Even if Manzi is right that the costs [from global warming] are manageable into 2100 -- a century, after all, is a long time for a human, but not for the atmosphere -- what does that do to our descendants who have to deal with a scorching planet between 2100 and 2200? And then into 2300, and then 2400?
I think Manzi's answer is that technology will save us by then. And maybe he's right. But maybe he's not. And if he's not, then we've let the problem become unimaginably bad for our descendants. If you bet on technology and you're wrong, it's not like we've got another of these planets waiting in the back somewhere.