Effects of elevated CO₂ and climate variables on plants

Excerpt

CO₂ concentration of the atmosphere is increasing, and climate modelers have predicted a consequent global warming and changes in precipitation patterns. The report of the Intergovernmental Panel on Climate Change edited by Houghton et al. (8) projects CO₂ increasing from present day concentrations of about 350 μL/L (1 μL/L = 1 microliter CO₂ per liter of air = 1 ppmv = 1 part per million by volume = 1 μmol/mol) to more than 800μL/L by the end of the next century if no steps are taken to limit emissions. They predict this increase in CO₂ plus that of other radiatively active “greenhouse” gases—methane, nitrous oxide, chlorofluorocarbons (CFC's), ozone—would cause an increase in global mean temperature of about 4.2°C. (40°F). Some regions probably will receive increases in precipitation, whereas others will receive less. This increase in CO₂ and possible concomitant climate change could affect the ecology of most living things, including production agriculture. However, the increasing CO₂ concentration also will directly affect growth of all plants whether the climate changes or not. …