The human-caused climate crisis could cause the extinction of one-third of the world’s plant and animal species within 50 years, even accounting for species’ abilities to disperse and shift their niches to tolerate hotter temperatures, according to a study published this week in the journal Proceedings of the National Academy of Sciences.
Researchers at the University of Arizona analyzed 538 plant and animal species from around the world, 44 percent of which already faced local extinctions in at least one area in the world. What they discovered is that the areas that suffered from species extinctions had “larger and faster changes in hottest yearly temperatures than those without.”
Published in the Proceedings of the National Academy of Sciences, the study likely is the first to estimate broad-scale extinction patterns from climate change by incorporating data from recent climate-related extinctions and rates of species movements.
To estimate the rates of future extinctions from climate change, Cristian Román-Palacios, and John J. Wiens, both in the Department of Ecology and Evolutionary Biology at the University of Arizona, looked to the recent past. Specifically, they examined local extinctions that have already happened, based on studies of repeated surveys of plants and animals over time.
The team also estimated how quickly populations could move in an attempt to escape increasing temperatures. They found that about 50 percent of the species had local extinctions if maximum temperatures increased by more than 0.5 degrees Celsius and 95 percent if temperatures increase by more than 2.9 degrees Celsius.
Cristian said: “When we put all of these pieces of information together for each species, we can come up with detailed estimates of global extinction rates for hundreds of plant and animal species.”
“By analyzing the change in 19 climatic variables at each site, we could determine which variables drive local extinctions and how much change a population can tolerate without going extinct,” Román-Palacios said in the statement. “We also estimated how quickly populations could move to try and escape rising temperatures. When we put all of these pieces of information together for each species, we can come up with detailed estimates of global extinction rates for hundreds of plant and animal species.”
“In a way, it’s a ‘choose your adventure,'” one of the study’s authors, John Wiens, said in a statement. “If we stick to the Paris Agreement to combat climate change, we may lose fewer than two out of every ten plant and animal species on Earth by 2070. But if humans cause larger temperature increases, we could lose more than a third or even half of all animal and plant species, based on our results.”