To clarify: a carbon wedgie is what Mallorcan tennis great Rafael Nadal suffers when he practices too long in the hot Mediterranean sun and his shorts get sweaty and creep up and in.
A carbon wedge is what you get when you want to avoid emitting 1 gigaton of carbon per year that you otherwise would emit 50 years from now if the world follows a business as usual path.
The wedges model, invented seven years ago by Robert Socolow and Stephen W. Pacala of Princeton University has been far and away the most influential and popular tool used in discussions of long-term climate policy. Besides providing handy reference points for back-of-the-envelope calculations, it has spun off a nice board game suitable for introducing children and grandchildren to all the fun of preventing global extinction.
Responding to what apparently was an inaccurate blog post suggesting Socolow now regretted his invention, the Princeton energy expert has published an article reaffirming his faith in the wedges tool and updating it. Because of delays in introducing effective climate policies worldwide, Socolow says it would now take nine rather seven carbon mitigation wedges to keep the human race from emitting more carbon 50 years from now than it emits today.
Socolow takes the occasion to deliver some thoughts about mitigation of climate acrimony. He says he wishes advocates of strong action had conceded that news about climate change is unwelcome, that today's climate science is incomplete, and that any suggested "solution" carries some risk. On the first point, for example, he seems to think that action advocates have suggested that if we just go green, we'll all be living once again in the best of all possible worlds.
Those considering Socolow's points—and they're well worth considering—may differ about the details. But everybody will welcome the thrust of what he’s aiming at: how to get discussion of climate science and climate policy onto a better plain, so that some people don't get a kind of carbon wedgie every time they hear talk of human-induced climate change.