So, Reuters took a look at the EPA’s economic analysis of the Lieberman-McCain Climate Stewardship Act (so I didn’t have to!). In case your memory is hazy, the CSA is a cap-and-trade bill that would cut emissions 65% by 2050. Here’s the nut:

The EPA found that the Climate Stewardship and Innovation Act of 2007 would shave up to 1.6 percent, or $419 billion, off a baseline forecast for U.S. gross domestic product in 2030 and up to 3.2 percent, or $1.332 trillion, by 2050.

That is, by any reasonable measure, a modest price to pay. Even so, I bet it overestimates the cost.

I’ll offer this open wager to anyone willing to take it. I’ll bet $1,000 (which is rich for me, believe me) that if a cap-and-trade similar to or stronger than the CSA is implemented by 2012, the net effect on GDP will be a positive in 2030 .