Hi Michael,
I would like to defend Ken on this matter. SRM-type geoengineering is the
only kind of intervention which could cool the planet straightaway. We are
already cooling the planet with our SO2 emissions associated with
coal-fired power stations, but not sufficiently to offset global
In theory, I would have thought a rapid drop in CO2 emissions should cause
global temperatures to drop pretty quickly, as ocean uptake will remove a
lot of historical emissions. You'd have to keep sulphur emissions constant
for this to happen, though.
Choosing whether to maintain sulphur
Plot is from Cao et al, 2011. Zeroing emissions does cause CO2 to drop
somewhat, but the climate is not yet in equilibrium with current CO2 levels, so
the net effect is roughly constant temperature, all else being equal.
From: geoengineering@googlegroups.com