I'm attending a water law conference in San Diego this week. Today's presentation included a discussion of attempts to limit pollution in the Chesapeake Bay. The presenter said that nitrogen and phosphorus pollution is likely to be set at certain maximum levels pretty soon, and following that, anyone who wants to do something that adds pollutants will have to find offsetting reductions. He speculated that a cap-and-trade market might even emerge.
I think this is still more evidence that there's nothing innately wrong with offsets and trades in greenhouse gases, and that the only real question is whether the programs are done well or done poorly.
One other piece of info that was climate related: another presenter discussed cost-benefit analyses in federal environmental regulations. I asked whether international effects were considered. He said not as a usual matter, but climate change is forcing them to think about it. They now give two different prices for the cost effect of increased greenhouse gases: one price is if they assume the US is all that counts, and another if they assume that we live on planet Earth. We'll see which one ultimately wins out.