Climate Change Boosts Extinction Risks, Biodiversity at Stake

Climate change is driving global extinction risks, with 1.6% of species threatened at 1.3°C of warming and risks escalating to 29.7% at 5.4°C, according to a new meta-analysis encompassing more than 30 years of research. Climate change is reshaping ecosystems and biodiversity globally, altering species distributions, interactions, and population dynamics. While some species adapt or migrate to track shifting climates, others face population declines, shrinking ranges, and potential extinction. Recent global biodiversity assessments forecast extinction risks for over a million species, though the specific contribution of climate change to these predictions remains unclear. Effective conservation efforts to protect this biodiversity require an understanding of these risks globally, but to do so requires a comprehensive synthesis of many datasets. To produce a quantitative estimate of extinctions attributable to climate change, Mark Urban performed a formal meta-analysis that incorporates more than 5.5 million individual projections from 485 studies covering most known species. The author's analysis greatly advances prior assessments by tripling the number of studies included and leveraging sophisticated modeling approaches that account for species' sensitivity and adaptability to climate change. According to the findings, under current global temperatures, which are currently 1.3°C above preindustrial levels, 1.6% of species are expected to face extinction. As temperatures rise to 1.5°C – the Paris Agreement's target – extinction risks increase to 1.8%, and further to 2.7% at 2.0°C. With international emission targets leading to a projected 2.7°C rise, 1 in 20 species will be at risk. Beyond this, extinction risks escalate sharply; 14.9% at 4.3°C and 29.7% at 5.4°C. Amphibians; species from mountain, island, and freshwater ecosystems; and species inhabiting South America, Australia, and New Zealand face the greatest threats.