Over on Dot Earth, Andy Revkin has an interesting Q&A with Joe Romm pivoting off Romm’s letter to James Hansen. Joe says this about cap-and-trade:

I don’t see that as the first strategy anymore, as I said in my Nature Online article. The latest science suggests that national and global climate policy is seriously misdirected. We must aim at achieving average annual carbon dioxide emissions of less than 5 GtC [5 billion metric tons of carbon] this century or risk the catastrophe of reaching atmospheric concentrations of 1,000 p.p.m.

A carbon price set by a cap-and-trade system is a useful component of a longer-term climate strategy. Implementing such a system, however, is secondary to adopting a national and global strategy to stop building new traditional coal-fired plants while starting to deploy existing and near-term low-carbon technologies as fast as is humanly possible.

So we need to stop new coal now. Ramp up spending on technology deployment now. Shift state regulations to put energy efficiency on an at least an equal footing as supply. Meanwhile, we enact a hard cap without many offsets.

Worth reading the whole thing.