On the day after hopes for a mandatory U.S. cap on greenhouse gases evaporated, a new report  by the World Resources Institute delivers a timely message: Using existing federal, state, and local programs and rules could deliver deep reductions in U.S. carbon emissions. It won't be easy, the group says, requiring "go-getter" ambition and enforcement, but approaching President Barack Obama's stated goal of reducing climate pollution by 17% below 2005 levels by 2020 is "technically feasible."
A rainbow of federal and state rules, standards, and programs could deliver up to 2.5 billion metric tons of cuts in greenhouse gas pollution per year, the report said. Power plants could yield the biggest cuts. Under a regime using the Clean Air Act that the Obama Administration has already begun  to roll out, the rules could cut as much as 800 million metric tons of emissions annually by 2030. Efficiency standards for cars, light trucks, and most SUVs, also coming from the Environmental Protection Agency , could yield another 300 or so million metric tons by then.
Some big cuts could come with relatively little effort.
Using existing rules, just a "lackluster" effort to cut HFCs , which are mostly unregulated coolants found in cars and refrigerators, could yield a whopping 240 million metric tons of reduced emissions by 2030. Aggressive enforcement of existing standards or regulations on refineries, factories, and aircraft would have a meaningful, though smaller, impact, the report notes.
State action counts, the report says. Without aggressive enforcement of state rules, standards, or pacts—roughly half the states are members of regional cap-and-trade initiatives, for example—the United States could achieve only a 12% cut below 2005 levels by 2020. With aggressive state action, the savings grows to 17%.
The authors, who hadn't planned to release the report on the day after the climate bill collapsed, say that existing rules and standards aren't sufficient. If Congress doesn't create a declining cap on emissions, they warn, the on-the-books rules can only go so far. From a Q&A  with them:
With all the reductions you found that can be achieved by federal and state legislation, is a federal cap on emissions still necessary? Yes. The bottom line is that we need legislation. As the analysis shows, only legislation can get us the needed emissions reductions. Only legislation can lay out a long-term road map, create certainty, and drive investment in clean energy jobs. The tools we currently have at our disposal can get us significant and important emissions reductions and need to be preserved. For us, the takeaway is not "either or" but rather "both and." We need to both preserve the existing tools and enact legislation.