They have been around since the time of the dinosaurs and have in the past survived several global mass extinctions of species, but now lizards are at serious risk of disappearing from the face of the earth as a result of climate change, scientists said yesterday.

An international study has found that as many as 20 per cent of the 3800 species of lizards could be extinct by 2080 if global temperatures continue to rise as predicted. In some parts of the world 12 per cent of the lizard populations studied since 1995 have already disappeared - and researchers are blaming climate change.

Lizards, which include geckos, iguanas and chameleons, are often referred to as cold-blooded creatures but in fact their body temperature rises and falls with their exterior environment. They have to bask in the sun to raise their body temperature, and seek shade when it gets too warm.

Scientists fear that, in many parts of the world, temperatures have become too warm for the local lizards to be able to stay out during the hottest part of the day to catch enough food, causing the animals to weaken and die.

"The results were clear. These lizards need to bask in the sun to warm up, but if it gets too hot they have to retreat into the shade, and then they can't hunt for food," said Professor Barry Sinervo of the University of California, Santa Cruz, who led the study published in the journal Science. Other scientists have already documented an alarming loss of amphibian species - frogs, toads and newts - as a result of a complex interaction with a fungal infection and possibly climate change. But the latest study, which involved constructing a computer model to predict future extinctions, clearly points to rising temperatures alone for the decline of lizards.

- Independent