Climate Change and Biodiversity
New study suggests that rising temperatures could reduce the lifespans of hundreds of species across the globe.
According to the IUCN Red List of endangered species, amphibians are the most threatened, with an estimate of 10,000 species of reptiles are heading for extinction. In the most comprehensive study to date, Queen’s University Belfast and Tel Aviv University Israel suggest evidence that global warming could have a huge impact on the life expectancy amongst cold-blooded creatures.
‘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,’ said Dr Daniel Pincheira-Donoso, co-author and Lecturer in Evolution & Macroecology at the School of Biological Sciences at Queen’s University Belfast.
According to the long-accepted ‘rate of living’ theory, the faster the metabolic rate the shorter the lifespan - the speed of the species’ internal body functions and how soon they start to reproduce determines 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. Analysing data from over 4,100 land vertebrate species, researchers found that ‘rate of living’ does not, in fact, affect aging rates, rejecting the previously accepted link between metabolism and lifespan.
The study, published in the Global Ecology and Biogeography Journal, found that rates of aging in cold-blooded organisms including amphibians and reptiles are linked to high temperatures, leading scientists to propose an alternative hypothesis: a hotter environment significantly cuts down lifespan.
‘The link between lifespan in cold-blooded animals 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,’ says Gavin Stark, lead author of the study and PhD student at Tel Aviv University.
Dr Pincheira-Donoso emphasises the need to further develop our understanding of the link between biodiversity and climate change in order to prevent further damage to the ecosystem.