New study finds low climate sensitivity
Jan 25, 2013
Bishop Hill in Climate: sensitivity

Via Leo Hickman, more evidence that aerosols have a small impact and that climate sensivity is low.

When the researchers at CICERO and the Norwegian Computing Center applied their model and statistics to analyse temperature readings from the air and ocean for the period ending in 2000, they found that climate sensitivity to a doubling of atmospheric CO2 concentration will most likely be 3.7°C, which is somewhat higher than the IPCC prognosis.

But the researchers were surprised when they entered temperatures and other data from the decade 2000-2010 into the model; climate sensitivity was greatly reduced to a "mere" 1.9°C.

Professor Berntsen explains the changed predictions:

"The Earth's mean temperature rose sharply during the 1990s. This may have caused us to overestimate .

"We are most likely witnessing natural fluctuations in the – changes that can occur over several decades – and which are coming on top of a long-term warming. The natural changes resulted in a rapid global in the 1990s, whereas the natural variations between 2000 and 2010 may have resulted in the levelling off we are observing now."

I wonder how much more evidence we need of low climate sensitivity before policymakers are forced to take notice?

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