On Monday, Nancy Pelosi told reporters that she has the votes to pass a carbon cap-and-trade bill through the House right now, but won't force the issue just yet: "I'm not sure this year, because I don’t know if we’ll be ready. We won’t go before we’re ready." What's that supposed to mean? As Keith Johnson suggests, part of the rationale for taking it slow seems to be that Pelosi wants to avoid making the same mistakes Europe made with its cap-and-trade regime (as when it initially gave away too many pollution credits), and figures it's better to do it right than do it quickly.

That's a reasonable thought—after all, even if Congress rushes to enact an economy-wide cap-and-trade bill by early 2010, one that, say, aims to cut U.S. emissions below 1990 levels by 2020, many experts think it will still take a few years for the new system to get fully up and running. In the meantime, then, Congress can address climate change (and begin curbing emissions) with a variety of short-term measures, such as bolstering the national grid to make it easier to harness wind and solar power, or by getting started on large-scale efficiency projects—things that Obama's seriously considering. Crucially, most of those measures will make it much cheaper and easier for businesses and households to make cuts under a nationwide emissions cap when it does finally take effect.

That still leaves a snag, though. Most climate campaigners were hoping that the world could agree to a successor treaty to the Kyoto Protocol by the end of 2009, in talks at Copenhagen. But it would be murderously difficult for the Obama administration to strike a deal abroad without having a commitment for emissions-reductions already in place at home—if we haven't passed a hard cap, China and India won't likely adopt one, either. But, conversely, it would also be nearly impossible to get a cap-and-trade bill passed through Congress if Obama's already agreed to a treaty at Copenhagen—especially one that doesn't include firm targets for China and India. So if Congress doesn't pass a bill by the end of 2009, that may push international negotiations back, as well. You can read all about the delicate diplomatic dance involved in this Greenwire piece.

Suffice to say, timing and sequencing are going to be nightmarish questions to resolve. If there's one bright spot, though, it's that the very deep recession plaguing the planet has caused emissions to plummet—even in China, as this stunning graph dredged up by Andy Revkin illustrates:

That doesn't make global warming any less pressing (after all, carbon concentrations in the atmosphere are still growing, even if emissions are slowing or shrinking), but it will give Obama—and the world—a tiny bit breathing room to try and hash out a policy response.

--Bradford Plumer