Radiative Forcing

Calculations based on these considerations are used to produce Figure 8 that takes into account the effect of greenhouse gases that humans have put into the atmosphere since the Industrial Revolution.

Their radiative forcing effects are expressed in Wm^-2decade^-1 for five different periods, ending with the decade of the 1980s. Note that forcing due to carbon dioxide has increased but not directly in proportion to its increased concentration, as previously discussed. The impacts of others, such as the CFCs and HCFCs, have increased more dramatically even though their abundance is very low, because their impact per molecule is high and their lifetimes are large.

Note that the magnitude of the increase in radiative forcing for the most recent decade on the previous graph is about 0.55 Wm^-2 (Figure 9). The total cumulative radiative forcing since the Industrial Revolution due to anthropogenic greenhouse gases is about 2.77 Wm^-2.

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