BIG GREENLAND UPDATE

That the polar ice caps will melt and cause a vast rise in the sea-level is the core of the global warming scare. Unfortunately, the Southern icecap is being un-co-operative. Central Antractica is, if anything, cooling. That leaves the Northern icecap. Some parts of the Arctic are in fact warming but most of the Northern icecap floats on the sea and basic physics tells you that the melting of floating ice does exactly nothing to the water level of the body in which it floats. So the Greenland icecap is the big question-mark. Most of the land-based Northern icecap is located there. If it were to melt, that might have some effect. Initial evidence, however, indicated that Greenland is being pesky too. Contrary to what the global warmers want, Greenland seems to be COOLING. In recent years, however, much new evidence and commentary has become available on the question. Some of it is reproduced below. The results are cold comfort (to coin a phrase) for the global warmers:




Recent Ice-Sheet Growth in the Interior of Greenland

By: Ola M. Johannessen, Kirill Khvorostovsky 2, Martin W. Miles, Leonid P. Bobylev

A continuous data set of Greenland Ice Sheet altimeter height from ERS-1 and ERS-2 satellites, 1992 to 2003, has been analyzed. An increase of 6.4 ñ 0.2 centimeters per year is found in the vast interior areas above 1500 meters, in contrast to previous reports of high-elevation balance. Below 1500 meters, the elevation-change rate is -2.0 ñ 0.9 cm/year, in qualitative agreement with reported thinning in the ice-sheet margins. The spatially averaged increase is 5.4 ñ 0.2 cm/year, or ~60 cm over 11 years, or ~54 cm when corrected for isostatic uplift. Winter elevation changes are shown to be linked to the North Atlantic Oscillation.

(The above abstract is from Science, 20 October 2005. Below is a fuller account of the work:)

Greenland's ice cap has thickened slightly in recent years despite wide predictions of a thaw triggered by global warming

Recent growth in the interior regions of the Greenland Ice Sheet is reported by a Norwegian-led team of climate scientists. The growth is estimated to be about 6 cm per year during the study period, 1992-2003. They derive and analyse the longest continuous dataset of satellite altimeter observations of Greenland Ice Sheet elevations by combining tens of millions of data points from European Space Agency (ESA) satellites, called ERS-1 and ERS-2, and NASA. This allowed the scientists to determine the spatial patterns of surface elevation variations and changes over an 11-year period between 1992 and 2003.

The motivation for the study of the Greenland Ice Sheet is related to global climate change. First, complete melting of the ice sheet would raise the global sea level up to 7 meters. This process, expected to occur on a millennial time scale, should begin upon crossing the critical threshold for surface air temperature increase (~3§C) for Greenland, which is predicted to happen before the end of this century. Second, increased Greenland Ice Sheet melt and freshwater input into the northern North Atlantic Ocean is theorized to weaken the Gulf Stream at high latitudes and possibly even disrupt the global thermohaline circulation on a relatively rapid, multi-decadal time scale. If this were to happen, it would severely impact the climate of northern Europe and even on a global scale.

Efforts to measure changes in the Greenland Ice Sheet from field observations, aircraft and satellite remote sensing - such as altimeters that measure surface height - have improved our knowledge over the past decade. However, there is still no consensus assessment of the overall mass balance of the ice sheet. There is however evidence of melting and thinning in the coastal marginal areas in recent years, as well as indications that large Greenland outlet glaciers can surge, possibly in response to climate.

However, much less known are changes that may occur in the vast elevated interior area of the ice sheet (Images 1 and 2). Previous studies by American scientists had reported a high-elevation ice-sheet balance. However, those assessments were based on a limited number of tracks of aerial altimetry, unevenly sampled in space and time, as well as short records from satellites.

Source





ERS altimeter survey shows growth of Greenland Ice Sheet interior

Researchers have utilised more than a decade's worth of data from radar altimeters on ESA's ERS satellites to produce the most detailed picture yet of thickness changes in the Greenland Ice Sheet.

