly Climate And Energy News Roundup #444 – Watts Up With That?

  26. Pingback: Weekly Climate And Energy News Roundup #444 – Climate-

  27. I second that thanks. I have a question for Alan L. or anyone interested.

    The post states, “Atlantic water flowing annually through the Barents Sea continues eastward as the Circumpolar Boundary Current and is the main source of the regional surface water mass. As it goes, it is progressively modified by heat flux to the atmosphere.”

    We know in the Arctic that relatively warmer water rides below considerably cooler less salty water at the surface.

    How effective is this warmer saltier dense water inversion and ice barrier, and cold water just below the ice, at preventing heat loss to the atmosphere relative to open water?

    Open water heat loss is 24 – 7 – 365. Arctic Solar insolation is not 24 – 7 or 365. It is very seasonal, often overcast and is at a very shallow angle with high reflectivity, effectively reducing the effectiveness of said insolation.

    So, on an annual bases is thick sea ice insulating in ocean heat content, and does insulated in relatively warm Atlantic waters, only a bit above the 4C ocean deep water, transport out of the Arctic back to the ocean?

    Your thoughtful consideration appreciated.

    All the Best…

    • I’m not sure why you’re asking me such questions. My point of view is that warm Atlantic waters are known to have entered the Arctic basin in the past on millennial timescales as evidenced here:

      The present era is very reminiscent of past climate cycles so it’s makes sense to assume that a D-O event is starting once again. The YouTube climate scientist Paul Beckwith has come to the same conclusion.

      It isn’t just me.

      • Alan, I am not contradicting anything you have said, just asking, based on your research, what you may think is the net energy difference is between weak arctic insolations seasonal shallow flux into the Arctic, and warm Atlantic water year round influx, and if sea ice is a net insulation to warm arctic water.?


      • David A, it’s not my area of knowledge but off the top of my head it would seem odd to consider thick sea ice as “insulating” warmer water below, based on thermodynamics.

        I would guess that the warm Atlantic current would lose heat to the underside melting of the sea ice much quicker than if it was open water.

      • Thank you Alan, yes, at first I found it counter intuitive.

        My limited research is this…
        “The waters of the Arctic Ocean can be divided into three subsections: Arctic Surface Water (0 to 656 feet); Atlantic Water (650 to 2,950 feet); and Arctic Deep Water (2,950 feet down to the sea floor). Average temperatures of the Arctic Surface Water range from 28.6 °F to 30.2 °F, Except where the warm Atlantic currents flow into the Arctic. the Atlantic Water has an average temperature of 37.4 °F, and Arctic Deep Water has a temperature range of between 30.6 °F to 35.6 °F.”

        So you have up to 600 plus feet of sub 32 degree water, plus sea ice, preventing 37 degree Atlantic water from losing heat to the atmosphere. The Atlantic Water (AW) flows into the Arctic Ocean between 40 and 200 meters deep. At the middle of this flow, the water is up to 5 C warmer than the overlying, colder, relatively fresh water. This Atlantic water deepens as it enters the Arctic. “This drastic change in temperature in the vertical water column is called a “thermocline,” and acts a barrier for upward heat flow. In this case, the thermocline also acts as a “halocline” – a distinct change in saltiness of the water layers. This layering phenomenon is called stratification.” Thus, because the warm AW influx is warmer and saltier, the water remains stratified in the absence of turbulent vertical mixing, and the heat is not released to the surface ocean, sea ice, or atmosphere and climate! The ice is an insulator as well as a wind mixing barrier. I suppose there is always conduction of some heat to the cooler waters above.

        I am curious about the Arctic Arctic Deep Water having a temperature range of between 30.6 °F to 35.6 °F. The 37 plus degree Atlantic water would be denser, unless the bottom water was even saltier.

        The equatorial surface air and water T is very nearly identical. Whereas the arctic water, especially where the major currents bring in warmer waters, is considerably warmer then the atmosphere surface T. This indicates that the non ice polar regions serve as a means of the ocean cooling, it is releasing energy to the atmosphere, and potentially the ice serves as a means of retaining ocean energy.

        Christos says
        “That is why Arctic sea ice has a warming and not a cooling effect on the Global Energy Balance.
        On the other hand it is the open Arctic sea waters that have the cooling effect on the Global Energy Balance”

        Thanks, and that is what I am trying to confirm.
        I am grateful you said “Global Energy Balance”.
        As, while the ocean energy may increase for a time, the much smaller atmospheric energy may diminish, for a time.

