Climate change could cut lifespan of cold-blooded species – study

Scientists say their findings suggest global warming could have a huge impact on the life expectancy of some animals.
Climate change 'could reduce lifespan among cold-blooded species'

Climate change could reduce the lifespan of hundreds of species, new research suggests.

Scientists say their findings suggest global warming could have a huge impact on the life expectancy of cold-blooded species – reptiles and amphibians.

The researchers from Queen’s University, Belfast and Tel Aviv University analysed data from more than 4,100 land vertebrate species globally to test the prevailing rate of living theory.

They found that rate of living does not affect ageing rates, rejecting the previously accepted link between metabolism and lifespan.

Dr Daniel Pincheira-Donoso, co-author and lecturer in evolution and macroecology at Queen’s University, said: “Our findings can have critical implications for our understanding of factors that contribute to extinctions, especially in modern times when we are facing a worldwide decline of biodiversity, with cold-blooded animals being particularly endangered.

“Now we know that the life-expectancy of cold-blooded vertebrates is linked to environmental temperatures, we could expect to see their lifespans further reduced as temperatures continue to rise through global warming.”

For a long time the rate of living theory has been accepted as to why organisms age.

It sets out that the faster the metabolic rate the shorter the lifespan.

In other words, the faster the species lives in terms of the speed of internal body functions and how soon they start to reproduce, or how slowly in terms of these internal body functions and of lower reproductive rates, will determine how long they live.

This explains why some vertebrates, like frogs, can only live for a few months while others, such as whales and turtles, can live for centuries.

But the new study challenges the theory which is more than 100 years old.

Until now the theory had not been tested at a global scale with all land vertebrates and there were limitations with the range of species it was tested on.

The study, published in Global Ecology and Biogeography, found rates of ageing in cold-blooded organisms including amphibians and reptiles are linked to high temperatures.

These findings led the scientists to propose an alternative hypothesis – the hotter the environment is, the faster the rate of living that in turn leads to more accelerated ageing and a shorter lifespan.

Nearly one in five of the world’s estimated 10,000 species of lizards, snakes, turtles, crocodiles and other reptiles are threatened with extinction.

Gavin Stark, lead author and PhD student at Tel Aviv University and first author, said: “The link between lifespan in cold-blooded animals (amphibians and reptiles) and ambient temperatures could mean that they are especially vulnerable to the unprecedented global warming that the planet is currently experiencing.

“Indeed, if increasing ambient temperatures reduces longevity, it may make these species more prone to go extinct as the climate warms.”

The scientists say understanding about the link between biodiversity and climate change needs to be developed.