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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 forego 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.