From A Test of Our Character ($):
There's some dispute among economists over how forcefully we should act to curb greenhouse gases, but there's broad consensus that even a very strong program to reduce emissions would have only modest effects on economic growth. At worst, G.D.P. growth might be, say, one-tenth or two-tenths of a percentage point lower over the next 20 years. And while some industries would lose jobs, others would gain.
Is this true? I've always thought that a "very strong program" would have economic growth implications larger than 0.2%. The reputable estimates of macro impacts from Kyoto were larger than that, up to 0.5% of GDP. Maybe new technology has trimmed the cost estimates? Still, 0.2% of a $12 trillion economy is a $24 billion cost.
My go to benefit estimate of Kyoto is $20 billion so the net benefits aren't so negative with Krugman's cost estimate. And, $20 billion is at the low end of the range of estimates. And, with scientific consensus, I'm ready to re-evaluate my use of the very lowest benefit estimate out there.