And what should that tell us?
The IPCC’s official total temperature increase since 1850 has gone from .6Â° Celsius to .76Â° C (or about 1.4Â° Fahrenheit).
The Fourth Assessment also explains that, “For the next two decades a warming of about 0.2Â° C per decade is projected for a range of [emission scenarios]. Even if the concentrations of all greenhouse gases and aerosols had been kept constant at year 2000 levels, a further warming of about .1Â° C per decade would be expected.”
Their best estimate for a low emissions scenario is still a temperature increase of 1.8Â° C by 2100. Their best estimate for a worst case emissions scenario projects 4.0Â° C — and recent research suggests that would give us sea level rise of 6 inches a decade in 2100.
Whaddya say we try to stick with the low emissions scenario?