Up to 36 per cent of animal habitats on land could be exposed to multiple extreme climate events by 2085, according to a new international study.
A Simon Fraser University researcher was part of an international team that used climate impact modelling to project how much of the planet's land animals' habitat would experience multiple extreme heat waves, wildfires, droughts or river floods under low- to high-emissions scenarios over the next 60 years.
"We were looking at what percentage of amphibian, bird, mammal and reptile land habitats would experience repeated extreme events such as back-to-back heat waves or a heat wave followed by a wildfire," says Sian Kou-Giesbrecht, a contributing author of the study.
"When extreme events happen again and again or close together, it leaves very little time for species to adapt or recover."
Led by the Potsdam Institute for Climate Impact Research (PIK) and published in Nature Ecology & Evolution, the study used models to translate climate projections into climate impacts.
At low emissions, in line with the Paris Agreement limiting warming to below 2 degrees C, exposure stays within moderate levels at nine per cent. But experts say if we move into high‑emissions scenarios, projections illustrate a massive increase with 36 per cent exposed to extreme events.
"This study shows that even robust conservation strategies can only go so far," Kou Giesbrecht says. "At some point, limiting biodiversity loss depends on climate change mitigation - specifically, reducing fossil fuel emissions."
The findings build on other studies that show similar increases in human exposure to extreme events under high emissions scenarios, she adds.
Heat waves, wildfires pose the greatest threat
Researchers found heat waves accounted for the largest projected impact. Under high‑emissions scenarios, 74 per cent of land species' habitat ranges will be exposed to heat waves by 2050.
Extreme wildfires are projected to be the second most prevalent event, affecting 16 per cent of animal habitat on land by 2050 and increasing to 25 per cent by 2085 in high-emissions scenarios.
Species‑rich regions such as the Amazon basin, Africa and Southeast Asia are projected to be among the hardest hit. However, the study likely underestimates future exposure in Canada, Kou‑Giesbrecht says.
That is largely because current global climate models do not adequately simulate boreal and high‑latitude wildfire behaviour. Canada‑specific modelling is underway in other research, she adds.
"Canadians are understandably proud of our beautiful lands and the species we share them with," she says.
"We can help protect them by staying within Paris Agreement targets to limit warming, alongside robust conservation strategies that account for escalating climate impacts."
SFU expert available
SIAN KOU-GIESBRECHT, assistant professor, School of Resource and Environmental Management, Liber Ero Chair in Climate Action