A Norwegian-led team used the ERS data to measure elevation changes in the Greenland Ice Sheet from 1992 to 2003, finding recent growth in the interior sections estimated at around six centimetres per year during the study period. The research is due to be published by Science Magazine in November, having been published in the online Science Express on 20 October.

ERS radar altimeters work by sending 1800 separate radar pulses down to Earth per second then recording how long their echoes take to bounce back 800 kilometres to the satellite platform. The sensor times its pulses' journey down to under a nanosecond to calculate the distance to the planet below to a maximum accuracy of two centimetres.

ESA has had at least one working radar altimeter in polar orbit since July 1991, when ERS-1 was launched. ESA's first Earth Observation spacecraft was joined by ERS-2 in April 1995, then the ten-instrument Envisat satellite in March 2002.

The result is a scientifically valuable long-term dataset covering Earth's oceans and land as well as ice fields - which can be used to reduce uncertainty about whether land ice sheets are growing or shrinking as concern grows about the effects of global warming.

The ice sheet covering Earth's largest island of Greenland has an area of 1 833 900 square kilometres and an average thickness of 2.3 kilometres. It is the second largest concentration of frozen freshwater on Earth and if it were to melt completely global sea level would increase by up to seven metres.

The influx of freshwater into the North Atlantic from any increase in melting from the Greenland Ice Sheet could also weaken the Gulf Stream, potentially seriously impacting the climate of northern Europe and the wider world.

Efforts to measure changes in the Greenland Ice Sheet using field observations, aircraft and satellites have improved scientific knowledge during the last decade, but there is still no consensus assessment of the ice sheet's overall mass balance. There is however evidence of melting and thinning in the coastal marginal areas in recent years, as well as indications that large Greenland outlet glaciers can surge, possibly in response to climate variations.

Much less known are changes occurring in the vast elevated interior area of the ice sheet. Therefore an international team of scientists - from Norway's Nansen Environmental and Remote Sensing Center (NERSC), Mohn-Sverdrup Center for Global Ocean Studies and Operational Oceanography and the Bjerknes Centre for Climate Research, Russia's Nansen International Environmental and Remote Sensing Center and the United States' Environmental Systems Analysis Research Center - were compelled to derive and analyse the longest continuous dataset of satellite altimeter observations of Greenland Ice Sheet elevations.

By combining tens of millions of data points from ERS-1 and ERS-2, the team determined spatial patterns of surface elevation variations and changes over an 11-year period.

The result is a mixed picture, with a net increase of 6.4 centimetres per year in the interior area above 1500 metres elevation. Below that altitude, the elevation-change rate is minus 2.0 cm per year, broadly matching reported thinning in the ice-sheet margins. The trend below 1500 metres however does not include the steeply-sloping marginal areas where current altimeter data are unusable.

The spatially averaged increase is 5.4 cm per year over the study area, when corrected for post-Ice Age uplift of the bedrock beneath the ice sheet. These results are remarkable because they are in contrast to previous scientific findings of balance in Greenland's high-elevation ice.

The team, led by Professor Ola M. Johannessen of NERSC, ascribe this interior growth of the Greenland Ice Sheet to increased snowfall linked to variability in regional atmospheric circulation known as the North Atlantic Oscillation (NAO). First discovered in the 1920s, the NAO acts in a similar way to the El Ni¤o phenomenon in the Pacific, contributing to climate fluctuations across the North Atlantic and Europe.

Comparing their data to an index of the NAO, the researchers established a direct relationship between Greenland Ice Sheet elevation change and strong positive and negative phases of the NAO during winter, which largely control temperature and precipitation patterns over Greenland.

Professor Johannessen commented: "This strong negative correlation between winter elevation changes and the NAO index, suggests an underappreciated role of the winter season and the NAO for elevation changes - a wildcard in Greenland Ice Sheet mass balance scenarios under global warming."

He cautioned that the recent growth found by the radar altimetry survey does not necessarily reflect a long-term or future trend. With natural variability in the high-latitude climate cycle that includes the NAO being very large, even an 11-year long dataset remains short.

"There is clearly a need for continued monitoring using new satellite altimeters and other observations, together with numerical models to calculate the Greenland Ice Sheet mass budget," Johannessen added.

