BARACK OBAMA is certainly talking the talk on climate change - promising to put the fight against global warming at the heart of his second term. What's more surprising is that the US - historically, the world's biggest emitter - actually seems to be walking the walk. It is on track to meet Obama's 2009 pledge to cut US emissions by 17 per cent, from 2005 levels, by 2020. The target could even be exceeded, which may give a boost to the long-stalled international climate talks.
There's no realistic possibility of passing new laws to curb US greenhouse gas emissions - Republican control of the House of Representatives will see to that. So some pundits were scratching their heads at Obama's climate pledge in last week's inaugural address. But independent yses paint an upbeat picture of the progress he can make simply by using existing laws.
After the gloom that followed the failure, in Obama's first term, to pass a national cap-and-trade scheme to cut emissions, the new mood of optimi may seem surprising. Yet it is backed by hard numbers, laid out in a report released last October by Resources for the Future (RFF), a think tank based in Washington DC.
The group totted up emissions reductions likely to result from action taken by states and cities, and cuts that will occur through market forces as a glut of cheap natural gas encourages power utilities to burn gas instead of coal - which emits far more for the same amount of energy generated. Together, these get about a third of the way to Obama's pledge.
But the biggest contribution comes from regulations under the Clean Air Act, including vehicle fuel economy standards that are already in place. Controls on emissions from power plants that are expected from the US Environmental Protection Agency make up the rest (see diagram). Given all this, RFF estimates that the US could cut emissions by 16.3 per cent by 2020.
"The US had been doing more than we're given credit for," says Matt Woerman, one of the report's authors. "As an American citizen, I'm pleasantly surprised."
"The 2020 target does seem to be in reach," agrees Kevin Kennedy, who heads the US climate change initiative at World Resources Institute, also in Washington DC. The think tank is expected to draw similar conclusions in a report due for release in early February.
According to Woerman, about two-thirds of the cuts outlined in the RFF report are already "baked-in". And emissions could be pushed down further still if the EPA is aggressive in regulating existing US power plants.
The RFF report assumed that the EPA would demand modest efficiency improvements for each type of plant. But the agency could get stronger cuts by setting a combined and more ambitious target for coal and gas-fired plants, and leave it to utilities and states to decide how to get there.
That would provide fresh incentives for power companies to ditch coal for natural gas. It could even bring in cap-and-trade by the back door, if companies and states decide schemes like the Regional Greenhouse Gas Initiative, launched by a coalition of north-east US states, could help make the cuts.
According to an ysis from the Natural Resources Defense Council (NRDC), released in December, more aggressive policies like these could cut emissions from fossil fuel plants by 26 per cent, from 2005 levels, by 2020 - equivalent to an additional 10 per cent shaved off total US emissions.
Other options open to Obama include an aggressive phase-out of hydrofluorocarbons - refrigerants that are potent greenhouse gases - and plugging methane leaks (see "Fixing America's gas leak").
No one has yet calculated the amount by which the US could exceed Obama's pledge, but Woerman is optimistic. "I think we can definitely blow past the target," he says. "Maybe we could get to 25 per cent."
Numbers like that would give Obama new authority in talks with other major polluters such as China, which have been reluctant to sign up for emissions cuts while the US seemed to drag its feet. "The US will have much more credibility and influence in the next international climate negotiations if it shows, by 2014 and 2015, that it is making good on the president's pledge," says David Doniger, climate policy director with the NRDC.