Saturday, March 18, 2006

Hot Air Hysteria: Dubious base-level for CO2 comparisons at work again

Atmospheric levels of carbon dioxide are at record highs according to a new report from the UN's World Meteorological Organization. The implication is that manmade greenhouse gas emissions and therefore, global warming, are spiraling out of control. But the report is misleading to the extent it claims that the atmospheric carbon dioxide (CO2) level - reported by the WMO to be 377 parts per million (ppm) in 2004 - is 35 percent higher now than during pre-industrial times when the CO2 level allegedly was around 280 ppm.

While there's no dispute concerning the current CO2 level, there is plenty of room to dispute the WMO's 280 ppm-estimate for pre-industrial atmospheric CO2, according to March 2004 testimony before the U.S. Senate by Dr. Zbigniew Jaworowski, a senior Polish scientist who has spent 40 years studying glaciers in order to reconstruct the history of human impact on the global atmosphere.

Atmospheric CO2 can be measured directly by air sampling or estimated indirectly by, for example, studying air trapped in ice cores drilled from glaciers. Direct measurements of atmospheric CO2 taken by scientists during the 19th century - beginning around 1810 - ranged from about 250 ppm to 550 ppm, with an average value of 335 ppm, according to Dr. Jaworowski. Global warming alarmists, however, prefer to estimate pre-industrial CO2 indirectly by means of ice cores, from which they derive the much lower pre-industrial revolution estimate of 280 ppm. The lower estimate makes industrial-era greenhouse gas emissions appear to be dramatically higher.

But Dr. Jaworowski says that the ice core-based CO2 estimates are unreliable. First, ice core-based CO2 estimates vary even more than the 19th century direct measurements, generally ranging from 160 ppm to about 700 ppm with some readings as high as 2,450 ppm. But because the higher estimates are politically incorrect - that is, they don't support the notion of manmade global warming - Dr. Jaworowski says they haven't been mentioned in the published scientific literature since the mid-1980s when global warming fever began to spread.

The official "rationale" for ignoring the higher ice core readings is that they supposedly have been "contaminated" by the contemporary atmosphere -- but it's an excuse that actually undermines the validity of all ice cored-based measurements. Ice core data do get contaminated, according to Dr. Jaworowski, but in the opposite direction.

In order for ice core data to be considered reliable, the ice matrix must be a closed system - that is, once air is trapped in ice it should remain unchanged. But Dr. Jaworowski says that glaciers aren't closed systems. Liquid water is present even in the coldest Antarctic ice (-73 degrees Centigrade). "More than 20 physico-chemical processes, mostly related to the presence of liquid water, contribute to the alteration of the original chemical composition of the air inclusion in polar ice," Dr. Jaworowski told Senators.

The act of drilling for ice core samples further alters the composition of the trapped air. As deep ice is compressed, trapped air bubbles turn into tiny crystals. Drilling decompresses ice cores - causing cracks in the ice and decomposition of the crystals into gases which differentially escape at varying pressures and depths - leading to a net depletion of CO2 in the air trapped in the ice cores, according to Dr. Jaworowski. "This is why the records of carbon dioxide. in deep polar ice show values lower than in the contemporary atmosphere, even for epochs when the global surface temperature was higher than now," Dr. Jaworowski testified.

If pre-industrial CO2 levels are in fact closer to the directly measured 19th century average of 335 ppm versus the questionably estimated 280 ppm, then human activity would be correlated with a much smaller increase in atmospheric CO2 levels - which only adds to the confusion over global warming.

Mean global temperature appears to have warmed by about one degree Fahrenheit during the 20th Century. About half that warming occurred prior to 1940, while most of the century's manmade greenhouse gas emissions occurred after 1940. The global cooling that occurred from 1940 to 1970 - which led some worriers to sound alarms during the mid-1970s about a looming ice age - actually occurred simultaneously with increasing manmade greenhouse gas emissions.

There really are only two certainties in the debate over climate change. First, we really don't have a sufficient understanding of climatic processes to predict with reasonable certainty the impact of greenhouse gas emissions on climate.

But we do know that mandatory caps on greenhouse gas emissions - like those required in Europe by the Kyoto Protocol and currently advocated in the U.S. by Sens. Pete Domenici, R-N.M., and Jeff Bingman, D-N.M., - will harm the economy by making energy more expensive and less available. European nations are already choosing to forgo global warming alarmism and compliance with Kyoto in favor of economic survival and growth. Let's hope that message gets through the global warming ice core in which Sens. Domenici and Bingaman seem to be trapped



The United States and Russia yesterday united to throw their weight behind nuclear energy, with America calling for a "very substantial rebirth" of the industry. The endorsement of atomic power by the two former Cold War foes will provide a significant boost to the ambitions of American, French and Russian nuclear industries.

