I'm no expert on environmental policy and so I have few means of evaulating Sen, McCain's environmental policy proposals, including the cap-n-trade schema he outlined today. As you might imagine, the organized Democratic left is throwing everything at the wall, and that's not particularly helpful for those of us who like our policy evalulations less hyperbolic. So here's the take of David Roberts of the excellent environentalist blog GristMill:

It comes as no surprise that the focus is on a cap-and-trade program, something McCain has supported for five years. In fact, there is virtually no mention of any emission reduction policies outside of cap-and-trade -- no efficiency or fuel economy mandates, no electrical utility decoupling, no mention of public transit. McCain obviously retains his conservative allergy to regulation and public spending. There is some discussion of funding research and incentivizing market deployment of new technology, but the details are tantalizingly vague. Perhaps they'll be fleshed out in the energy speech.

One area where McCain deserves big kudos: He devotes a good chunk of his speech and his policy plan to adaptation, something that's been too far under the radar in climate discussions. Substantial impacts from climate change are inevitable, and it's high time the federal gov't got serious about coordinating and funding local efforts to prepare.

As for the cap-and-trade program itself, McCain's basic targets and mechanisms are roughly in line with what others have proposed. He would aim for 1990 emission levels by 2020, and 60% below 1990 levels by 2050. That long-term target falls short of the "80% by 2050" recommended by the IPCC and beloved of climate activists, but the short-term target is roughly in line with what's offered in the Lieberman-Warner bill and Barack Obama's plan.

It's the cost-control measures that are sure to be controversial. McCain does not include the much-maligned "safety valve," whereby carbon prices cannot exceed a pre-set cap. He does, however, propose to allow unlimited use of domestic and international carbon offsets for compliance with the cap, at least initially. He would also give away rather than auction a substantial portion of the original pollution permits. (The level of compliance permitted via offsets and the number of permits given away will both decline over time, on a schedule determined by the Climate Change Credit Corporation, the public-private agency McCain proposes to oversee the program.)

Read the whole thing. He concludes that "it's better than expected, somewhat short of Lieberman-Warner, and far short of what Obama has proposed."