What will Barack Obama be remembered for from his time as US President? Extricating America from Iraq? Preventing Pakistan from dissolving into nuclear-armed chaos? Dealing with the rumblings from Iran? Rebuilding the US economy? Or perhaps failing to do all, or any of those? Well, they are possibilities, every one. But here is one more which won't be on the tip of your tongue, I'll bet, but which could be at the heart of his most lasting legacy: building the smart grid.
The smart grid is a national electricity distribution grid which is as light and mobile and responsive as the internet, working from consumer to supplier as well as the other way round. Got more charge in your electric car than you need? Sell it back to the distributor through the smart grid, instantly. Got your tumble-drier working on a very hot day? Have the smart grid automatically turn off the drier's heating element for you.
The Americans do technology better than anyone, and the idea of the smart grid is at the very heart of the latest US techie thinking on energy-saving and low-carbon power systems. Bringing in a low-carbon economy is very near the top of Mr Obama's list of priorities. It was bottom of the priority list of George W Bush, the oilman son of an oilman father, surrounded by oilmen cronies, and the shift Mr Obama so strongly symbolises will be felt here as much as anywhere.
There is the real possibility now that the US under Mr Obama will charge off into a low-carbon future with all the fantastic energy and scientific inventiveness that built the atom bomb first and put a man on the Moon first. The President-elect has indicated as much: he can tell you what a smart grid is.
This matters for the world just as much as for Uncle Sam, for despite everybody's hopes, global agreement on a new round of carbon emissions reductions may be impossible to achieve when the world community meets to discuss the future of the Kyoto Protocol on climate change in Copenhagen in December 2009. The arguments about burden-sharing will be too intractable ("We won't do this unless you do that").
But if America is seen by others – China above all – in a quite different way, as winning the race to build the first low-carbon economy, as a business opportunity rather than a burden, others will want to follow suit. It doesn't all have to be done through treaties. The world's effort at countering global warming was held back for eight critical years by George W Bush. Barack Obama's America might yet lead the way forward, even if it is not quite in the way people are currently expecting.
A twitcher writes...
Hot news! Remember The Independent's house sparrow prize? Eight years ago, we offered a £5,000 reward to anyone who could explain (scientifically) the sparrow's disappearance from Britain's towns and cities – a tempting offer which has never been claimed. In fact, there has never been a serious entry. Well, now we have received one and the judgement will be up to our referees, the Royal Society for the Protection of Birds, the British Trust for Ornithology, and Dr Denis Summers-Smith, the world's leading expert on sparrows. Watch this space.