Modelling studies of the Greenland Ice Sheet mass balance under greenhouse global warming have shown that temperature increases up to about 3§C lead to positive mass balance changes at high elevations - due to snow accumulation - and negative at low elevations - due to snow melt exceeding accumulation.

Such models agree with the new observational results. However after that threshold is reached, potentially within the next hundred years, losses from melting would exceed accumulation from increases in snowfall - then the meltdown of the Greenland Ice Sheet would be on.

A paper published in Science in June this year detailed the results of a similar analysis of the Antarctic Ice Sheet based on ERS radar altimeter data, carried out by a team led by Professor Curt Davis of the University of Missouri-Columbia.

The results showed thickening in East Antarctica on the order of 1.8 cm per year, but thinning across a substantial part of West Antarctica. Data were unavailable for much of the Antarctic Peninsula, subject to recent ice sheet thinning due to regional climate warming, again because of limitations in current radar altimeter performance.

ESA's CryoSat mission, lost during launch on 8 October, carried the world's first radar altimeter purpose-built for use over both land and sea ice. In the context of land ice sheets, CryoSat would have been capable of acquiring data over steeply-sloping ice margins which remain invisible to current radar altimeters - these being the very regions where the greatest loss is taking place.

Efforts are currently underway to investigate the possibility of building and flying a CryoSat-2, with a decision to be taken by the end of the year. In the meantime, the valuable climatological record of ice sheet change established by ERS and Envisat will continue to be extended.

Source





Global Warming and the Greenland Ice Sheet

Abstract

The Greenland coastal temperatures have followed the early 20th century global warming trend. Since 1940, however, the Greenland coastal stations data have undergone predominantly a cooling trend. At the summit of the Greenland ice sheet the summer average temperature has decreased at the rate of 2.2 øC per decade since the beginning of the measurements in 1987. This suggests that the Greenland ice sheet and coastal regions are not following the current global warming trend. A considerable and rapid warming over all of coastal Greenland occurred in the 1920s when the average annual surface air temperature rose between 2 and 4 øC in less than ten years (at some stations the increase in winter temperature was as high as 6 øC). This rapid warming, at a time when the change in anthropogenic production of greenhouse gases was well below the current level, suggests a high natural variability in the regional climate. High anticorrelations (r = -0.84 to -0.93) between the NAO (North Atlantic Oscillation) index and Greenland temperature time series suggest a physical connection between these processes. Therefore, the future changes in the NAO and Northern Annular Mode may be of critical consequence to the future temperature forcing of the Greenland ice sheet melt rates.

(From Chylek, P. Box J.E., Lesins G. Climatic Change, Volume 63, Numbers 1-2, March 2004)





Greenland and Global Warming

Recent popular media coverage of climate change issues has presented a scary scenario in which human-induced global warming will give rise to a new ice age. Indeed, this is the scenario sketched out in the climate disaster movie The Day After Tomorrow. It sounds counterintuitive, so lets explain the science behind the scare scenario, such as it is.

Popular media of climate change has warned that increased man-made CO2 emissions will raise temperatures and thus melt the Greenland ice sheet, filling the Atlantic Ocean with excess fresh water. This will have the unintended effect of shutting down the North Atlantic Thermohaline Circulation or the North Atlantic oceanic heat conveyor belt. This would mean the possible discontinuation of the flow of heat from the tropics to the north pole through the North Atlantic Gulf Stream. The New York Timess Andrew Revkin emphasized in a June 8 article that a big outflow of water from Greenland could take the system to a tipping point.

Will It Happen?

But such a threat, as predicted from current computer climate models, is most likely an exaggerated hype. In a letter for the April 8 issue of the journal Nature, Professor Carl Wunsch of MIT explained that:

Real questions exist about conceivable changes in the ocean circulation and its climate consequences. However, such discussions are not helped by hyperbole and alarmism. The occurrence of a climate state without the Gulf Stream any time soon -- within tens of millions of years -- has a probability of little more than zero.

