Weitzman argues — and I agree — that this risk of catastrophe, rather than the details of cost-benefit calculations, makes the most powerful case for strong climate policy. Current projections of global warming in the absence of action are just too close to the kinds of numbers associated with doomsday scenarios. It would be irresponsible — it’s tempting to say criminally irresponsible — not to step back from what could all too easily turn out to be the edge of a cliff.
...So what I end up with is basically Martin Weitzman’s argument: it’s the nonnegligible probability of utter disaster that should dominate our policy analysis. And that argues for aggressive moves to curb emissions, soon."
Link to the NYT article.