Roy Spencer: Has the Climate Sensitivity Holy Grail Been Found?

Global Warming: Has the Climate Sensitivity Holy Grail Been Found?

This article addresses new satellite and modeling evidence that previous satellite diagnoses of high climate sensitivity--which directly translate into predictions of dangerous levels of global warming--contain a large spurious bias. It is shown that those exaggerated estimates were the result of faulty assumptions regarding clouds when analyzing variations in average global temperature and average reflected sunlight off of the Earth.

Specifically, it has been assumed (explicitly or implicitly) that, for global averages on time scales of three months or more, temperature variations cause clouds to change, but that cloud variations do not cause temperature to change. But when properly filtered, the satellite data reveal evidence of cloud variations indeed causing temperature changes, and that this source of natural climate variability biases the estimate of climate sensitivity in the direction of a very sensitive climate system.