twenty years of protracted diplomatic talk and laborious scientific study have so far failed to move the needle on emission rates.

A similarly realistic view of the longer term is that the world is very unlikely to zero out its net emissions by 2075, let alone by 2050, and so society will largely respond by adapting. I’m in that latter camp, and I have more than a few informed camp mates.

Reality thus presses in from both ends. The sheer scale, cost, and technical inertia of carbon-dependent activities make it impossible to eliminate all of these uses in just a few decades.