A comparison of tropical temperature trends with model predictions
David H. Douglass 1 *, John R. Christy 2, Benjamin D. Pearson 1, S. Fred Singer 3 4
1Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627, USA
2Department of Atmospheric Science and Earth System Science Center, University of Alabama in Huntsville, Huntsville, AL 35899, USA
3Science and Environmental Policy Project, Arlington, VA 22202, USA
4University of Virginia, Charlottesville, VA 22903, USA
We examine tropospheric temperature trends of 67 runs from 22 Climate of the 20th Century model simulations and try to reconcile them with the best available updated observations (in the tropics during the satellite era). Model results and observed temperature trends are in disagreement in most of the tropical troposphere, being separated by more than twice the uncertainty of the model mean. In layers near 5 km, the modelled trend is 100 to 300% higher than observed, and, above 8 km, modelled and observed trends have opposite signs. These conclusions contrast strongly with those of recent publications based on essentially the same data.
" “The observed pattern of warming, comparing surface and atmospheric temperature trends, does not show the characteristic fingerprint associated with greenhouse warming. The inescapable conclusion is that the human contribution is not significant and that observed increases in carbon dioxide and other greenhouse gases make only a negligible contribution to climate warming. Satellite data and independent balloon data agree that atmospheric warming trends do not exceed those of the surface. Greenhouse models, on the other hand, demand that atmospheric trend values be 2-3 times greater. We have good reason, therefore, to believe that current climate models greatly overestimate the effects of greenhouse gases. Satellite observations suggest that Greenhouse models ignore negative feedbacks, produced by clouds and by water vapour, that diminish the warming effects of carbon dioxide.”