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item Idso, Sherwood

Submitted to: Nature Magazine
Publication Type: Review Article
Publication Acceptance Date: 2/15/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary: The rising carbon dioxide content of Earth's atmosphere is perceived by many to be a threat of unprecedented proportions, due to its produced potential to induce catastrophic global warming via an intensification of the atmosphere's greenhouse effect. However, anlayses of a number of natural phenomena suggest that the climatic effect of atmospheric CO2 has been seriously overestimated. This paper reviews those studies and identifies several planetary cooling forces that tend to curtail global warming. Some of these cooling forces can be intensified by the strengthening of biological processes that are enhanced by the aerial fertilization effect of atmospheric CO2 enrichment. This phenomenon thus provides a means whereby the rising carbon dioxide content of the atmosphere may nullify much of its own warming effect. The likely net result is a future of minimal CO2-induced global warming, which suggests that humanity need not fear the buildup of this trace component of the atmosphere that provides the primary raw material for essentially all food produced on earth.

Technical Abstract: Analyses of a number of natural phenomena that reveal how Earth's near-surface air temperature responds to surface radiative perturbations suggest that a 300 to 600 ppm doubling of the atmosphere's CO2 concentration may raise mean global air temperature by approximately 0.4 degree C. Much of this 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. Since several of these cooling forces have been estimated to be of equivalent magnitude, but of opposite sign, to the greenhouse effect of a doubling of the air's CO2 content, it is possible that little net temperature change will ultimately occur from the ongoing buildup of CO2 in Earth's atmosphere.