Voters in Indiana last week asked Barack Obama what his highest priorities would be in his "first 1,000 days in office". Ahead of universal healthcare and ending the Iraq war, the first item on Mr Obama's list was comprehensive energy reform. Observers of the increasingly commuter-focused presidential debate in the US could be forgiven for thinking that the pain of high petrol prices has driven the issue of global warming off the political agenda. But they would be wrong. Both Mr Obama and John McCain are promising to implement radical cap-and-trade plans that would curb US carbon emissions - in Mr McCain's case a 60 per cent cut below 1990 levels by 2050, in Mr Obama's an 80 per cent decline. Given the economic climate, neither candidate finds much profit in drawing attention to their plans - and when they do it is usually in the context of achieving "energy independence" rather than tackling global warming. Yet neither has given in to the temptation to water them down. "I hate to be fair to the Obama campaign but it is remarkable that we have two presidential candidates who are proposing mandatory plans to reduce -America's carbon emissions," says Douglas Holtz-Eakin, Mr McCain's senior economic policy adviser. That is where the similarity ends. The difference between Mr McCain's plan, which would initially -allocate tradeable carbon permits for free, and Mr Obama's, which would start with a 100 per cent auction of permits, is large. The McCain camp describes its opponent's plan as imposing too steep a burden on businesses too quickly without easing the transition costs. The Obama campaign describes Mr McCain's plan as a recipe for "corporate welfare" since it would incentivise Washington's corporate lobbyists to push for more free permits to be awarded to their sectors. "The lesson from the European experience is that you don't want to give away -permits - you should move immediately to a marketdetermined price for carbon," says Jason Furman, Mr Obama's economic policy director. "You should aim for as much predictability and reliability as possible in terms of the number of -permits. And you should ensure the carbon caps are as comprehensive as possible. McCain meets none of these criteria." Mr Obama's plan promises to allocate $15bn (