European readers should be reassured that the Gulf Streams existence is a consequence of the large-scale wind system over the North Atlantic Ocean, and of the nature of fluid motions on a rotating planet. The only way to produce an ocean circulation without a Gulf Stream is either to turn off the wind system, or to stop the Earth's rotation, or both.

OK, so a warming planet might not shut down the Gulf Stream. But what of the concern that a warming planet will result in a melting of the Greenland ice sheet? After all, a mere 15-pages after Professor Wunschs caution in the April 8 issue of Nature, a team of European climate modelers on page 616 offers new concerns of their own, claiming the Greenland ice sheet could be wiped out:

The Greenland ice-sheet would melt faster in a warmer climate and is likely to be eliminated -- except for residual glaciers in the mountains -- if the annual average temperature in Greenland increases by more than about 3C. This could raise the global average sea-level by 7 metres over a period of 1,000 years or more. We show here that concentrations of greenhouse gases will probably have reached levels before the year 2100 that are sufficient to raise the temperature past this warming threshold. Without the ice-sheet, the climate of Greenland would be much warmer because the land surface would be a lower altitude and reflect less sunlight. This conclusion can be drawn without detailed modeling. Even if atmospheric composition and the global climate were to return to pre-industrial conditions, the ice-sheet might not be regenerated, which implies that sea-level rise could be irreversible.

Irreversible Developments?

These European authors gained further confidence in their conclusion from a separate climate modeling experiment published earlier this year (January 2004) in the Journal of Climate. Instead of showing us that the Greenland ice-sheet will melt away completely in their climate models, these authors first artificially removed all the ice in Greenland and asked if their climate models would regenerate the Greenland ice sheet when they set their model atmosphere at the pre-industrial level of greenhouse gas concentrations. They failed to have any net accumulation of snow after crunching their computer climate model for some 70 years.

Their conclusion is that the removal of the Greenland ice sheet due to prolonged climatic warming would be irreversible. Overall, the modified Greenland climate is not very different from that of some forested areas such as in eastern Siberia. But these authors also admitted that their modeling result does depend on the sensitivity of the GCM to orography and on the assumed heat transport across the stably stratified boundary layer [the layer of turbulent air between the surface and free troposphere with a few hundred meters in thickness] over Greenland in winter and in spring.

Extremely Unlikely

So what can one expect for Greenland under the UN IPCCs global warming scenarios (which predict a disproportionately larger warming over Greenland)? Will a fully reforested Greenland with a marshy environment emerge once annual average CO2 warming at Greenland gets above 2.7C? Or will we find the opposite extreme of an icy-cold Greenland with an ever expanding and larger ice-sheet if the North Atlantic Thermohaline Circulation is shut down?

While both extremes have been offered up by climate experts over the last few months through the popular media, I suggest that neither extreme will prevail because reality is simply far too complex to even consider these modeled extremes as legitimate climate predictions. The available climatic data for Greenland and over the North Atlantic simply do not give us confidence in the currently available modeled scenarios of Greenland.

Lets start with the raw evidence for our current inability to model climatic change with any degree of confidence. Here one need not go too far to find that region by region modeling of both the complete melting and regeneration of the Greenland ice sheet is indeed largely a matter of faith rather than any actual science.

In the aforementioned April 8 issue of Nature, on page 593, one learned from a top climate modeler that If you dont believe in the value of global climate model then theres no point in down scaling them [to get regional pattern of change as in Greenland.]

Figure 2 shows one reason I do not believe in the value of global climate model. This chart shows the extreme sensitivity of surface winter temperature change on local and regional scales to how a model represents the physics of the boundary layer. This boundary layer is critical to how both heat and moisture are exchanged between the surface and the free atmosphere, especially during winters and springs over Greenland as noted earlier by those European modelers that successfully produced a permanently bare Greenland. But the authors of Figure 2 clearly show that with only a slight change or tuning of how heat is being exchanged or mixed, the model differences of the winter surface temperature can be as large as 2 to 10C -- some of these intra-model temperature differences are certainly as large as those being claimed for CO2-global warming scenarios studied in Figure 1.

