Making the Data Fit the Model; Soot May Pose More Problems than Previously Thought

Making the Data Fit the Model

Science magazine claimed, "A stubborn argument against global warming may be discredited by a re-analysis of the data central to its claims," when it published, via Scienceexpress.org, a paper by Benjamin Santer of the Lawrence Livermore National Laboratory in California on May 1. Santers team was tackling the well-known argument that atmospheric temperature data from satellites fail to show the warming trend found in surface level observations. By comparing a new dataset to a model that predicts warming in the troposphere, he was able to claim that his team had detected a warming trend of 0.1 degrees Celsius per decade.

This is considerably above the level of +/- 0.05 degrees C per decade previously accepted as demonstrated by the satellite data. The standard dataset is produced by a team at the University of Alabama in Huntsville (UAH), led by John Christy. The new dataset, produced by Frank Wentz of Remote Sensing Systems (RSS) of Santa Rosa, California, is based on the idea that variations between satellites and their orbits can cause variations in the data that need to be accounted for. The RSS data remain unpublished, however, and Christys team has amended its data to account for the factors highlighted by Wentz.

The new study by Santer is based on the idea that there must still be something wrong with the UAH dataset because it fails to match the consequences for the troposphere proposed by the climate model Santer uses. That model appears to predict consequences for the stratosphere quite accurately. Because the RSS data match the predicted warming trend better, Santer suggests that the failure to find a warming trend in the UAH data may be due "an artifact of data uncertainties."

Christy, however, was already undertaking a rigorous analysis of the UAH data to estimate its error range. His re-examination was published in the May 2003 Bulletin of the American Meteorological Society. By comparing the satellite data to independent data obtained from weather balloons, he was able to re-affirm the reliability of the UAH data. Santers paper suggested that there might be a problem with the balloon data as well.

Christy cast doubt on the reliability of Santers model, telling Reason magazine science correspondent Ron Bailey, "Its a lot easier to model the stratosphere because you only have to consider radiational effects. The troposphere is much messier. It contains complicated things likes clouds, convection, moisture and dust."

He went on to tell the Oakland Tribune, "It does not bother me that our data do not agree with their virtual model of the world Its a curious way to do science, to use a model to verify data rather than the other way around. If you follow this too far down that road, youre in danger of saying, Its my theory thats correct and the real world thats wrong." (Ron Bailey, Tech Central Station, May 1).

Soot May Pose More Problems than Previously Thought

The IPCCs Third Assessment Report issued in 2001 argued that "sulfate aerosol" emissions from burning coal helped cool the atmosphere, accounting for the lower than expected warming trend so far detected. Further research, however, from such individuals as James Hansen of the Goddard Institute for Space Studies, suggested that the presence of "black carbon" aerosols soot raises atmospheric temperatures as the particles absorb solar radiation. It was initially thought that the cooling effect of sulfate aerosols and the warming effect of black carbon cancelled each other out.

Hansen and his colleagues published further research on the subject in the May 13 issue of the Proceedings of the National Academy of Sciences. The paper looked at how smoke and other black carbon in the atmosphere interacts with sunlight and chemicals to contribute to climate change. The research team, from NASA, Columbia University and Lawrence Berkeley National Laboratory, found that "a rapid rise in worldwide temperatures over the last 50 years may be largely due to smoky particles in the air."

Co-author and NASA scientist Dorothy Koch told the Los Angeles Times, "All black carbon does is absorb sunlight If you put more into the atmosphere, you increase the warming." Other experts, like Stanford University climatologist and leading global warming alarmist Stephen Schneider, urged caution.

The study speaks directly to one of the central issues surrounding the adoption or rejection of the Kyoto Protocol. One reason the administration has given for rejecting the deal is the large accumulation of atmospheric pollutants over southern Asia known as the "Asian Brown Cloud." The presence of the two-mile thick phenomenon appears to be due to forest fires, the burning of wood and dung in stoves and in the increased use of fossil fuels in developing countries. The Kyoto Protocol exempts developing countries from having to reduce their emissions from such sources. (Greenwire, May 6 2003).

Announcement

With this issue, Iain Murray becomes Managing Editor of Cooler Heads. He has also joined CEI as a Senior Fellow in Environmental Policy. Iain was formerly Director of Research at the Statistical Assessment Service, where he examined a wide range of scientific problems in public policy and the media.

Iain writes regularly for Techcentralstation.com and for United Press International. As a British citizen, he worked for the UK Department of Transport on railroad privatization before coming to the US in 1997. He holds an MA from Oxford University, an MBA from London University, and the Diploma of Imperial College of Science, Technology, and Medicine.

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