        It is curious that in the southern hemisphere summer the earth receives plus 90 watts SqM insolation, yet the atmosphere cools! One well known reason is that the increased snow cover in the Northern hemisphere reflects a great deal of energy. Yet also the southern oceans receive a great deal of additional energy BELOW the ocean surface. And that energy is lost for a time to the atmosphere. What the ocean residence time of disparate S/W insolation is, is not known.
        So a fair question to ask is; despite atmospheric cooling, dies the earth ( land oceans and atmosphere) gain or lose energy during the SH summer?

        So my next question, more cogent to the ocean heat flows and the Arctic is, does the Atlantic water entering the Arctic, re-enter the oceans, and where does it go?

        My guess is that it becomes a part of the very immense bathypelagic zone, 3,200 feet to plus 13,000 feet deep. The temperature in the bathypelagic zone, unlike that of the mesopelagic zone, is constant. The temperature never fluctuates far from a chilling 39°F (4°C)

        However I am not certain, as it may warm a bit on its southern transport.

        Yet a more cogent question is; If the polar ice sheets significantly expanded towards the sub tropics, and warmer waters moved beneath the larger thicker ice sheets (1.) would this warmer water, say take a WAG at 43 degree or 6C, yet still saltier and denser then the colder Arctic surface water, slowly warm the oceans from the bottom up?

        (1.) During the glaciation cold phase of the Ice Ages the equator changes little and the subtropical change varies, but as the atmosphere is dryer, more solar radiation enters the oceans, lost for a time to the atmosphere, like the S.H. summer, but potentially keeping the ocean surface layer as warm or warmer then during an interglacial.)

      • “Thank you Alan, yes, at first I found it counter intuitive.” – David A

        Another thing I find counter intuitive is the idea of ice reflecting *heat* as well as visible light. The amount of energy from reflection of the Sun’s rays in the form of visible light is very low and therefore negligible imo but it has become a foundation block of Milankovitch ice age theory.

        There has been no scientific experiment to show that snow or ice reflects infra red radiation as far as I’m aware. It has simply been assumed it would seem.

        Can you show me that I’m wrong?

      • Alan says, “Can you show me that I am wrong?”
        Regarding infrared radiation not reflecting from ice or snow.
        Nope, I can’t say you are wrong about that.
        However this statement may need additional consideration…
        “The amount of energy from reflection of the Sun’s rays in the form of visible light is very low and therefore negligible imo but it has become a foundation block of Milankovitch ice age theory.”

        According to this visible light is considerable…

        “The three relevant bands, or ranges, along the solar radiation spectrum are ultraviolet, visible (PAR), and infrared. Of the light that reaches Earth’s surface, infrared radiation makes up 49.4% of while visible light provides 42.3% 9. Ultraviolet radiation makes up just over 8% of the total solar radiation.”

        Thus source confirms…

        The visible spectrum, however, accounts for just under half of the Sun’s total energy. Much of the Sun’s energy is made up of ultraviolet (UV) radiation, which has shorter wavelengths (higher energy levels) than visible light and extends off of the purple end of the visible spectrum. An even larger amount of this invisible energy can be found in the longer infrared wavelengths (lower energy levels) of light that extend off the opposite end of the visible spectrum.”

        Also, are not shorter wavelengths more energetic?

        In general I maintain this, ” Only two things can affect the energy content of a system in a radiative balance, either a change in the input, or a change in the residence time of energy within the system.”

        Our system here of course is the land, oceans and atmosphere.

        The corralary to the above statement is that the residence time is dependent on the wavelength of the input, and the materials encountered.

        Thinking in terms of energy residence time may be helpful for some. CO2 for instance, by redirecting some energy back into the system, may be said to increase the residence time of some LW infrared, and, as the input is constant, total energy must increase.

        I found the link on warm Atlantic waters in the past educational.

        All the Best…

      • David A, thank you for the excellent links. The two main relevant paragraphs appear to be:

        Only 56% of the solar radiation that reaches the atmosphere makes it through to earths surface.