Next, the above model experiments for Greenland and large temperature warming in Figure 1 had clearly failed to recognize several contradictory facts from the available temperature data in Greenland. Petr Chylek of the Los Alamos National Laboratory and colleagues, in their paper published in the journal Climatic Change March 2004, found that:

The Greenland surface air temperature trends over the past 50 years do not show persistent warming, in contrast to global average surface air temperatures. The Greenland coastal stations temperature trends over the second half of the past century generally exhibit a cooling tendency with superimposed decadal scale oscillations related to the NAO [i.e., the dynamic of North Atlantic Oscillation atmospheric circulation]. At the Greenland ice sheet summit, the temperature record shows a decrease in the summer average temperature at the rate of about 2.2C/decade, suggesting that the Greenland ice sheet at high elevations does not follow global warming trend either. A significant and rapid temperature increase was observed at all Greenland stations between 1920 and 1930. The average annual temperature rose between 2 and 4C in less than ten years. Since the change in anthropogenic production of greenhouse gases at that time was considerably lower than today, this rapid temperature increase suggests a large natural variability of the regional climate.

Whats more, in a study of sea ice conditions and its historical changes around the Fram Strait (i.e., located northeast of Greenland) and ice flows around the coast of southwestern Greenland published last year in the Journal of Climate, Torben Schmith and Carsten Hansen of the Danish Meteorological Institute found that the annual export of ice through the Fram Strait is strongly correlated with the see-saw pattern of winter atmospheric circulation in the North Atlantic during the 1980-1990 interval called the North Atlantic Oscillation. Simultaneously, they also found a similar relationship suggesting the importance of atmospheric wind flow on the export of sea ice through the Fram Strait for earlier intervals around 1930-1950 and 1840-1860. This fact allows Schmith and Hansen to conclude that this casts doubt on the hypothesis of enhanced greenhouse effect being the cause for the recent increase in correlation coefficient [during 1980-1990]. In addition, this sea ice study independently confirms the conclusion by Chlek and colleagues that large natural variability of climatic and environmental variables around Greenland is the norm rather than the exception to be expected strictly from man-made greenhouse gases.

Finally, it has long been known that the Greenland ice sheet probably originated some 2.4 million years ago. It is further deduced from geological records that the Greenland ice sheet is most likely the only Northern Hemisphere ice sheet to have survived the last Interglacial warm period around 130 to 115 thousand years ago (also roughly known as the Eemian warm period through terrestrial records from Europe). It must be emphasized that observed climatic and environmental changes during the last interglacial around the North Atlantic region are indeed dramatic. For example, tall mixed hardwood forests with a closed canopy covered much of Europe during the peak warm period and after about 115 thousand years ago, open vegetation replaced the mixed forests in northwestern Europe.

Professor Svend Funder[1] of the Geological Museum at the University of Copenhagen and his colleagues described the climatic and environmental conditions around Central and East Greenland [see the two marked locations in Figure 2] during the Eemian warm period as follows[2]:

During the [Eemian warm period], Jameson Land had a different appearance from the present, and also from what it had during the Holocene climatic optimum [i.e., about 5 to 9 thousand years ago]. At present, the optimal type of vegetation is dwarf shrub heath, during the [Eemian warm period] there were copses of birch and alder on sheltered sites, and the heaths contained several plant, moss, and insect species which today only live in the warmer west Greenland. Bennike and Bocher (1994) concluded that summer temperatures were 5 [C] higher than at present, and ca. 3-4 higher than during the Holocene climatic optimum. Also the marine faunas contain a number of subarctic species which are now absent from the East Greenland coast. These include Mytilus edulis and Chlamys islandica [i.e., species of mollusks with shells consisting of twin valves including mussels and clams], which lived in the area for some millennia during the Holocene climatic optimum, while Lacuna divaricata, Buccinum undatum, and Boreotrophon truncatus [i.e., species of gastropods or mollusks with single piece of straight or spiral shells like snails, limpets or with no shells like slugs, etc.] are restricted to West Greenland, and have not been recorded before in East Greenland. Finally, the gastropod Solariella varicosa has not been found earlier in Greenland. These subarctic species require warm Atlantic water to maintain their reproduction, and show that more Atlantic water was advected into the Nordic Sea and the Arctic in general than during the Holocene. Some oceanic species which are now restricted to the open coasts, also extended into the fjord system and show that water exchange between the ocean and the fjord system was more vigorous in agreement with marine geological results from the continental shelf. In summary, summer temperatures were already ca. 5 higher than at present and the oceanic circulation more vigorous with a large influx of Atlantic water than in the Holocene, at the time when the coast of Jameson Land was deglaciated. These conditions lasted longer than 3500 years.

