Climate change will affect more than a third of wildlife habitats by 2085: Study

There have been 100 documented cases where an extreme weather event caused a population decline of more than 25%, and 31 records of a species disappearing locally after such an event.

Mumbai: More than a third of wildlife habitats on land will suffer multiple extreme weather events by 2085 due to climate change, according to a new study to be published in the journal Nature Ecology and Evolution.

That’s compared to less than 10 per cent if we cut fossil fuel use fast enough to stick to the Paris Agreement target of less than 2°C warming by 2100.

The study, authored by an international team of 18 scientists, and led by the Potsdam Institute for Climate Impact Research (PIK), charted the change in droughts, heatwaves, river floods and wildfires for amphibians, birds, mammals, and reptiles globally. Extreme weather events can cause mass mortality of animals and reduce populations significantly.

There have been 100 documented cases where an extreme weather event caused a population decline of more than 25 per cent, and 31 records of a species disappearing locally after such an event.

“I think climate change, and in particular extreme events, are still really being underestimated when it comes to conservation planning. It’s not just going to be a gradual shift of temperature over many years,” commented lead author Stefanie Heinicke, a postdoctoral researcher at PIK.

According to the study, two or more extreme weather events hitting wildlife in close succession often makes the damage even worse. After the 2019-2020 “Black Summer” fires in Australia, plant and animal species declined 27-40 per cent more in areas where the fires were preceded by drought.

Heatwaves are one of the most frequent and damaging extreme weather events; the 2019/20 Australian heatwave killed more than 72,000 flying foxes. According to this study, in the year 2000 just 18 per cent of species’ habitats were exposed to heatwaves. This will rise to 65 per cent by 2085 if we stick to the Paris Agreement targets, but 93 per cent on our current climate trajectory.

Species with small habitat ranges face particularly severe risks, such as the Carnaby's Black Cockatoo which declined 60 per cent due to the 2011 Western Australian heatwave. In the year 2000 no bird species faced having more than 75 per cent of their habitat range exposed to heatwaves - this would rise to nearly 3,800 bird species by 2085 if we stick to the Paris Agreement targets and more than 9,800 bird species on our current trajectory. Cutting fossil fuel use rapidly would more than halve the number of bird species affected by heatwaves.

This study is likely the first to quantify wildfire exposure for animals. In 2020, wildfires in the Pantanal in Latin America killed an estimated 17 million vertebrate animals. In the year 2000 only 11 amphibian species globally had more than 25 per cent of their habitat range exposed to wildfires.

If we meet Paris Agreement targets this rises to nearly 500 species by 2085, but on our current emissions pathway over 3,400 amphibian species would be affected in this way; nearly seven times more amphibian species than if we cut fossil fuel use now. The Amazon basin, southern Africa, and Southeast Asia will be hotspots for increased wildfire frequency.