. When legislators attempted to expand the approach to address CO2 emissions "it ran into gale-force opposition from the oil industry, conservative groups that portrayed it as an economy-killing tax and lawmakers terrified that it would become a bonanza for Wall Street traders and Enron-style manipulators."
Today I read a report on the Regional Greenhouse Gas Initiative, an effort carried out by 10 Northeast and Mid-Atlantic states. The focus has been on reducing CO2 emissions, and the group is seemingly reporting good results. You can judge for yourself in an article summarizing the results.
Now, of course, CO2 emissions remain a controversy for some, and a largely settled, if still evolving, piece of science for many others. But I did find the results interesting. Perhaps you will, too.