Equilibrium global average temperature increase above pre-industrial (oC) vs greenhouse gas concentration stabilization level (ppm CO2-eq). Plot represents Charney’s (1979) climate sensitivity relation of 3±1.5oC and red squares regions of Pagani et al.’s (2010) early and mid-Pliocene climate sensitivity relations. Colored zones I to VI represent various CO2 stabilization targets | “Charney 1979 Climate Senstivity” is about 3oC for a doubling of CO2. The range shown is for climate sensitivities of 1.5 to 4.5. |