Things have been getting hotter: Since the Industrial Revolution, global temperatures have risen by just under one degree. However, studies often disagree about what impact this is having on the world’s species. Is the changing climate driving some species to the brink of extinction? Or are these species more resilient than we give them credit for?
To find out, professor Mark Urban from the University of Connecticut scrutinized 131 published articles on how climate change could affect global biodiversity. The problems with these studies, he says, is that since they focus on different species in different regions of the world, it’s difficult to draw any overall conclusion on how climate change might affect them. If we want to start drawing up plans on how best to tackle biodiversity loss, we need a bigger picture.
Urban says he also found that because so many studies used so many different methods, scientists could cherry-pick those that supported their view. This is what led him to carry out the meta-analysis that was published this week in Science. The statistical technique allowed Urban to look at the results of lots of different independent studies and then draw an overall conclusion.
The most well-known species at threat due to a warming climate is the polar bear (Ursus maritimus). Image credit: chbaum/shutterstock
What Urban found was that the future risk of extinction for species is “predicted not only to increase but to accelerate as global temperatures rise.” With a rise in temperature of just 2oC (35.6oF), which most experts believe will happen, the extinction risk almost doubles. If we follow our current, business-as-usual trend and the temperature rises by 4oC (39.2oF), climate change will threaten one in six (16%) species.
“All the studies are in pretty good agreement: The more warming we have, the more species we’ll lose,” says Dov Sax, a conservation biologist at Brown University who was not involved in the work. “This is really important to know, from a policy viewpoint.”
The study shows that risks are higher in South America, Australia and New Zealand, in part because they have more endemic species—those found nowhere else on earth—living in small ranges. Poorly studied regions, such as Asia, might also face a higher threat than is currently estimated, as most research so far has been carried out in North America and Europe.
This research should encourage policy makers and other researchers to better assess areas that could be set aside as parks or reserves. A conservation area set up today to protect one species might not be suitable ten years down the line, Sax notes, so it’s important that we look into the future when thinking these things through.
It’s probably best we don’t find out if Urban's predictions are right. With nearly 200 governments and world leaders meeting in Paris later this year for UN climate talks, let’s hope they can come to some sort of agreement to limit the rise in global temperatures.