OK, we've beaten this to death with facts, suppositions, and worse. How
about a new direction.

Forget global warming. Whether or not it exists and if it does how much
we contribute to it. Take a look at what else our pollution has caused.

Acid rain:

http://www.epa.gov/acidrain/what/index.html

Or ocean acidification:

http://www.pmel.noaa.gov/co2/story/Ocean+Acidification

I don't think there's much controversy over the fact that our carbon
emissions are causing these. Even disregarding global warming, the
effects of these would seem sufficient reason to curb air pollution.

What reminded me of this was an article in this mornings paper about the
failure of oysters to breed in Pacific Northwest waters due to increased
acidity. See:

http://www.spokesman.com/stories/201...fication-puts-
pressure-on-oyster/

I await the inevitable "it's not our fault" chorus from the usual
suspects :-).

--
Intelligence is an experiment that failed - G. B. Shaw