london • A green goldrush is under way in the hunt for low carbon technologies to beat global warming.

Billions of dollars are involved, from trading in rights to emit greenhouse gases to funds supporting green technologies and backers of big projects like wind and solar farms. The stakes are high - the planet's climate. Barely a year ago it was mainly specialist carbon funds and hedge funds, some of which take on high risks in hope of big returns, that were prepared to bet on technologies to cut emissions of greenhouse gases.

Now the big money players are muscling in. "This year the blue chip investors are moving in - the big banks and the pension funds with a lot of money," Anthony Hobley of green investment fund Climate Change Capital told Reuters.

Climate Change Capital has nearly $1 bn under management, tycoon Richard Branson has pledged $3bn for biodiesel research and blue riband investment bank Morgan Stanley has announced $3bn for carbon-related activities.

Pedro Moura Costa, founder of EcoSecurities carbon credit trading company, said there were now some six listed carbon trading funds, with market capitalisation of over $1.89bn, whereas two years ago none were listed. "If you pick a winner in the right technology in the search for a low carbon economy you are talking about potentially billions. It is really the holy grail," he said.

This week environment ministers from more than 70 countries debated in Nairobi how to extend the Kyoto Protocol on global warming beyond 2012.

Kyoto sets emissions cuts targets for 35 countries, and a deal, expected in 2009 or 2010, would further boost demand for renewable energy and rights to emit greenhouse gases, called carbon credits.

Funds which set up in 1997, as Kyoto was being negotiated, got a shot in the arm in 2002 when Britain set up its own carbon trading scheme. They received a major boost in early 2005 when Kyoto came into force and the European Union's Emissions Trading Scheme launched.