species extinct Thompson's yucca is one of Arizona's plant species possibly at risk of extinction. |Public Domain Photo

Researchers found that a third of species could be extinct in 50 years if global warming is not reduced. 

The study, published Monday in the official journal of the National Academy of Sciences, looked at data from 538 species and 581 global sites.

Researchers from the university examined projections of future climate conditions, and the rate of species movement. They also took into account the recent extinctions of plants, insects, birds, reptiles, and amphibians to come up with their estimate.

“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,” researcher Cristian Román-Palacios explained in a press release

“We also estimated how quickly populations can move to try and escape rising temperatures,” he 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.”

Román-Palacios and fellow researcher John J. Wiens made another important finding from their experiments. The two determined that the key variable for explaining why a species will go extinct is a region’s hottest daily temperatures, rather than average yearly temperature. 

While global warming would affect all species, it’s expected to hit the tropics the hardest. The pair said many species will not be able to relocate to a cooler habitat fast enough to avoid extinction. 

“This is a big problem, because the majority of plant and animal species occur in the tropics,” Román-Palacios said in the release. 

How could these extinctions play out in Arizona? 

Wiens said he and his colleague think many species will be at risk due to the high summer temperatures in the state. 

The researcher said southern Arizona is a subtropical region home to some tropical species, one of which has already gone regionally extinct. 

“The Tarahumara frog is extinct in Arizona because of chytrid fungus, and chytrid-related declines seem to involve an interaction between the fungus and climate change,” he told The Copper Courier. 

Wiens also said species at risk of extinction in Arizona under worst-case scenarios include Thompson’s yucca, Schott’s agave, beargrass, alligator juniper, and the Gambel oak.