And if we don’t watch out, we will lose half of all species by that time.
Not all plant and animal species can cope with climate change. Many species cannot live in a warmer climate, which means that they are currently facing an uncertain future. At present, 28,338 animal species are threatened with extinction ; an unprecedented high number. But the future is even more bleak. Because in fifty years’ time, a third of all species that live on earth may be affected by climate change.
Analysis
The researchers decided to dig through scientific studies to find out which species have already died out locally. They focused in particular on the recent past. Because in this way, the researchers hoped to make an accurate estimate of how many species might die in the future due to climate change. The team then analyzed data from 538 species and 581 places on Earth. And the findings are quite disturbing. The researchers discovered that 44 percent of the 538 species have already died out at one or more locations.
Estimate
This information then helped to make an estimate about the future. “By analyzing changes of 19 climate variables at each location, we were able to determine which variables cause local extinctions and how much change a species can handle before it becomes extinct,” explains researcher Cristian Román-Palacios. “We also estimated how quickly populations can move in order to escape rising temperatures. When we combine all these pieces of information for each species, we can make detailed estimates for at least hundreds of plant and animal species. ”
Temperatures
The most important variable that best explains whether a species is about to die out is the maximum annual temperature. Surprisingly, the researchers discovered that the average annual temperature only slightly fluctuates in the places where local extinctions occurred. And that while the average temperature is being used on a large scale as an indication of overall climate change. “This means that results can be misleading when we look at changes in the average annual temperature to predict extinction due to climate change,” explains researcher John Wiens.
Migration
Some species are able to migrate to cooler areas in order to escape from a warmer climate. Yet this is not very promising. The researchers have established that most species cannot move quickly enough. It appears that many species can tolerate small increases in the maximum temperature, but only to a certain extent. About fifty percent of a species dies locally if the maximum temperature rises by more than 0.5 degrees Celsius. 95 percent even die if it is about 2.9 degrees Celsius warmer.
The findings from the study emphasize how disastrous temperature increases can be for plant and animal species. It means that if we continue as we are today, we will have to miss many species by 2070. “If we can live up to the goals of the Paris Climate Agreement, we will lose fewer than two out of every ten plant and animal species on Earth in fifty years,” Wiens concludes. “But if we cause greater temperature rises, more than a third or even half of all species may have disappeared.” Moreover, the researchers expect that the species in the tropics will be hit the hardest. “That’s a big problem,” says Román-Palacios, “because most plant and animal species live in these regions.”