Natural Heat Vent May Counter
Things have really been tough these days for the proponents of the global warming theory.
It's not just that President George W. Bush rejected the Kyoto global warming accord, the Clinton-era treaty which mandated economically drastic cuts in greenhouse gas emissions.
Science has not exactly been kind, either. It seems that not a month goes by when there is yet another scientific study casting serious doubts about environmentalists' belief that man-made carbon dioxide emissions will lead to catastrophic global warming in coming decades.
Just recently, a team of scientists led by Dr. Richard Lindzen of the Massachusetts Institute of Technology published a paper in which they theorize that there could be a natural "vent" in the Earth's atmosphere that releases heat into space. The authors caution that more research needs to be done to verify the phenomenon. But they say that, if true, the existence of a de facto atmospheric thermostat that helps keep the Earth's temperature on an even keel would require global warming theorists to significantly scale back their predictions of warming allegedly caused by the buildup of greenhouse gases.1
The study, published in the March 2001 issue of the Bulletin of the American Meteorological Society, examines the behavior of high cirrus clouds over a large section of the western tropical Pacific Ocean. Clouds have been one of the most difficult factors for climate modelers to understand in their efforts to predict long-term temperature trends - and why climate model predictions so often prove wrong. For instance, thick clouds reflect more sunlight than thin clouds back into space and help mitigate surface warming. Thin clouds, on the other hand, don't deflect as much sunlight but are efficient in trapping heat at the surface.2
Lindzen is critical of climate modelers for failing to take into account the complex role of clouds in regulating temperature: "We found that there were terrible errors about clouds in all the models, and that that will make it impossible to predict" long-term temperature change.3
The significance of Lindzen's new study is that scientists may have found how those thin, high cirrus clouds specifically help to regulate global temperatures - and serve as a counter to global warming. The study finds that high cirrus clouds decrease in thickness by about 22% per one degree Celsius increase in sea surface temperature. Conversely, the cirrus clouds thicken when the sea surface temperature is lower. Most intriguing, a 22% decrease in cirrus cloud cover also leads to a significant decrease in sea surface temperature of about 1.1°C. In short, the study says that cirrus clouds operate much like the "iris" of an eye regulating the admission of light. The clouds open in response to rising surface temperature, permitting cooling. The clouds close when the surface temperature cools to retain heat.4
The study's authors say that these findings require climate modelers to scale back by as much as two-thirds the projected warming that would result from a doubling of carbon dioxide. According to some climate model forecasts, a doubling of carbon dioxide in the atmosphere would lead to a 1.2°C temperature increase. But the existence of the atmospheric heat "vent" should change that prediction to between 0.57° and 0.83°C.5
Lindzen says that the study's results as well as scientific evidence on other natural climate processes should give global warming theorists considerable pause before recommending economically-drastic measures, such as the Kyoto Treaty, to combat the unproven man-made warming threat.
Speaking bluntly, Lindzen says that, in view of the paucity of evidence for human-driven climate change, "the Kyoto Treaty is absurd."6
The possible existence of an atmospheric heat vent that mitigates global warming is not the first time scientists have discovered a natural phenomenon that influences climate change. Many scientists believe changes in solar magnetism cause significant increases and decreases in the Earth's temperature. Dr. Sallie Baliunas of the Harvard Smithsonian Center for Astrophysics says that increases and decreases in the Earth's temperature over the last 250 years "match almost exactly the ups and downs in [solar] magnetism."7
Other scientists point to changes in ocean temperature and changes in ocean circulation patterns over decades or even centuries as other likely contributors to global warming and cooling.8
Whatever the respective roles of the sun, the oceans and an
atmospheric heat vent, one thing is certain: The evidence that
natural forces influence climate change is rapidly accumulating.
1 Dr. Richard Lindzen, Dr. Ming-Dah Chou and
Dr. Arthur Hou, "Does The Earth Have An Adaptive Infrared
Iris?," Bulletin of the American Meteorological Society,
Vol. 82, No. 3, March 2001.
2 "Natural 'Heat Vent' In Pacific Cloud Cover Could Diminish Greenhouse Warming," Press Release, NASA Goddard Space Flight Center, February 28, 2001.
3 James Glassman, "Kyoto 'Absurd' Says MIT Scientist," Interview of Dr. Richard Lindzen, Tech Central Station, March 5, 2001.
4 Lindzen, et al.
6 "Kyoto 'Absurd' Says MIT Scientist."
7 James Glassman, "Here Comes The Sun To Further Cloud Global Warming Theory," Interview of Dr. Sallie Baliunas, Tech Central Station, April 23, 2001.
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John K. Carlisle is director of The National Center for Public Policy Research's Environmental Policy Task Force. He can be reached at JCarlisle@nationalcenter.org.
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