US plan to cut greenhouse gases by 70 per cent signals change of heart on climate change

Key measures to tackle global warming have been approved in the US Congress, signalling the first crack in the granite face that the Bush administration has set against cutting the pollution that causes climate change.

Both the Senate and the House of Representatives last week advanced Bills that would drastically reduce US carbon dioxide and other greenhouse gases, raise fuel economy in US vehicles and set radical targets for increasing renewable energy production.

US government representatives last week suggested for the first time that they may agree to binding international targets for reducing emissions of greenhouse gases. On Wednesday the Senate's Environment and Public Works Committee voted 11-8 to cut emissions by about 70 per cent by 2050. This would make the US a world leader in tackling global warming.

The Bill put forward by the former Democratic vice-presidential candidate Joseph Lieberman and Republican Senator John Warner would limit businesses' gas emissions, but allow those companies that exceeded them to buy allowances from those that overshot targets.

The second Bill passed by the House of Representatives by a 235-181 vote on Thursday would force the country's cars, small trucks and SUVs to achieve an average of 35 miles per gallon by 2020, cutting greenhouse gas emissions by 192 million tons a year, equivalent to taking 28 million vehicles off the roads.

The Bill would also require electricity utilities to produce 15 per cent of their power from renewable sources by 2020, cutting annual emissions by another 180 tons. By 2022, cars would also have to be using 36 million gallons of biofuels, and nearly half of these must be second-generation fuels, derived from wood, weed and other crops that do not compete with food supplies. The Bill will also ban conventional light bulbs.

Although President Bush has vowed to fight the Bills, both of the front-running Democratic contenders for the White House, Hillary Clinton and Barack Obama, have signalled that they intend to embrace the climate change agenda, suggesting Capitol Hill is already looking ahead to life after the president's departure.

The measures would be financed by repealing a $13bn (6.4bn) tax break for big oil companies.