CR 10:69-82 (1998)  -  doi:10.3354/cr010069

Over the course of the past 2 decades, I have analyzed a number of natural phenomena that reveal how Earth's near-surface air temperature responds to surface radiative perturbations. These studies all suggest that a 300 to 600 ppm doubling of the atmosphere's CO₂ concentration could raise the planet's mean surface air temperature by only about 0.4°C. Even this modicum of warming may never be realized, however, for it could be negated by a number of planetary cooling forces that are intensified by warmer temperatures and by the strengthening of biological processes that are enhanced by the same rise in atmospheric CO₂ concentration that drives the warming. Several of these cooling forces have individually been estimated to be of equivalent magnitude, but of opposite sign, to the typically predicted greenhouse effect of a doubling of the air's CO₂ content, which suggests to me that little net temperature change will ultimately result from the ongoing buildup of CO₂ in Earth's atmosphere. Consequently, I am skeptical of the predictions of significant CO₂-induced global warming that are being made by state-of-the-art climate models and believe that much more work on a wide variety of research fronts will be required to properly resolve the issue.

Carbon dioxide · CO₂ · Climate change · Global warming · Greenhouse effect