Figure 23.27Three scenarios or “representative concentration pathways” (RPCs) projected by the IPCC for carbon dioxide, methane, and nitrous oxide during the twenty-first century. Scenario A (red line) implies continuing high rates of fossil-fuel burning (RCP8.5); scenario B (green line) implies stabilization of emission rates in the latter part of the twenty-first century (RCP6); scenario C (blue line) implies a rapid conversion to nonfossil fuels (RCP2.6).