I’m a bit late on this (that’s my new thing), but things just keep getting bigger and better when it comes to climate policy. Arizona, California, New Mexico, Oregon, and Washington are joining forces to reduce emissions. Kudos to all five governors who pledged that:

…within six months they will set a regional target for lower emissions. A year after that, they pledged, they will devise a regional cap-and-trade system, which would let companies that can’t meet their emission reduction targets buy credits from those that reduce emissions more than required.

There’s even icing on the cake: British Columbia is likely to join in, which makes sense given that North America’s energy grid is pretty well integrated across national boundaries.

It strikes me that the combined commitment is good for at least two reasons: 1) It pressures each of the member states to take their goals seriously; 2) The sheer size creates an ever more effective market for reducing emissions, one that is big enough to force meaningful action from national governments. In fact, the combined population of the five states and BC is roughly that of Italy, France, or the United Kingdom (or, if you prefer, as large as Canada, Australia, and New Zealand combined).