The global economic downturn and the crisis in the US financial markets offers the chance for investment in green energy, former US vice-president Al Gore said Thursday.

Central banks have thrown billions of dollars at the global credit storm, which has seen stock markets plunge and scalped big banks exposed to the ongoing effects of last year's collapse of the US sub-prime mortgage market.

Speaking via satellite-link at the launch of Live Earth India concert, where proceeds will go to solar energy projects, the environmental campaigner said the world was at a turning point.

Asked by AFP whether the financial crisis would mean less money for projects to cut greenhouse gases blamed for global warming, Gore said the time was now right to stimulate the right kinds of investment to kickstart economies.

"In the United States, the largest amount of debt has been pulled up because of the purchase of foreign oil," he told a news conference.

"We need to substitute renewable sources of energy -- solar energy, wind energy and others -- in place of the very expensive and dirty oil and coal that's contributing to the debt crisis and the general financial crisis.

"It (the global financial slump) is in some ways a great opportunity for us to have these technologies before us... to revive economies."

Gore, who with the UN's Intergovernmental Panel on Climate Change won the Nobel Peace Prize last year, said renewable energy projects would create jobs, "stimulating the economy in the right way."