According to a new study, nearly one-third of species on our planet could face extinction by the end of the century if humans do not reduce greenhouse gas emissions. This risk increases as global warming intensifies. A team led by Mark Urban, a biologist and ecologist at the University of Connecticut, warns that if global temperatures rise more than 1.5 °C above pre-industrial averages—exceeding the target set by the Paris Agreement—the extinction of species will accelerate rapidly. This is particularly true for amphibians, as well as species in mountainous, island, and freshwater ecosystems, and those found in South America, Australia, and New Zealand.
The climate crisis is causing shifts in temperature and changes in precipitation patterns, which inevitably impact the survival of various species. For instance, rising temperatures have disrupted the migration patterns of monarch butterflies, causing them to arrive before the plants they pollinate have bloomed. Many animals and plants are moving to different latitudes or higher altitudes in search of more favorable temperatures. However, numerous species are unable to adapt to these new environmental conditions, leading to population declines and, in some cases, extinction.
What did the scientists discover? Mark Urban’s team analyzed over 30 years of research on biodiversity and climate change, encompassing more than 450 studies on most known species. The findings are concerning. If greenhouse gas emissions are regulated according to the Paris Agreement, approximately 180,000 species—about one in fifty worldwide—will be at risk of extinction by 2100. If temperatures rise by 2.7 °C, one in twenty species could disappear. Hypothetical warming beyond this threshold would dramatically increase the number of species facing extinction. If global temperatures rise by more than 4.3 °C, 14.9 percent of species could be affected. And if the increase exceeds 5.4 °C, as much as 29.7 percent of Earth’s biodiversity could vanish.
Mark Urban told Live Science that the number of species at risk will sharply increase once the 1.5 °C warming target is surpassed. However, if global warming remains below this threshold, in line with the Paris Agreement, the risk of extinction will not rise significantly, he noted. Amphibians are particularly vulnerable, as their life cycles are heavily dependent on weather conditions and are extremely sensitive to droughts and changes in precipitation patterns. Species in mountainous, island, and freshwater ecosystems are also at high risk, likely due to the isolation of these environments, which makes migration and the search for more favorable climates difficult.
Limiting greenhouse gas emissions could slow down warming and help prevent species extinction worldwide. Understanding which ecosystems are most affected by climate change will help direct conservation efforts where they are needed most. The results of this research were published in the journal Science.