I didn't read through the whole "what is the Libertarian solution to Global Warming" thread, so excuse me if I'm saying what somebody else has said.
And I'm not a climate scientist (although I am married to a geologist who is a professor in the same department as Ray Bradley and several other world-class climate scientists), so I can't assess the scientific literature and pick apart various estimates of CO2 sensitivity or urban heat island effects on weather stations or ...
But it seems to me pretty clear that there is a clear consensus among scientists that Global Warming is happening and we're almost certainly the cause.
So the question for me becomes: how big a deal is it, for both people and our environment?
According to the climate scientists, we've
been warming for 100 years now, and nobody seemed to notice.
I know there are worries that there will be a 'climate tipping point' -- that warming will shut down the gulf stream or make the Greenland Ice Sheet fall into the ocean all at once or ocean chemistry changes will make all that methane down there suddenly bubble up to the surface. I'd be very interested in evidence that any of those things have ever happened in the past (because on a geological time scale the Earth's climate has varied a LOT).
And I'm certain warming will be bad for some species-- maybe polar bears will go extinct. Then again, a warmer environment will be good for some species, and I recently read an interesting article about new species arising to fill empty ecological niches much more quickly than biologists expected (I dont' remember the details, but they were seeing new species arise over a period of decades instead of centuries or millenia). I think we all (biologists included) have a bias towards species that already exist, and have trouble having faith in Nature's ability to adapt.
So given that the world was a MUCH warmer place back when the dinosaurs were roaming around, and given that most people most places in the world didn't even notice an almost 1° C rise in temperature over the last century, I just don't think it will be a global catastrophe.
Which is a good thing, because I don't think the kind of global agreement that would be required to reduce carbon emissions has any realistic chance of happening-- the incentives for a country or region to cheat (and burn lots of cheap fossil fuels) are just too great.
