Editor’s summary
Because it is clear that human activities are altering the global climate, researchers have been studying potential effects and predicting declines and extinctions. Understanding the consequences globally requires the synthesis of many studies. Following up on an initial effort nearly 10 years ago, Urban found that we can expect, with increased certainty, that rising temperatures will lead to an increasing number of extinctions, with the highest emission scenario leading to extinction of nearly a third of the Earth’s species, especially those from particular vulnerable taxa or regions. —Sacha Vignieri
Abstract
Climate change is expected to cause irreversible changes to biodiversity, but predicting those risks remains uncertain. I synthesized 485 studies and more than 5 million projections to produce a quantitative global assessment of climate change extinctions. With increased certainty, this meta-analysis suggests that extinctions will accelerate rapidly if global temperatures exceed 1.5°C. The highest-emission scenario would threaten approximately one-third of species, globally. Amphibians; species from mountain, island, and freshwater ecosystems; and species inhabiting South America, Australia, and New Zealand face the greatest threats. In line with predictions, climate change has contributed to an increasing proportion of observed global extinctions since 1970. Besides limiting greenhouse gases, pinpointing which species to protect first will be critical for preserving biodiversity until anthropogenic climate change is halted and reversed.