Arnold Schwarzenegger, the governor of California, joined Tony Blair in Downing Street yesterday to appeal for an international effort to fight the threat of global warming.

In what was the Prime Minister's final press conference before he stands down to make way for Gordon Brown today, Mr Schwarzenegger, better known for his role in the Terminator films, applauded Mr Blair's efforts to persuade the international community to take global warming seriously. He even suggested that the outgoing Prime Minister be appointed international envoy for the environment.

Mr Blair and Mr Schwarzenegger, who later attended a round table discussion with business leaders, emphasised the importance of getting an international agreement to reduce emissions of greenhouse gases once the targets set in the Kyoto Protocol expire in 2012.

In particular, they urged George W Bush to take a lead in the global efforts. Mr Blair indicated that the US President would not sign up to any agreement which did not include China and India but Mr Schwarzenegger appealed to Mr Bush to sign up without them.

He said: "It was not good enough for the US to demand action on climate change from developing countries, when it produced 25% of the world's carbon emissions with just 5% of its population. The idea of continuing to say that China should come in otherwise I'm not going to', that doesn't work. We have to show leadership."

Both Mr Blair and Mr Schwarzenegger made clear they regard technological innovation as a key to solving the problem of global warming through more efficient energy production, cleaner cars and planes and emerging techniques like carbon sequestration to prevent the release of greenhouse gases into the atmosphere. Such was their potential the Californian governor hailed them as the source of the new gold rush.

Commenting on today's meeting between Mr Blair and Mr Schwarzenegger, Dr Steve Howard, chief executive officer of non-governmental organisation The Climate Group, said: "The scale and urgency of the climate change problem facing us calls for unprecedented collaboration.

"The companies here today are already leading the way in reducing their own carbon footprints and are now turning their attention towards making it easier, cheaper and more appealing for consumers to play their part in the solution."

Joking before he said goodbye to the assembled press corps, Mr Blair borrowed a line from one of his Terminator films to say farewell: "My press officer said to me: Whatever else you do this morning, don't say I'll be back'."