From “The Science is Settled” Department. Climate sensitivity is the biggest unknown in climate research. If climate sensitivity is low, then increasing CO2 levels are a non-problem. The IPCC claims that sensitivity is high and that therefore regulating emissions is necessary.
However, a new paper by Dr Roy Spencer and William Braswell, based on real world observations rather than incomplete models, claims that determination of sensitivity is as yet unsolved, because of the difficulty in distinguishing forcings and feedbacks:
“While the satellite-based metrics for the period 2000–2010 depart substantially in the direction of lower climate sensitivity from those similarly computed from coupled climate models, we find that, with traditional methods, it is not possible to accurately quantify this discrepancy in terms of the feedbacks which determine climate sensitivity. It is concluded that atmospheric feedback diagnosis of the climate system remains an unsolved problem, due primarily to the inability to distinguish between radiative forcing and radiative feedback in satellite radiative budget observations.”
The paper is technical, but its conclusion shows that anyone who says “the science is settled” is either ignorant or wilfully deceptive.
Download it here (PDF).