However, their stand, unveiled at a meeting of G8 energy ministers in Moscow, was greeted with dismay by environmentalists and signalled a shift from the line endorsed at last year's summit in Gleneagles, which focused on renewable energy.

Addressing the meeting, Vladimir Putin, the Russian President, called for unity among G8 member states in tackling energy supply problems and said: "Atomic energy alternatives must be accessible to other countries, including developing countries."

Samuel Bodman, the US Energy Secretary, said after the meeting: "We are hopeful of a very substantial rebirth of the global nuclear industry."

A joint statement issued by all the energy ministers hinted at the continuing division among G8 member states over nuclear energy, which is endorsed strongly by France, Russia and the US but remains controversial in Germany, which is committed to closing its nuclear power plants. The ministers called for development of new energy technologies, but conceded that fossil fuels would "remain the basis of the world energy industry for at least the first half of the 21st century".

Atomic power was highlighted as a key alternative in the search for carbon-free energy. "For those countries that wish, wide-scale development of safe and secure nuclear energy is crucial for long-term, environmentally sustainable diversification of energy supply."

The draft statement issued by the Russian Energy Ministry, which does not yet reflect official G8 policy, notably failed to address the crisis in Ukraine in January, when Gazprom stopped the flow of gas to its neighbour after Ukraine refused to accept a price increase.

Neither Russia nor the United States showed any sign of willingness yesterday to ratify the Energy Charter, a treaty that seeks to establish a liberal regime in the transport and distribution of energy supplies. The acceptance among the G8 energy ministers of the need for a renewed focus on the delivery of more hydrocarbons and a new push for nuclear power is likely to please both the White House and the Kremlin, which has been pushing for a global monitoring system for the production and sale of nuclear fuel.



The original of this article has lots of lovely graphs in it that I have not endeavoured to reproduce below

This week Science Magazine's on-line SciencExpress reports that Antarctica has been losing large amounts of ice mass over the past three years, contributing to sea level rise at a rate of 0.4 ñ 0.2 mm/year. This comes on the heels of a paper published by Science two weeks ago that reported that Greenland was also losing big chunks of ice and contributing to sea level rise at a rate of 0.57 mm/yr.

If this sounds like one of those repeating news stories -- Coup in Haiti, Osama Sends a Tape, etc. -- it is. And so is the response. Natural variability is sufficiently large on yearly and multidecadal time scales that it is simply impossible to conclude that anything other than natural variability is at play in either of these two stories.

The SciencExpress paper by Isabella Velicogna and John Wahr reports on 34 months of data recorded by a new NASA satellite that measures the pull of gravity. Variations in the gravitational field are related to variations in the local mass beneath the satellite. If the mass changes, the satellite observes a different degree of gravitational pull.

Velicogna and Wahl attempted to use the gravity variations observed over Antarctica to determine whether Antarctica was gaining or losing mass. But, their analysis is complicated because variations in gravity can be caused by many things. These include variations in atmospheric pressure (the atmosphere has a certain mass); gravity signals arising from outside of Antarctica; and mass changes from a process known as post-glacial rebound -- slow, ongoing changes to the earth's crust as it adjusts to the removal of its huge ice load from the last ice age. Each of these effects needs to be correctly accounted for before estimating snow and ice changes. After this process, Velicogna and Wahr derived the time history of the variations in ice mass covering Antarctica (from April 2002 through August 2005) shown in Figure 1.

Additionally, the researchers calculated the ice mass changes for the two major ice sheets across Antarctica -- the Western Antarctic Ice Sheet (WAIS) and the Eastern Antarctic Ice Sheet (EAIS) -- which together cover the vast majority of the continent. Figure 2 shows that the there is no trend in the EAIS (which is about 3 times as large as the WAIS) and that virtually all of the mass loss is coming from the WAIS.

This differs from the results published by Davis et al. in Science magazine just last summer, which used a different satellite and over a longer time period -- May1982 through May 2003. While Davis et al. did find that the smaller WAIS was losing mass, they also found that the much larger EAIS was gaining mass at a rate that exceeded the loss over the WAIS. In total, Davis et al. found that Antarctica was gaining mass (from increased snow accumulation) and contributing to a decline in sea level of about 0.09 mm/yr. The differences between these two results likely lie somewhere in the collection of factors that include different time periods, different spatial coverages, and in analysis uncertainties.

However, one thing is clear. The beginning of the Velicogna and Wahl analysis occurs during an unusually high point in the longer record of Davis et al. (Figure 3). This means that the apparent decline in the record of Velicogna and Wahl may simply be a short term correction to an anomalously high mass gain during a period of long-term mass growth. But who is to know for sure? It is impossible to tell anything about a trend in a system as vast as Antarctica with less than three years worth of data.

