If unabated, climate change could wipe out 1 in 6 species on the planet by the end of the century – that is 16% of all wildlife on Earth – according to a new study published Thursday in the journal Science.
"Global biodiversity provides the foundation for economy, culture, food, and human health," said Mark Urban, an ecologist at the University of Connecticut and the author of the extinction study. Unfortunately, "if we continue on our current trajectory of greenhouse gas emissions, we face losing one in six species,” according to The Verge.
The impacts of climate change on wildlife have been known for years; increasing sea temperatures are causing more coral reefs to “bleach” – or die, while the melting ice in the Arctic is endangering the survival of polar bears. Urban’s study, however, points out just how devastating the impacts can be.
Accelerated Extinction
The planet is experiencing a new wave of die-offs driven by factors such as habitat loss, the introduction of exotic invaders and rapid changes to our climate. Some people have called the phenomenon the sixth mass extinction, in the same vein as the catastrophic demise of the large dinosaurs 65 million years ago.
To try and combat the declines, scientists have been racing to make predictions about which species are most likely to go extinct, along with when and where it will happen, sometimes with widely varying results.
“Depending on which study you look at, you can come away with a rosy or gloomy view of climate change extinctions,” Urban noted. “That’s because each study focuses on different species [and] regions of the world and makes different assumptions about climate change and species’ responses.”
To conduct the study, Urban compiled 131 previously published studies in order to produce an analysis of climate-induced extinctions risks.
"Perhaps most surprising is that extinction risk does not just increase with temperature rise, but accelerates," he asserted
Urban's study also revealed the highest-risk areas are South America, Australia and New Zealand, where climate change could potentially decimate 14 to 23 percent of many species. The lowest-risks areas are North America and Europe. And in one model of climate change, Urban assumed a modest rise in temperature - only 2 degrees Celsius, compared with temperatures recorded before the Industrial Revolution.
Even using that figure, which is widely considered an underestimation, the extinction risk for any species of animal almost doubles, to 5.2 percent from 2.8 percent. Should temperatures increase by 4.3 degrees Celsius, however, 16 percent of the world’s species could find themselves at risk for extinction.
Beyond Climate Change
While habitat loss and hunting are currently the top threats, climate change will be "the number one driver of extinctions in the medium to long term", Marco Lambertini, director general of the WWF conservation group, told Reuters.
Jamie Carr, a species expert at the International Union for Conservation of Nature (IUCN), said the study was a "very well- educated guess", but that it was impossible to isolate the impact of warming from the host of other threats, such as human overpopulation and urbanization.
So far, he said that no species had been driven to extinction solely by a changing climate. The IUCN says warming contributed to the extinction of the golden toad, last seen on a Costa Rican mountaintop in 1989.
The study found little difference in the risks faced by different groups of animals. Some other studies suggest that birds will be able to fly to new habitats while less mobile creatures such as frogs and salamanders may suffer most from changing temperatures.
This study comes ahead of the UN climate change conference in Paris in December, which aims to curb greenhouse gas emissions in the hopes of reducing global temperature increase to 2 degrees Celsius above pre-industrial levels. Every country is expected to attend the conference to plan a global deal.
