A species has just three options in the face of environmental change: move, adapt or die. As global temperatures rise many species are shifting their ranges, particularly towards the cooler poles and upslope to higher elevations. But if they can’t adapt or move, populations can be lost along the warmer edge of their range. These local population extinctions could have major implications for individual species, ecosystems and global biodiversity.
New research, published in PLOS Biology, warns that local extinctions caused by climate change are already widespread. The meta-analysis, by John Wiens of Arizona University, compiled data from 27 studies that resurveyed sites to see how species distributions had changed over time. These studies spanned a range of timescales between 10 and 159 years, and encompassed 976 species. Almost half of these (47 percent) had seen some local populations disappear along the warm edge of their range. Local extinctions were prevalent in all geographic regions and taxonomic groups.
“As Yogi Berra said, it is tough to make predictions, especially about the future,” said Wiens, whose research has contributed to a growing body of work that tries to forecast how biodiversity will respond to climate change. “And it is hard to tell whether your predictions are actually accurate or not. So, for this study, I changed my focus and instead asked: what has happened [due to climate change] already?”