        The sun’s radiation must make it through multiple barriers before it reaches Earth’s surface. The first barrier is the atmosphere. About 26% of the sun’s energy is reflected or scattered back into space by clouds and particulates in the atmosphere. Another 18% of solar energy is absorbed in the atmosphere. Ozone absorbs ultraviolet radiation, while carbon dioxide and water vapor can absorb infrared radiation. The remaining 56% of solar radiation is able to reach the surface. However, some of this light is reflected off of snow or other bright ground surfaces, so only 48% is available to be absorbed by land or water. Of the radiation that reaches the surface, approximately half is visible light and half is infrared light. These reflection and absorption percentages can vary due to cloud cover and sun angle. In cloudy weather, up to 70% of solar radiation can be absorbed or scattered by the atmosphere.
        Not all of this light is absorbed by the Earth. Roughly 30 percent of the total solar energy that strikes the Earth is reflected back into space by clouds, atmospheric aerosols, snow, ice, desert sand, rooftops, and even ocean surf.

        It still isn’t clear how much of the Sun’s energy which reaches the snow & ice gets reflected back into *space*, rather than absorbed by the atmosphere. The first link is the most professional and appears to sidestep this crucial figure. The second link appears to misrepresent the first link by implying that 30% of energy reflected off snow & ice makes it back out into space.

        Do you see the subtle distinction that I’m making?

      • Alan, yes, I think. (-;

        So how to quantify the energy of the seasonal albedo flux? Well as a personal experience when I first skied I lost my Goggles for a day and plus, and did not saying anything to my day.
        I went snow blind with tiny blisters on my eyeballs. So, to me, that was extremely painful energy.
        If the additional surface albedo is not significant, how does the plus 90 watts per sq meter Southern Hemisphere Summer insolation lead to a cooler global mean temperature?

        Plus 90 watts per sq meter certainly dwarfed the purported CO2 affect.

      • David A, I have an alternative to Milankovitch insolation theory based on the 100kyr inclination action cycle and new physics tidal forcing.

        For me, “global warming” is a misnomer, just like the The Little Ice Age. I believe the equatorial tropical oceans cool and mid-high latitudes increase in temperature and *precipitation*. Extra snowfall in the polar regions accumulates creating expanding glaciers. This is the simple explanation for the ebb and flow of the ice ages. No GHGs or feedback loops required.

        Your snowblindness sounded nasty. Yes, as discussed, visible light reflection at the surface is still an issue. It’s whether that light makes it to outer space without absorption by the atmosphere which is the quandry.

        Btw the UV sunburn during snowy winters is due to a low Sun in the sky combined with very dry air.

      • Alan says…
        “The Little Ice Age. I believe the equatorial tropical oceans cool and mid-high latitudes increase in temperature and *precipitation*.”

        If you have more on this it would be appreciated. Not certain why the tropical oceans would cool. A cursory assumption would be the evidence of little tropical T change during glaciation, and a cooler atmosphere, holding less humidity and clouds, would potentially result in more solar insolation.

      • “If you have more on this it would be appreciated. Not certain why the tropical oceans would cool.” – David A

        I’m proposing something very counter intuitive: that the ice ages are not driven by insolation but by gravity.

        If tidal forcing increases when the Moon is on the equatorial plane twice a month to create the Spring tides, then a similar mechanism can be applied when the Earth is on Jupiter’s equatorial plane. It will take some time to formulate the mental imagery required but stick with it.

        The Moon currently orbits at 5° to the Earth’s equatorial plane. It therefore crosses this plane twice during it’s monthly orbit. The standard explanation for the Spring tides is that the gravity of the Moon ‘adds up’ with that of the Sun, twice during it’s orbit. The anomaly with this is that during an eclipse, the tide is not fully in. The mainstream counter explanation is that there’s a delay due to friction.

        The supporting scientific evidence is that Earth’s 100kyr orbital inclination cycle is a better fit to the data than eccentricity. Only a viable mechanism is lacking in this paper:

    • The Arctic sea ice has a warming and not a cooling effect on the Global Energy Balance

      It is true that the sea ice has a higher reflecting ability. It happens because ice and snow have higher albedo.

      But at very high latitudes, where the sea ice covers the ocean there is a very poor insolation absorption.
      Thus the sea ice’s higher reflecting ability doesn’t cool significantly the Earth’s surface.

      On the other hand there is a physical phenomenon which has a strong influence in the cooling of Earth’s surface. This phenomenon is the differences in emissivity.

