Does the Paris agreement open the door to geoengineering?

The international climate agreement just concluded in Paris establishes an aspirational goal of limiting the rise in global temperatures to 1.5 degrees Centigrade above pre-industrial levels, with a firmer goal of a temperature ceiling “well below” 2 degrees.

But can those goals be achieved by limiting future greenhouse gas emissions alone? According to law professor Dan Farber, co-director of Berkeley’s Center for Law, Energy, and the Environment, the 1.5-degree goal “almost certainly would require geoengineering, such as injecting aerosols into the stratosphere or solar mirrors.” Optimistically, he says, “the goal is achievable — but only with immediate, rigorous emissions reductions combined with new technologies to remove CO2 from the atmosphere.”

Maybe new energy technologies “will be able to get us the kinds of cuts we need quickly and cheaply enough to attain the goals,” writes Farber (who is not a particular fan of geoengineering). “Otherwise, though, if we are serious about those temperature targets, we may end up with little other choice than layering some geoengineering efforts on top of aggressive emission cuts.”

Read Dan Farber’s post on the Berkeley Blog.