Warning over loss of Amazon forest

One of the world's leading experts on climate change has predicted that rising global temperatures could destroy the Amazon rainforest, which in turn would cause a catastrophic build-up of carbon dioxide further accelerating global warming.

Tom Wigley, of the National Centre for Atmospheric Research in Boulder, Colorado, warned of the dangers that would occur if the world's biggest rainforest was lost – most likely as the result of lower rainfall levels over the Amazon basin that would occur in a warmer world.

In such a scenario, not only will the Earth have lost a major storage of carbon but it will lead to a huge release of carbon dioxide and methane, which are two of the most destructive greenhouse gases.

Such a model is called a positive-feedback mechanism, and although climatologists think it is a likely scenario, it is hard to predict accurately.

"It is very uncertain. Modelling the climate is difficult. Modelling the interactions between climate and vegetation is even more difficult," said Professor Wigley.

He added that it was important to start moving away from fossil fuels now rather than leaving it for future generations to deal with.