      The open sea waters have emissivity ε = 0,95.
      The ice has emissivity ε = 0,97.

      On the other hand, the snow has a much lower emissivity ε = 0,8.
      And the sea ice is a snow covered sea ice with emissivity ε = 0,8.

      Also we should have under consideration the physical phenomenon of the sea waters freezing-melting behavior.
      Sea waters freeze at – 2,3 oC.
      Sea ice melts at 0 oC.

      The difference between the melting and the freezing temperatures creates a seasonal time delay in covering the arctic waters with ice sheets.

      When formatting the sea ice gets thicker from the colder water’s side.
      When melting the sea ice gets thinner from the warmer atmosphere’s side.

      This time delay enhances the arctic waters IR emissivity and heat losses towards the space because of the open waters’ higher emissivity ε = 0,95,
      compared with the snow covered ice ε = 0,8.

      Needs to be mentioned that Earth’s surface emits IR radiation 24/7 all year around.
      And the Arctic region insolation absorption is very poor even in the summer.

      That is why Arctic sea ice has a warming and not a cooling effect on the Global Energy Balance.
      On the other hand it is the open Arctic sea waters that have the cooling effect on the Global Energy Balance.

      Feedback refers to the modification of a process by changes resulting from the process itself. Positive feedbacks accelerate the process, while negative feedbacks slow it down.
      The Arctic sea ice has a warming and not a cooling effect on the Global Energy Balance. It is a negative feedback.

      The melting Arctic sea ice, by opening the waters, slows down the Global Warming trend. This process appears to be a negative feedback.

      The LIA was a long negative feedback response period. The general trend was then and is now a continuous orbital forced global warming.

      • Christos, I am gainfully employed for now, but will have some more questions for you when I have some time this evening. So please check back.

      • David, I will be glad to answer your questions. I will check back tomorrow, because it is too late in Greece, where I am.

      • Christos, please see my conjecture question just above here…

        or just scroll up a bit…
        Thanks in advance, all the Best…
        I am in Southern California by the way.

      • Thank you David for asking.
        You said:
        “The amount of energy from reflection of the Sun’s rays in the form of visible light is very low and therefore negligible imo but it has become a foundation block of Milankovitch ice age theory.”

        I would like to make a statement about the Milankovitch ice age theory:
        Milankovitch cycle should be read REVERSED.

        The ORIGINAL Milankovitch Cycle
        On the first graph below is the Original Milankovitch Cycle.

        According to Milankovitch Ice Ages are generally triggered by minima in high-latitude Northern Hemisphere summer insolation, enabling winter snowfall to persist through the year and therefore accumulate to build Northern Hemisphere glacial ice sheets. Similarly, times with especially intense high-latitude Northern Hemisphere summer insolation, determined by orbital changes, are thought to trigger rapid deglaciations, associated climate change and sea level rise.

        But Earth cannot accumulate heat on the continents’ land masses. Earth instead accumulates heat in the oceanic waters.
        It is the Original Milankovitch cycle

        The REVERSED Milankovitch Cycle
        Milankovitch’s main idea was that the glacial periods are ruled by planet’s movements forcing.
        And this is the Reversed Milankovitch cycle

        On the second graph it is the Reversed Milankovitch cycle. The minimums in the reversed Milankovitch cycle are the maximums in the original. These two cycles, the original Milankovitch cycle and the reversed differ in time only by a half of a year. According to the REVERSED Milankovitch cycle there are long and very deep glacial periods and small and very short interglacial. The reversed cycle complies with the paleo geological findings. As we can see in the reversed Milankovitch cycle, we are getting now to the end of a long and a slow warming period. What we are witnessing as a Global Climate Change are the culmination moments at the end of that warming period.

  28. Rather than standing on the shoulders of giants – whom they vilify as fools and deceivers – contrarians dig holes for themselves.

  29. There is a Scandinavian climate, the Central Europe climate, the Mediterranean climate, the North African climate etc.… Climate is the solar angular incidence dependent phenomenon.
    Thus you cannot have a Mediterranean climate in Baltic, but you may observe a Mediterranean weather in Baltic – yes it is possible, but it is not climate, it is just a temporarily warmer weather

    Climate is about the temperature of the sea surface and the temperature of the ground.
    Weather is about what happens in atmosphere. Weather is about air temperature, about wind velocity, about cloudiness, rain and snow.

