IPCC Global Warming Projections (as of 2/2007)

Climate model estimates of twenty-first century global warming are still fuzzy to a factor of three--plus the uncertainty about what policies will be, and what the effects of policies on emissions will be. But they are a lot less fuzzy than they were a decade ago.

The prospect of a world that is five degrees warmer in a century is unsettling. More unsettling is what happens after 2100.

Comments

[Will]

Professor, do you know of anyone that can explain the fundamental differences between economic forecasts and climate forecasts. If someone told me they looked at the the last century of income data and they had projections a century and a half ahead with such small error bounds, I'd say they're crazy.

I know climate folks are working with more deterministic systems, but these forecast error bounds just don't sit well with me.