First things first: We love Barack Obama here in Britain, maybe almost as much as you do. Possibly there are disappointed Republican sympathizers in the U.K., but I haven’t met any, and relief at the retreat of Sarah Palin as political force is almost palpable. Across much of Northern Europe we liked Obama so much that it began to make you guys suspicious and we had to back off — like parents being too enthusiastic about a nice new boyfriend.

As Iain Martin put it in the Telegraph, “[T]his is about more than race. Many Britons will simply be pleased that they can, at last, like America again, untroubled by thoughts of George W. Bush.” A poll for the Times suggests that Obama’s popularity rating in the U.K. is higher than for any leader — British or American — in the last six years. Two-thirds of us think that our prime minister, Gordon Brown, should forge closer links with Obama — double the proportion who felt the same about Bush.

This is part of a wave of pro-Americanism in the media here. Beyond the endless fascination with the U.S. election — a year of it, during which elections in other countries ’round the world, including Russia, went virtually unnoticed — there have been series about America on TV, from quintessential Englishman Stephen Fry (where he tours the U.S. just generally lovin’ it) and historian Simon Schama (who has somehow managed to reframe the American dream for us).

So now the implausible has actually happened, and the euphoria is beginning to give way to more reflective debate on what it all means. By and large, commentators like Obama’s eco-rhetoric. The mention in his acceptance speech of “planet in peril” as an equal partner in a new axis of evil facing the U.S. is a good start. And there are plenty of wish lists from green groups should Obama be short of ideas, with Friends of the Earth U.K., for example, calling on him to kickstart a green revolution.

But everyone here also knows that Obama will inherit a chalice of crap of the sort last seen when Franklin D. Roosevelt came into office, so they’re trying to manage their expectations.

The more sober environmentalists are also yet to be convinced Obama has a radical enough package. Writing in the Telegraph, Charles Clover points out that Obama “would not cut U.S. emissions as much as Al Gore pledged to do under the Kyoto treaty in 1997” and that his “target for stabilizing America’s emissions at 1990 levels by 2020 amounts to no more than meeting the pledge which George Bush, Sr. signed at the Rio Earth Summit in 1992.” He also notes that the tests of Obama’s commitment will come thick and fast — perhaps the greatest being the speed with which Obama can respond to the Polish round of climate-change negotiations in a few weeks’ time — and wonders if he is ready to wade in at the necessary speed.

Others are interested in how Obama’s going to use those cheap loans to the car giants, with Grist’s Kate Sheppard arguing in the Guardian that he should attach strict fuel-economy requirements as part of a “tough love” package. This piece generated quite a debate, with one respondent longing to see Arnold Schwarzenegger, as Obama’s energy guru, take on our own Jeremy Clarkson (a BBC-sponsored, petrol-head, climate-denying, shock-jock type), perhaps in combat. Now that I’d pay to see.

Obama makes our current crop of leaders look deeply unexciting. This is less of a problem for Gordon, who was so far into the brown that things could only get better, and they duly have. Conservative Party leader David Cameron is the real loser — he was supposed to be the bright, young thing with a new agenda, but first he had nothing distinctive to say about the financial crisis, and now Obama makes him look both establishment and lightweight at the same time. Whether this will cause him to dust off his much-vaunted environmental credentials remains to be seen.

Meanwhile, Brown has been keen to position himself somewhere near the vanguard with Obama on a Green New Deal to use investment in the environment to reboot the economy. Maybe this is the start of a beautiful friendship, but with Obama offering a much more substantial investment package in green technology than we can dream of, there’s concern from the U.K. Environmental Industries Commission that we’ll be left behind in the race for green jobs. Frankly, given the urgency of the challenges, and the inevitable slowness of regulatory responses, a bout of transatlantic competition for the green economy sounds thoroughly welcome.

What Obama brings to the party, perhaps above all, is a sense that we are now on the same page in terms of the scale of the challenge, the need to motivate people, and the way to frame the issue if we are to be successful. Though the argument about climate change may have yet to be fully won in the U.S., the real communications challenge — of getting people to feel positive about the massive changes that lie ahead — is just beginning. In that task, someone with Obama’s power to inspire and his compelling seriousness will be a huge asset this side of the Atlantic too. If he can convince us we’ll make some money out of it along the way, so much the better.