    Earth’s planetary climate is an average of the local climates – that’s all.

  30. Glacials originate as snow survives in periods of low NH summer insolation – and with reduced ocean and atmosphere driven thermohaline circulation. There are both albedo and biokinetic CO2 positive feedbacks.
    “At the height of the last ice age (glacial maximum) global sea levels were a remarkable 120 metres lower than today (Clark & Mix [2002], Peltier [2002]) . For comparison, at most there is around 65-70 metres worth of global sea level rise volume currently locked up in the ice sheets of Greenland and Antarctica, so the ancient ice sheets were much larger than the land-based ice which currently remains. The vast Laurentide ice sheet which once sat over modern-day Canada, was at least 3 kilometres thick at its highest point (Dyke [2002], Peltier [2004]), and contained around 80 metres of global sea level volume, which gives some idea of how enormous it was.”

    The fundamentals are relatively simple. But all of the known, relevant physical processes need to be incorporated into any reasonable conceptual model. In my view it is pointless to posit causal unknowns. Snow and ice for instance absorb thermal energy and melt or turn to vapor. There are huge amounts of latent energy in oceans and atmosphere. The latent heat is released on freezing or on condensation and this energy ultimately makes its way out of the Earth system. It should be remembered as well that with summer sea ice the ice cover is far from unbroken. The more ice lost the more heat is lost from oceans to atmosphere to space.

    The fundamental relationship is that the change in heat and work in the system is equal to energy in less energy out. Quantifying these must rely on observation and not hand waving however logical it appears to proponents of this or that.

  31. Glacials originate as snow survives in periods of low SH summer insolation – and with reduced ocean and atmosphere driven thermohaline circulation.

    The difference is, instead of “low NH summer insolation” which is in accordance to Original Milankovitch cycle concept, the correct “low SH summer insolation” which is according to the REVERSED Milankovitch cycle.

  32. Thank you Robert, good question.
    Fragment of the Reversed Milankovitch Cycle

    It is an over 21 thousands years very slow orbital forced climate cycle.
    It happens, we are now at the upper point of the cycle. It happens the SH summer to coincide with the Earth’s Perihelion.
    Thus, in SH summers, Southern Oceans are both, CLOSER to the sun and TILTED towards the sun.
    Oceans accumulate solar energy and slowly distribute it around the entire Globe. We are now in a positive +ΔQ energy in less energy out budget.

    Slowly it is going to change to the opposite, to the negative -ΔQ energy in less energy out budget. Slowly there will be less energy accumulated in the Earth’s system.

    At the opposite position of the over 22.000 years cycle, in 11.000 years Earth’s Perihelion will occur near to the North Hemisphere’s summer.
    It will result to much more intensively solar irradiated summers, and much colder winters in NH.
    On the Southern Hemisphere the oceans will be TILTED towards the sun, but they will be FURTHER from the sun, than they are now – consequently there would be much less solar energy accumulated available.
    It is a very slow process. Now the SH annually accumulates much more solar energy, than it would accumulate in 11.000 years.

    So there will be less energy available in the Earth’s system. Thus ice sheets gradually and very slowly will grow higher and higher, and nothing could prevent them from that…

  33. Antarctica is a natural control for the impact of CO2 on temperatures. There is little to no water vapor, minimal pollution, and CO2 equal to the rest of the world. What do you find? You find that Antarctica, and other desserts both hot and cold, show no warming with an increase in CO2. Here are the stations.
    Amundsen Scott (90.0S, 0.0000E) ID:AYW00090001
    Halley (75.45S, 26.217W) ID:AYM00089022
    Sanae Saf Base (70.3S, 2.35W) ID:AYM00089001
    Mawson (67.6S, 62.8670E) ID:AYM00089564
    Davis (68.583S, 77.9500E) ID:AYM00089571
    Mirnyj (66.55S, 93.0170E) ID:AYM00089592
    Casey (66.283S, 110.5170E) ID:AYM00089611
    Dumont D’Urville (66.667S, 140.0170E) ID:AYM00089642
    Isla De Pascua East (67.17S, 109.43W) ID:XXXLT848602
    Rothera (67.567S, 68.117W) ID:AYM00089062
    Vernadsky (65.25S, 64.267W) ID:AYM00089063

  34. Undermatrix What a strange study. We’d like scientists to check it…