Los Angeles (AP): A day before he was to welcome hundreds of high-ranking officials for a summit on greenhouse gas emissions, Governor Arnold Schwarzenegger raised the environmental stakes in California.

Schwarzenegger signed an executive order committing the US state to obtaining a third of its electricity from renewable sources by 2020. California previously had committed to producing 20 per cent of its power from renewables such as wind and solar by 2010.

"I am proposing we set the most aggressive target in the nation for renewable energy," Schwarzenegger said on Monday. The state legislature still must pass the goal into law.

The move came on the eve of the Governors' Global Climate Summit, bringing together scientists, environmentalists and government and industry officials for a two-day meeting.

The conference, which begins Tuesday in Beverly Hills, is an attempt by the Republican governor to influence a UN gathering in Poland next month. Schwarzenegger has said he wants the summit to inform negotiations over a new global climate treaty, which the UN hopes to finish by December 2009.

The UN's Intergovernmental Panel on Climate Change has said temperatures worldwide could increase between 4 degrees and 11 degrees Fahrenheit by 2100 unless nations reduce their emissions.

Division remains over how much countries should be required to cut, especially as the world grapples with a financial crisis. Italy and several Eastern European nations have argued that the costs of cutting emissions are too much for their industries to bear during the economic downturn.