Global Science Report is a weekly feature from the Center for
the Study of Science, where we highlight one or two important
new items in the scientific literature or the popular media. For
broader and more technical perspectives, consult our monthly
“Current Wisdom.” As promised, we report here on yet another
published estimate of the earth’s equilibrium climate
sensitivity that is towards the low end of the United Nations’
Intergovernmental Panel on Climate Change (IPCC) range of
possibilities. Recall that the equilibrium climate sensitivity
is the amount that the earth’s surface temperature will rise
from a doubling of the pre-industrial atmospheric concentration
of carbon dioxide. As such, it is probably the most important
factor in determining whether or not we need to “do something”
to mitigate future climate change. Lower sensitivity means low
urgency, and, if low enough, carbon dioxide emissions confer a
net benefit. And despite common claims that the “science is
settled” when it comes to global warmin