For America's League of Conservation Voters, it's like Christmas every day. The long night of the Bush administration is drawing to a close, and a new dawn is already heralded by birdsong and sweet-smelling air. Eight out of ten of its Senate endorsements won their seats (assuming Al Franken in Minnesota holds his razor-thin recount victory), while in the House 41 out of 54 LCV-endorsed candidates won their races. And then there is the new president. The league can barely contain its enthusiasm for Barack Obama - in a recent web advert it portrays him in superhero garb battling the moustachioed "special interests" of coal, oil and nuclear power.
Surely it's got to be downhill from here. But the signs so far are extraordinarily good. Obama's picks for his new administration have been almost universally welcomed by American greens. The former Iowa governor Tom Vilsack, Obama's choice for agriculture secretary, has a perfect 100 per cent score on the 2008 LCV scorecard - an unusual feat even for a progressive Democrat. Obama's energy pick, Steven Chu, is a Nobel Prize-winning professor of physics and a strong believer in clean energy, light years away from Bush's prolonged war on science. And the president-elect has even created a new post of "energy tsar", where Carol Browner (who headed the Environmental Protection Agency during Clinton's two terms) will have a broad brief to begin the decarbonisation of the US economy.
To call this a "green dream team" would not be putting it too strongly. But what about actual policies? With the fiscal crisis intensifying into an unemployment crisis (two million jobs lost so far) and threatening an era of prolonged depression, Obama has made it clear that everything has to be subsumed into the urgent task of rebooting the economy. Accordingly, all eyes were on the draft Obama-Biden stimulus package circulating on Capitol Hill earlier this month. The plan makes it clear that the US car industry will indeed be bailed out, not just to save jobs but to "ensure that the next generation of clean vehicles is built in the United States". Although most of the document deals with the nitty-gritty of tax credits, mortgage assistance and the like, a section on "Manufacturing and Green Jobs" restates the campaign-trail commitment to spend $150bn over ten years on clean-energy technologies, and commits to 25 per cent of electricity being generated from renewable sources by 2025.
But there is much, much more that needs to be done - and the danger is that a single-minded focus on the economy (even with the greenish-tinged stimulus package) will distract the new administration from other urgent tasks. The first of these has to be the creation of a US-wide "cap-and-trade" plan to limit carbon emissions across the American economy - something that Obama has repeatedly promised, but may run into problems delivering given the shakiness of the economy. "Special interests" provide jobs, too, after all, and existing lobbies always fight harder than fledgling ones. Recent EU experience is salutary - Europe's own cap-and-trade scheme has run into the sand because of industry lobbying, with the cement, car and coal industries using the credit crunch as a reason to demand - and win - a further round of free carbon giveaways. The European carbon cap is now so weak that the latest estimates suggest industry will be able to avoid any emissions cuts until 2017 simply by buying cheap overseas offsets.
Now the EU has dropped the ball on climate, America has to lead the way. After years of inaction, Obama really is our last hope. If the US gets serious about cutting its own emissions and speeding the transition to a clean-energy economy, then China too may feel impelled to move, breaking the international political deadlock. But the US has a long way to go - its own emissions have soared since Bush repudiated Kyoto back in 2001.
For its part, the US environmental movement is not short of demands. At the end of November, a coalition of 29 green NGOs published a 390-page document for the Obama transition team, requesting a 35 per cent domestic carbon emissions cut by 2020, better protection for the Arctic against oil drilling, policies to promote organic farming, a stronger focus on wildlife conservation and the restoration of science as the basis for environmental policymaking, as well as a whole host of other reforms. The problem will be balancing all these competing demands at a time when presidential attention is constantly demanded elsewhere - as the economy continues to slide and the war in Afghanistan intensifies, not to mention the crisis in Palestine.
But if even a small proportion of Obama's rhetoric is translated into concrete action, then a new era really is unfolding. George Bush will be history. It's a delicious prospect.