Since he abandoned mainstream politics following his defeat in the 2000 presidential polls against George W Bush, Gore's personal fortune has risen from 1.2 million pounds to an estimated 60 million pounds, according to a report in the Daily Telegraph newspaper.

It is claimed that the Nobel peace laureate is on course to become the world's first "carbon billionaire" after significant investments in environmentally friendly projects like carbon trading markets, solar power, biofuels, electric vehicles, sustainable fish farming and waterless lavatories.

Global warming sceptics are not convinced about his "altruistic" climate change agenda. "Al Gore wants to become the first carbon billionaire and he is poised to do it," Marc Morano of climatedepot.com was quoted as saying by the Daily Telegraph newspaper.

"As much as Gore's made now, it is going to be a piker league compared to what he is going to make in five years if all these new carbon trading mandates go through," Morano claimed.