The Bush years—a seemingly endless era in which those concerned about the planet’s fate found themselves arguing with a table, to appropriate the words of a silver-tongued Massachusetts congressman—aren’t typically remembered for good efforts to combat global warming.

But a new report by Environment America—"America on the Move"—contends those lost years, thanks to states (not the Bush administration), may actually prove themselves a critical period in our national efforts to lower carbon pollution. The report estimates that states like California, Massachusetts, Hawaii, and many others initiated programs during those years that will lead to a reduction of more than 500 million tons of global warming pollution by 2020.

The projected amount, approximately 7 percent of total domestic emissions in 2007, is no small thing, roughly equivalent to the collective annual emissions of more than 100 million cars.