It was always likely that the Bali climate change conference would cobble together some kind of deal. Sure enough, in the early hours of yesterday morning after tears, tantrums, boos and recriminations, a “Bali road map” was agreed setting out what the United Nations described as a clear agenda for two years of talks aimed at negotiating a successor to the Kyoto framework. “This is a historic breakthrough and a huge step forward,” said Hilary Benn, environment secretary. “For the first time ever all the world’s nations have agreed to negotiate on a deal to tackle dangerous climate change concluding in 2009.”

It is easy to dismiss such claims as hyperbole and the Bali deal as yet another fudge from governments, particularly the US government, unwilling to face up to the hard decisions on global warming. The price of getting the United States to sign up was the removal of hard numbers from the road map. Friends of the Earth dismissed it as a “weak outcome” and accused rich countries of letting the developing world down.

Yet Bali was always going to be a holding operation. There was pressure for specific targets to be included in the text. The European Union wanted a commitment to emissions reductions by advanced countries of 25% to 40% by 2020, as well as references to a peak in global emissions over the next 10 to 15 years and a halving by 2050. It is reasonable to argue, however, as America did, that such targets should emerge during the negotiations of the next two years, not be imposed at the outset. America also made important concessions.

Al Gore said it outright in Bali but the unspoken message of yesterday’s deal is that things will change over the next two years, most importantly in the White House. Attitudes are moving in America. Politically this has been led at state level by the likes of Arnold Schwarzenegger and at city level by the mayors of most US cities. George W Bush has looked increasingly out of step with public opinion. Next November’s presidential election should see a new era in the White House on climate policy. The Democratic frontrunners, Hillary Clinton and Barack Obama, are both seemingly green. Mr Obama wants to introduce an economy-wide “cap-and-trade” programme to cut US greenhouse gas emissions and to invest heavily in energy efficiency.

Mrs Clinton, running a “carbon neutral” campaign, has a similar plan for cutting emissions but also wants a windfall tax on oil companies to be invested in an energy fund to provide one-fifth of US electricity from renewables by 2020. On the Republican side, Senator John McCain was the first to highlight global warming and, while he has little chance of securing the nomination, his rivals have jumped on the band-wagon. Oil at $90 a barrel and a determination to reduce dependence on the Middle East are enough to convince even the sceptics.

Political change is important but so is technology. Developing countries suffer from the effects of climate change but often cannot afford the equipment needed to limit their own pollution and greenhouse gas emissions. Even China, growing at a breakneck pace, is still building dirty coal-fired power stations rather than using the clean coal technology available in the West. One significant breakthrough in Bali was an agreement to step up the rate of technology transfer and provide the private sector with more incentives to give poor countries access to the latest innovations.

Bali should not be dismissed. It is not long since Tony Blair said there would never be a successor deal to Kyoto. Now a deal looks distinctly possible, if only after some hard negotiations over the next two years. And it will have America, China and India on board. It is easy to be gloomy but political will and technological change are powerful allies. If these bleary-eyed declarations are followed up with action, there is every reason to be hopeful.