Global burnt area due to climate change likely increased by over 15%, shows attribution study
Climate change has likely increased global burnt area due to fires by more than 15 per cent between 2003 and 2019, according to a new attribution study.
The contribution of climate change to burnt area has risen by 0.22 per cent per year globally, with central Australia showing the largest increase, the study published in Nature Climate Change highlighted.
“Our study demonstrates that when fires do occur, the influence of climate change with drier and warmer weather conditions is increasingly significant,” Chantelle Burton, researcher at the Met Office Hadley Centre and joint lead-author of the first study, said in a statement.
Previous studies have not quantified the overall contribution of climate change to global fire regimes, the paper noted.
“We wanted to quantify the amount of burnt area we could attribute to climate change. It is no secret that climate change is affecting wildfires. However, how much climate change is affecting it, we don’t know. This is what we wanted to answer,” Seppe Lampe, PhD Researcher, Vrije Universiteit Brussel, told Down To Earth.
The Intergovernmental Panel on Climate Change (IPCC AR6) concluded that anthropogenic climate change has “likely increased fire weather in some regions of all inhabited continents”.
Other studies, however, have shown a decline in global total burnt area due to land-use change in the savanna regions. For instance, a 2017 study published in the journal Science concluded that the global burnt area declined by nearly a quarter between 1998 and 2015. This, according to the findings, was driven by agricultural expansion.
Burton and colleagues used global fire-vegetation models to study how climate change and socio-economic factors have influenced global and regional ‘burnt area’ from wildfires in forests and savannahs.
Their analysis showed that global burnt area increased compared to a world without climate change, with 15.8 per cent more global burnt area with climate change over the 2003–2019 period.
Further, Australia, South America, Western North America, and Siberia emerged as major fire-prone regions, with a median burnt area for the 2003–2019 period jumping by 22 per cent in northern Australia, 30 per cent in southeastern South America, 18 per cent in west Siberia and 15 per cent in western North America due to climate change.
“Some of these regions are sparsely populated, forested regions that are poorly adapted to fires. If longer periods of warm and dry weather become more frequent here, they will lead to bigger fires,” Lampe explained.
In densely-populated regions, on the other hand, one would expect there to be much more firefighting activity, which could better prevent these fires from becoming too large, the expert added.
In central, western and northeastern Africa, increases in burnt area due to climate change was 20.3 per cent, 2.7 per cent and 12.4 per cent, respectively.
The researchers also reported climate change-induced burnt area in 35 out of the 43 IPCC regions, with 13 regions showing an increase of more than 0.5 per cent annually for the 1980-2019 period.
In contrast, human activities have likely lowered global area by 19 per cent. Overall, the study concluded that there is a slight reduction of 5 per cent in global burnt area.
“For now, human activity has a bigger effect on reducing burnt area than climate change is increasing it. We do find that the effect of climate change is increasing (0.2 per cent per year), which implies that in the coming decades, this balance will reverse,” Lampe noted.
Though the net global change from climate change and human activities is small, the researchers have recorded larger changes on the regional scale, where the effect of climate change surpasses human activities in many regions, including central Australia, southern South America and west Siberia.
The researchers warned that the strength of the climate change influence is increasing rapidly and call for ambitious mitigation of climate change and adaptation.