Records of the extent of sea ice surrounding Antarctica are available from satellite observations starting back in the late 1980s. Figure 4 (from the National Snow and Ice Data Center) shows that there has been a slight increase in sea ice during the past two decades. Floating sea ice is a different system than the one being measured by either of the two studies mentioned above. Nevertheless it gives some indication as to what is going on in the environs of the extreme Southern Hemisphere. And it certainly doesn't look like ice is disappearing (notice, however, that there is a lot of variation on the yearly to multi-yearly scale).

So, all the Velicogan and Wahl results really demonstrate is that there are short term variations in the amount of ice and snow covering the Antarctic continent. Other data indicate that over the course of the past several decades at least, that the ocean-land system of Antarctica has been experiencing a growth in the amount of snow and ice there

There is nothing inherently noteworthy about the results of this three year study of Antarctic ice trends. This is not to disparage the scientific work of Velicogna and Wahl. It is to suggest that their paper serves more as a initial investigation into some of the applications of observations of gravitational variations, rather than bearing any relevance to the issue of global climate change and its implications.


(From CO2 Science Magazine, 8 March 2006)

Considerable fanfare was recently accorded the study of Rignot and Kanagaratnam (2005), when "using satellite radar interferometry observations of Greenland," they detected "widespread glacier acceleration." Calculating that this phenomenon had led to a doubling of "the ice sheet mass deficit in the last decade" and, therefore, a comparable increase in Greenland's contribution to rising sea levels, they went on to claim that "as more glaciers accelerate ... the contribution of Greenland to sea-level rise will continue to increase."

With respect to these contentions, we have no problem with what the two researchers have observed with respect to Greenland's glaciers; but we feel compelled to report that what they have calculated with respect to the mass balance of Greenland's ice sheet and what they say it implies about sea level are diametrically opposed to the story told by other more inclusive real-world data.

A simple introduction to the issue is provided by Dowdeswell (2005), who writes in an accompanying "perspective" piece that "the Greenland Ice Sheet gains mass through snowfall and loses it by surface melting and runoff to the sea, together with the production of icebergs and melting at the base of its floating ice tongues." Hence, it is perfectly clear, as he continues, that "the difference between these gains and losses is the mass balance; a negative balance contributes to global sea-level rise and vice versa."

Where Rignot and Kanagaratnam went wrong was in estimating Greenland's mass gain via snowfall over the vast interior of the ice sheet during the time that coastal glaciers were accelerating. Instead of relying on measurements for this evaluation, they relied on the calculations of Hanna et al. (2005), who used meteorological models "to retrieve annual accumulation, runoff, and surface mass balance."

When actual measurements of the ice sheet via satellite radar altimetry are employed, quite a different perspective is obtained. Zwally et al. (2005), for example, found that although "the Greenland ice sheet is thinning at the margins," it is "growing inland with a small overall mass gain." In fact, for the 11-year period 1992-2003, Johannessen et al. (2005) found that "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," but that "an increase of 6.4 ñ 0.2 cm/year is found in the vast interior areas above 1500 meters." Spatially averaged over the bulk of the ice sheet, the net result, according to the latter researchers, was a mean increase of 5.4 ñ 0.2 cm/year, "or ~60 cm over 11 years, or ~54 cm when corrected for isostatic uplift."

Consequently, and in direct contradiction of the claim of Rignot and Kanagaratnam, Greenland has experienced no "ice sheet mass deficit in the last decade." Quite to the contrary, it has been host to a net accumulation of ice, which Zwally et al. find to be "contributing -0.03 ñ 0.01 mm a-1 to sea-level change." As a result, the net accretion of ice on Greenland over the past decade has actually been ever so slightly lowering global sea level.

As for the future, whereas Rignot and Kanagaratnam contend that "as more glaciers accelerate ... the contribution of Greenland to sea-level rise will continue to grow," Zwally et al. report that "thinning at the margins of the Greenland ice sheet and growth at higher elevations is an expected response to increasing temperatures and precipitation in a warming climate," and this observation suggests that Greenland's accreting-ice trend of the last decade would likely continue in a warming world, which is once again just the opposite of what Rignot and Kanagaratnam contend.

In light of these several observations, it is a sad commentary on the politicization of science that the American Association for the Advancement of Science's press release about the Rignot and Kanagaratnam paper was entitled "Greenland glaciers dumping ice into Atlantic at faster pace." Although technically correct, it failed to convey the far more important knowledge that earth's hydrologic cycle was sucking water out of the ocean and depositing it on Greenland in the form of snow at an even faster pace.


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

Comments? Email me here. My Home Page is here or here. For times when is playing up, there are mirrors of this site here and here.


No comments: