Jeff Goodell interviews Dr. David Keith on geoengineering. Dr. Keith is a leading proponent of albedo modification techniques.
"The central argument has to do with the uncertainty that has persisted
for decades and still does about just how bad the climate problem is.
It comes down to a parameter that climate scientists call “climate
sensitivity” — how much the climate will warm if we, say, double the
amount of CO2 in the air. And the answer is that's still uncertain by
factors of two or three, which is just gigantic. So if we are very
lucky, it might be that we could double or triple the amount of CO2 in
the air and have relatively small climate change, some of which might
On the flip side, if we're unlucky, we might see 5 or 6 degrees
[Celsius] globally — and you can double that if you're in the middle of
a mid-latitude continent — which is just stunning. That's as big as the
change between the glacial and the interglacial state and that would
certainly, over a few hundred years, melt big sections of the ice caps.
It’s really quite horrific stuff. And we don't know which of those two
it is, and we're not going to know in time.
So we're making decisions every day by continuing to put CO2 in the air
— decisions that we cannot easily reverse. And so the culmination of
the CO2 in the air, and that uncertainty about how dangerous it is,
that means you need a backup plan.