With Speed and Violence Fred Pearce - Global Commons Institute

indirectly, it was almost certainly not responsible for most of the rapid
global warming seen over the past three decades."
For that most recent period, he says, it is clear that rising concentrations
of greenhouse gases are the primary driver. But besides producing a general
global warming, they have generated changes in the stratosphere that have
produced a specific positive feedback to warming in the polar regions and
the midlatitudes. The positive feedback has manifested itself through the
apparently natural Arctic Oscillation and the SAM—cycles that appear to
have gone into overdrive.
Only a fool would conclude from this that we don't need to worry so much
about man-made climate change. On the contrary, Shindell's dramatic
discovery of the stratospheric feedback suggests that the natural processes of
temperature amplification are much stronger than those in most existing
climate models. His newly discovered feedback seems set to continue,
driving up temperatures in Arctic regions beyond the levels previously
forecast. That additional warming is likely to unleash other feedbacks that
will melt ice, raise sea levels, release greenhouse gases trapped in permafrost
and beneath the ocean bed, and perhaps cause trouble for the ocean
conveyor.
Relieved? I don t think so.