Mr. Landsburg,

How unfortunate there are people such as yourself, who reduce everything to cost. hmmmm...maybe, as you're thinking of the economic feasibility of fighting global warming, you'll be swept up by a big wave from the rising oceans. And we will all ask :"Does it even matter he was here?"

If you have a better unit of measure for comparison, we'll all be glad to hear it.

Also, I applaud the author for his image of moving New York inland to flee the rising tide. This might only be a fantasy if not for the evacuation of New Orleans, a sizeable portion of whichhas not returned. Call it a dry run. (duck)