Not exact matches
(Somewhat lower and higher
estimates of aerosol forcing and
sensitivity are found using other, arguably less
reliable, temperature datasets.)
I tend to believe that including the recent years will, indeed, lower the best
estimate of climate
sensitivity and, hopefully, allow for a more
reliable upper limit.
This is an example
of energy transport affecting the energy balance and a valid argument by itself that the paleo records aren't a
reliable way to
estimate current climate
sensitivity, isn't it?
Fred — I don't think that the Gregory 02 lower bound
estimate of sensitivity is at all
reliable, because it is highly sensitive to the particular values
of the ocean heat and forcings data used.
Using short records with uncertain forcings
of the Earth system that is not in equilibrium does not (yet) produce
reliable estimates of climate
sensitivity.»
In their 2008 JGR paper, Gregory and Forster focused on transient climate
sensitivity (TCR, representing the climate response to 1 % annual CO2 increases up to a CO2 doubling) as a more
reliable indicator
of the climate response to CO2 than the more uncertain climate
sensitivity estimates.
Furthermore it's not necessary to have
reliable estimates of the climate
sensitivity, it's enough to have moderate evidence to support the expectation
of significant warming.