Atmospheric CO2: Principal Control Knob Governing Earth’s Temperature" by Andrew A. Lacis,* Gavin A. Schmidt, David Rind, and Reto A. Ruedy, Science, Vol. 330, No. 6002 (15 October 2010)

Science (15 October 2010), Vol. 330, No. 6002, pp. 356-359; DOI: 10.1126/science.1190653

Atmospheric CO₂: Principal Control Knob Governing Earth’s Temperature

Andrew A. Lacis,^* Gavin A. Schmidt, David Rind, and Reto A. Ruedy

Abstract

Ample physical evidence shows that carbon dioxide (CO₂) is the single most important climate-relevant greenhouse gas in Earth’s atmosphere. This is because CO₂, like ozone, N₂O, CH₄, and chlorofluorocarbons, does not condense and precipitate from the atmosphere at current climate temperatures, whereas water vapor can and does. Noncondensing greenhouse gases, which account for 25% of the total terrestrial greenhouse effect, thus serve to provide the stable temperature structure that sustains the current levels of atmospheric water vapor and clouds via feedback processes that account for the remaining 75% of the greenhouse effect. Without the radiative forcing supplied by CO₂ and the other noncondensing greenhouse gases, the terrestrial greenhouse would collapse, plunging the global climate into an icebound Earth state.

NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025, USA.

^*Correspondence e-mail: andrew.a.lacis@nasa.gov

Link: