Wildfires are becoming more frequent and are ravaging new parts of the world due to global warming. A study led by researchers from the University of Gothenburg shows that this change is increasing the vulnerability of thousands of plants, animals and fungi.
As global temperatures rise, the incidence of wildfires is increasing in many regions. This is mainly because higher average temperatures and changing weather conditions are drying out land and vegetation, making them more flammable. The study in Nature Climate Change shows that wildfires can break out closer to the poles than before. In some areas, the fire seasons may also double in length. This is under a medium scenario where the emissions don't sharply increase or get cut till the end of this century.
"Our research shows that wildfires pose an ever-increasing threat to biodiversity. We find that nearly 84 per cent of species vulnerable to wildfires will face a higher risk by the end of this century," says Xiaoye Yang, a researcher at the University of Gothenburg and the study's lead author.
Combines 13 climate models
Previous research into how biodiversity is affected by global climate change has mainly focused on gradual changes to habitats. Less attention has been paid to how climate-driven wildfires affect the long-term survival of plants and animals.
The research team, including Chalmers University of Technology, combined 13 climate models with a machine learning-based method to forecast changes in the wildfire burned area and the length of the fire season up to the end of this century. They then assessed how these changes affect the risk to species worldwide, based on a Red List from the IUCN (International Union for Conservation of Nature). The Red List includes 9,592 species whose survival is currently threatened by the increasing occurrence and severity of wildfires.
- Species with small ranges are particularly vulnerable. The most affected species are concentrated in South America, South Asia and Australia, and a large proportion of them are already endangered. An increase in the frequency of wildfires could push some of them closer to extinction, says Xiaoye Yang.
Even species that have previously been spared from wildfires are facing a new threat, but there is a lack of research to assess how serious that threat is.
Global trends of increasing risk
The researchers calculated the increase in wildfires based on the IPCC's various global warming scenarios. Under a moderate scenario involving a temperature rise of around 2.7 degrees compared with pre-industrial levels, the study shows that:
• The global area affected by wildfires could increase by around 9.3 per cent
• Fire seasons could be extended by 22.8 per cent
• Almost 84 per cent of species vulnerable to fire will face an increased risk of wildfires
The study highlights significant regional differences. Whilst the risk of wildfires is increasing in many parts of the world, certain regions in Africa may see a reduction in the area affected by fires due to a wetter climate in the future.
Climate action can reduce risk
The researchers also show that measures to limit emissions can significantly reduce the occurrence of wildfires. Compared with a high-emissions scenario, a future with moderate emissions could reduce the increase in species' vulnerability to wildfires by more than 60 per cent. Regions such as New Zealand, South America and areas near the Arctic would benefit most from reduced emissions.
"Current conservation strategies for vulnerable plants and animals risk underestimating future threats if they do not take into account disturbances such as wildfires," says Xiaoye Yang.
Scientific study in Nature Climate Change: Wildfire Risk for Species under Climate Change
