The Current Wisdom is a series of monthly articles in which Patrick J. Michaels, director of the Center for the Study of Science, reviews interesting items on global warming in the scientific literature that may not have received the media attention that they deserved, or have been misinterpreted in the popular press.
In this Current Wisdom we report further on our ongoing effort to prepare comments on the latest, greatest (or, more aptly, most recent, most indecent) edition of the government’s assessment of climate change impacts in the United States (if you are interested in submitting your own comments, you should hurry, because the public comment period closes on this Friday, April 12).
A disturbing yet ubiquitous aspect of the current draft National Climate Assessment (and for that matter, both earlier editions of the NCA) is the use of future projections of climate change before demonstrating that they work in the recent past, as greenhouse-gas concentrations have increased.
Discussions of future impacts from changes in precipitation resulting from human emissions of greenhouse gases are everywhere in the report and they are usually bad—increased droughts, floods, and longer dry spells, for example. The NCA folks weren’t quite so enthusiastic at generating many forecasts of salutary changes. Perhaps Dr. Pangloss is their spiritual adviser.
NCA’s precipitation forecasts turn out to be uglier than Candide’s fair Cunegonde became. Do the models accurately simulate past changes that have been observed? If the answer is “no,” then the whole impact exercise is meaningless because the models provide no reliable information about what the future may bring.
The answer isn’t just “no.” It’s NO, NON, ONAY, NEIN.