David H Douglass
Dr David H Douglass Professor of Physics at the University of Rochester and a real climate scientist. As such he is frequently quoted as a genuine expert along with colleagues Richard Lindzin, John R. Christy, S. Fred Singer and Roger Pielke, who he has co-published papers with or issued criticism of climate science.
Douglass regularly publishes climate related science papers but the main paper quoted by deniers dates back from 2007 where he is cited as the lead author.
- A comparison of tropical temperature trends with model predictions David H. Douglass, John R. Christy, Benjamin D. Pearson, S. Fred Singer Int. J. Climatol. (2007) DOI: 10.1002/joc.1651. DOI: 10.1260/095830509787689277.
The basis of the paper which was a review of data rather actual collection comes to a simple conclusion that the expected ‘hotspot’ in the atmosphere at the tropics was not there and so therefore climate change predictions or rather models [which expected a hotspot] were wrong. However the paper was criticised for several issues not least the fact that it was wrong.
Dr Ben Santer , Dr Tom Wigley and 15 other colleagues, have published a new paper in the International Journal of Climatology on this very issue. It thoroughly quashes the Evan’s claim, and also hammers the related critiques of climate science, by Dr David Douglass, Dr John Christy, Dr Benjamin Pearson and Dr S. Fred Singer, which claimed a significant discrepancy between theory and observations in terms of the warming of the lower atmosphere. What’s particularly good news for the large non-scientific community who has interest in science behind these issues, is that the paper’s authors have also put together a FAQ. In it, they explain, using non-technical language, all the key sceptical arguments on this issue, and the latest evidence. The figure above is from the fact sheet. I’ll just quote a couple of key points from it:
Using state-of-the-art observational datasets and results from a large archive of computer mode simulations, a consortium of scientists from 12 different institutions has resolved a long-standing conundrum in climate science – the apparent discrepancy between simulated and observed temperature trends in the tropics. Research published by this group indicates that there is no fundamental discrepancy between modeled and observed tropical temperature trends when one accounts for: 1) the (currently large) uncertainties in observations; 2) the statistical uncertainties in estimating trends from observations. These results refute a recent claim that model and observed tropical temperature trends “disagree to a statistically significant extent”. This claim was based on the application of a flawed statistical test and the use of older observational datasets.
The bottom line is that we obtained results strikingly different from those of Douglass et al. The “robust statistical test” that they used to compare models and observations had at least one serious flaw – its failure to account for any uncertainty in the “signal component” of observed temperature trends (see QUESTION 7). This flaw led them to reach incorrect conclusions. We showed this by applying their test to randomly generated data with the same statistical properties as the observed temperature data, but without any underlying “signal trend”. In this “synthetic data” case, we knew that significant differences in temperature trends could occur by chance only, and thus would happen infrequently. When we applied the Douglass et al. test, however, we found that even randomly generated data showed statistically significant trend differences much more frequently than we would expect on the basis of chance alone. A test that fails to behave properly when used with random data – when one knows in advance what rresults to expect – cannot be expected to perform reliably when applied to real observational and model data.
Go read the whole thing (there are 10 frequently-asked-questions answered in all).