So it is clear that the Greenland ice sheet did not simply melt away despite rather extreme climatic conditions and swings during the last interglacial. In addition, it is equally important to note that during the persistent warmth of the Eemian Interglacial, there were no signs of a weakening or a total shut down of the North Atlantic thermohaline circulation in climatic records around the North Atlantic-Greenland region despite the distinct possibility for excessive freshening of the North Atlantic ocean from enhanced rainfall and melting of Greenlands coastal ice.

Furthermore it may also be possible to rule out the computer scenario that suggests that the bare Greenland could not regenerate and re-support its ice sheet simply because a net accumulation of local snow was not possible in their model run after 70 years. Today, the ice thickness is over 3000 meters at Summit, Central Greenland (see the location marked in Figure 2), the site of the Greenland Ice Core Project (GRIP). From the work of Professor Roland Souchez[3] at the Universit de Bruxelles, it is known that the gas contents of the basal silty ice (at depths between 3023 and 3029 meters) from the GRIP core at Summit, Greenland have enormously high levels of CO2 from about 30,000 ppm to 130,000 ppm and CH4 from about 1,000 to 6,000 ppm, while the 1980s-1990s atmospheric levels of CO2 and CH4 are about 360-370 ppm and 1.5-1.85 ppm, respectively.

Professor Souchez reasoned that the most probable scenario that could explain this observation[4] is that:

such [basal] ice was developed probably within a peat deposit in a permafrost environment [when Central Greenland was bare without the giant ice sheet]. This local ice was subsequently intimately mixed with glacier ice from an advancing ice sheet progressing on this site. This is in agreement with the highland origin and windward growth hypothesis for ice sheet development, not for an in situ or regional growth from snowbanks. The basal ice from the GRIP core possibly dates back to the original buildup of the Greenland Ice Sheet 2.4 million years ago. [Also] as suggested by a recent comparison of the isotopic profiles of GISP 2 [Greenland Ice Core Project 2] and of the GRIP cores, the ice sheet was developed in the Summit region during the Eemian [i.e., the last interglacials] It can be [further] assumed that the Greenland Ice Sheet was developed during the interglacials preceding the Eemian since the climate during these periods was less warm than that of the Eemian. The basal ice thus possibly represents the original build-up of the Greenland Ice Sheet.

In other words, the Greenland Ice Sheet has a long history of being stable for the past 2.4 million years enduring all extremes of warm and dry conditions most likely dwarfing even what is being emphasized by the UN IPCC CO2 global warming scenarios. Furthermore, it is clear that the Greenland Ice Sheet was not built by local deposition and accumulation of snow year after year as simplistically evaluated in the current computer models. As Souchez concluded:

The preservation at the base of GRIP core of ice of local origin, formed most probably within a peat deposit in a permafrost environment, mixed with glacier ice from an ice sheet, is in itself a strong argument against in situ growth of the Greenland Ice Sheet.

(Above article by Dr Willie Soon, 10 June, 2004. Figures referred to are no longer online)

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Many people would like to be kind to others so Leftists exploit that with their nonsense about equality. Most people want a clean, green environment so Greenies exploit that by inventing all sorts of far-fetched threats to the environment. But for both, the real motive is to promote themselves as wiser and better than everyone else, truth regardless.

Global warming has taken the place of Communism as an absurdity that "liberals" will defend to the death regardless of the evidence showing its folly. Evidence never has mattered to real Leftists

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