Cranking up the Earth’s temperature may eventually increase biodiversity instead of stifling it, according to a new study published this week in The Proceedings of the National Academies of Science. The new data overturn previous results from the study’s lead author, evolutionary ecologist Peter J. Mayhew of the University of York, and—at first blush—seem to contradict the mass extinctions now accompanying a rise in global temperatures.
Mayhew and his colleagues studied the fossil records of marine invertebrates and found that periods of warmer temperatures over the past 540 million years had the most biodiversity. Unlike Mayhew’s previous study of the same period, which found that rising temperatures reduces biodiversity, the new study controlled for geological eras that have been more thoroughly studied than others, and thus have more fossils on record.
“The improved data give us a more secure picture of the impact of warmer temperatures on marine biodiversity,” Mayhew said in a press release. “[O]verall, warm climates seem to boost biodiversity in the very long run, rather than reducing it.”
But that doesn’t mean that the current bout of extinctions linked to global warming will reverse or slow anytime soon, as the pace with which temperatures rise affects the rate of extinctions and evolution of new species. And the study focused on much longer time-scales than that of human’s influence on the environment.
“[Our results] do not suggest that current global warming is good for existing species,” said University of Leeds Professor and study co-author Tim Benton in the press release. “Increases in global diversity take millions of years, and in the meantime we expect extinctions to occur.”
The next step, Mayhew told Nature, will be to look at climate transitions over short periods, which more closely resemble our current global temperature spike. “The time periods we're really interested in now,” he said, “are decades and hundreds of years—at maximum 1,000 years.”