“Earth itself is telling us there’s nothing to worry about in doubled, or even quadrupled, atmospheric CO2″

WUWT
"The major assumption used for this analysis, that the climate of the early part of the 20th century was free of human influence, is common throughout the AGW literature. The second assumption, that the natural underlying warming trend continued through the second half of the last 130 years, is also reasonable given the typical views expressed about a constant natural variability. The rest of the analysis automatically follows.

In the context of the IPCC’s very own ballpark, Earth itself is telling us there’s nothing to worry about in doubled, or even quadrupled, atmospheric CO2."