The US stance on global warming is changing, argues Jonathan Lash in the Green Room. But, he says, the international community needs patience still.
In the United States, we have let our climate policy develop at glacial speed; who says we don't have a sense of irony?
US progress on climate has been "glacial", says Jonathan Lash
In place of a sustained supporting role in the ongoing international climate change negotiations, the US has instead opted for a combination of modest bilateral and regional initiatives.
These have included the Asia-Pacific Partnership on Clean Development and Climate, the International Partnership for a Hydrogen Economy (IPHE), the Carbon Sequestration Leadership Forum (CSLF), and Methane to Markets.
While there is real potential for such initiatives to advance global technology and policy on emissions reductions, funding for these efforts has been modest, and political support tepid at best.
In some cases, such as that of hydrogen, the technology proposed is not expected to mature for 50 years - hardly in keeping with the science, which indicates that deep cuts will be needed over the coming few decades.
Other countries have made some important moves without the US.
The debate about climate science is, at last, drawing to a close; of course, it wasn't really a scientific debate at all
Europe has implemented a major emissions trading system (modelled, ironically, on the US system for capping and trading sulphur emissions) as well as making major strides in promoting renewable energy and energy efficiency.
China, despite its relative poverty, has stronger fuel-efficiency standards than the US and has enacted more demanding targets for renewable energy and efficiency.
Against this backdrop, complaints from US politicians that the world's richest country would find serious climate policy economically ruinous look dubious. Other countries are finding that new clean technology markets are creating important opportunities for growth and innovation; opportunities that US firms are often missing.
However, there are costs, both economic and political, to constraining emissions without the broader participation of the world's largest emitter and economy.
Finally though, some big shifts are taking place that may, many hope, transform the role of the US from laggard to leader.
We have much in common with many other large emitters, most notably coal-dependent China
First, the debate about climate science is, at last, drawing to a close; of course, it wasn't really a scientific debate at all.
The evidence continues to accumulate: the National Academy of Sciences and the Intergovernmental Panel on Climate Change (IPCC) are among the many bodies that have compiled endless evidence of human influence on the climate. The Stern report has made a compelling economic case for early action to reduce emissions.
Truth to tell, climate science has not been controversial anywhere except Washington DC for years.
The changes in Congress will, however, make a difference.
Oklahoma's Republican Senator James Inhofe's removal as chair of that body's environment committee means that his quixotic struggle against reality will no longer be at the centre of public debate.
His replacement by Barbara Boxer, the California Democrat, means that serious discussion of the issue will at least get an airing in the Senate.
Second, the new Congress looks to be much more serious about climate policy.
A range of proposals for federal climate legislation are circulating in both the House of Representatives and the Senate, some of which have real ambition.
New Senate environment chair Barbara Boxer promises changes
Hope should be tempered by realism; climate is not a party issue, and many Democrats have coal, oil and auto lobbies to placate.
And any climate legislation needs to get past a Bush-Cheney team that has shown no signs of contemplating compromise. But a raft of measures, including renewable energy promotion, greater spending on energy research and development, and proposals to increase oil security may be within reach at both the federal and state levels.
Small and beautiful
Finally, while federal policymakers have been largely ignoring climate, others have made important progress. The list of proactive businesses, state legislatures and even city governments taking real action grows longer almost by the day.
One thing that is not likely to shift immediately, however, is the US approach to international climate policy, most fundamentally because that remains the prerogative of the administration.
Also, the underlying approach to international agreements has not changed. Unlike, for instance, the EU, which will sign up to an international agreement and then go home to decide how to implement it, US participation in international policy depends on solid domestic policy already existing.
Hydrogen may be a promising technology but is far from mature
At its best, the US can be enormously influential, and the most important thing we can do is lead by example.
We have much in common with many other large emitters, most notably coal-dependent China, which is famously erecting a new large power plant every week. Adopting technologies such as renewable energy or coal gasification for carbon capture and storage in our own country will do more to help China do the same than a hundred Asia-Pacific Partnerships.
This means that our international partners will find that their patience is still needed.
The EU and Japan have leant over backwards to ensure that the door is left ostentatiously ajar for US engagement. The challenge for the US now is to demonstrate that, even if it follows its own counsel in committing to policy, it is at least pulling its weight.
Our international friends, we thank you for your patience.
Jonathan Lash is president of the World Resources Institute in Washington DC
The Green Room is a series of opinion articles on environmental issues running weekly on the BBC News website