Energy Demand Scenarios

This book and Volume 2 are motivated by the need to stabilize atmospheric CO₂ at a concentration of no more than 450ppmv. A CO₂ concentration of450ppmv, when combined with the heating effect of other GHGs, would correspond to an equivalent concentration (in terms of changes in climate) of 560ppmv — that is, a doubling of the pre-industrial concentration of 280ppmv CO₂. This assumes that there are stringent reductions in the emissions of other GHGs (such as methane, N₂O and the halocarbons) or of gases (such as nitrogen oxides, carbon monoxide and reactive hydrocarbons) that react to form ozone, another GHG. If emissions of these other GHGs or GHG precursors are not sharply reduced, a mere 450ppmv CO₂ concentration would correspond to more than a doubling in terms of eventual climate warming.