According to a new study, climate change may already be driving lizards to extinction. Researchers say that the downfall of lizards may be due to the way global warming is affecting their reproduction.

The study, from University of Exeter and the University of Lincoln, focused on the arrival and growth of Liolaemus lizards which evolved from being oviparous (producing eggs) to viviparous (producing live babies). The lizards changed their reproduction style to suit the climate, which was very cold. However, the transition from oviparity to viviparity is irreversible and the lizards aren't able to cope with the rising temperatures.

"Climate change must not be underestimated as a threat to modern patterns of biodiversity. Our work shows that lizard species which birth live young instead of laying eggs are restricted to cold climates in South America: high in the Andes or towards the South Pole. As the climate warms, we predict that these special lizard species will be forced to move upwards and towards the pole, with an increased risk of extinction," said Dr. Dave Hodgson, from Biosciences at the University of Exeter, in a news release.

Researchers charted out these lizards' evolution and estimated their rates for survival in a world that's getting warmer. They found that the lizards may vanish in the next few decades.

Previous research from the Proceedings of the Royal Society has shown that even lizards living in forests are vulnerable to rising temperatures and are likely to disappear soon.

According to another study published in the journal Science, it is estimated that roughly 40 percent of all lizards today will be extinct by the year 2080.

"These lizards are one of the most diverse groups of animals, and are able to adapt to remarkably diverse conditions. Unfortunately, a reduction in cold environments will reduce their areas of existence, which means that their successful evolutionary history may turn into a double-edged sword of adaptation. Their extinctions would be an atrocious loss to biodiversity," said Dr Daniel Pincheira-Donoso from the University of Lincoln's School of Life Sciences and lead author of the study.

The study 'The evolution of viviparity opens opportunities for a lizard radiation but drives it into a climatic cul-de-sac' is published in the journal Global Ecology and Biogeography.