From Australia to Chile and all the way to Greece and Portugal, wildfires have put the international community on alert in recent years. Some fires have reached unprecedented proportions, like the fires that raged in California in 2021, burning more than a million hectares.
A new report from the United Nations Environment Programme (UNEP) warns these fires are going to happen more often as a result of anthropogenic climate change and other human activities. According to the report, wildfires may increase globally by 14% by the end of this decade and 50% by 2100 if no preventive actions are taken. Even places where fires are generally not expected to occur naturally, such as the Arctic and tropical forests, are at increased risk.
“Fires are going to be bigger, more intense, and more frequent,” warned coauthor Dolors Armenteras, a biodiversity conservation expert and professor at the National University of Colombia. These fires, as coauthor and land surface modeler at the UK Centre for Ecology and Hydrology Douglas Kelley pointed out, “are going to have disproportionate effects on the Global South.”
Mercedes Bustamante, a climate change expert and professor at the University of Brasília who was not involved with the UNEP report, said the document advances the discourse on wildfires in accordance with the latest reports from the Intergovernmental Panel on Climate Change (IPCC).
The IPCC’s most recent report, Bustamante said, emphasized the increase in megawildfires and attributed the change in fire regimes in several parts of the world to anthropic climate change. The UNEP report is a step forward, “as it clearly indicates the necessity of governments to get prepared more effectively and efficiently for this reality. It calls attention to the great losses we can face without adequate planning, as well as the need for multilateral coordination. Wildfires affect countries and social groups differently,” said Bustamante, who has contributed to previous IPCC reports.
From the Poles to the Tropics
“In the Amazon forest, for example, fire is used as a deforestation tool, and it is easy to get out of hand. With less moisture in the air due to climate change, fire burns more—not just [trees and brush that were] torn down, but also standing trees. This is how we get catastrophes,” Armenteras said.
“It’s a cycle that feeds back on itself,” she continued. Forest fragmentation leaves more vegetation exposed to the effects of heat and wind, and more deforestation means more biomass is available for burning. “More exposed patches of forest are easier to tear down and catch fire more easily. Tropical forests are humid if they are healthy and whole. If there’s water, they don’t burn that easily. But as they’re fragmented, they get drier and more exposed—and it gets worse with climate change,” Armenteras said.
The vulnerability of the Arctic also has researchers concerned. According to the report, thawing permafrost and further vegetation growth due to global warming are increasing the availability of flammable biomass on the ground. The 2020 Siberian heat wave that preceded fires in the Arctic Circle, for example, “was the first event shown to be almost impossible without climate change,” the UNEP report said, with chances of such an event happening once in 80,000 years without human-produced carbon emissions.
“Climate change is disproportionately affecting the Arctic,” said Chantelle Burton, a senior scientist at the Met Office in the United Kingdom and coauthor of the report. The region, like the Amazon and Indonesian rain forests, she noted, “is of special concern because there is a lot of carbon stored—which, if released, can contribute even further to accelerate climate change.” Besides, said coauthor Camilla Mathison, an adaptation expert and also a climate scientist at the Met Office, “the region is not adapted to fire.”
Prevention and Mitigation Can Make a Difference
More than an alarm, the report is a call to action, the authors said. “If we have a coordinated approach, we can handle this problem,” said Mathison. Armenteras agreed. “We cannot change the world’s topography, but land management actions can go a long way,” she said.
The report calls attention to the “5 R’s” of emergency management of wildfires: review and analysis (data from past events that can help in planning future responses), risk reduction (actions, such as land use planning, that can reduce the likelihood of wildfires), readiness (preparation of communities and fire services), response (actions to manage a wildfire when it occurs), and recovery (recovery actions during and after a wildfire).
Coauthor David Saah, professor and director of the Geospatial Analysis Laboratory at the University of San Francisco, said a number of actions are taking place across the world and could serve as examples for initiatives elsewhere.
In the Mekong region of Southeast Asia, he said, fires are caused by land clearing for farming. “There’s a mechanism under development for bridge funding to pay farmers for their harvested crops, to support them to clean their fields with heavy equipment instead of fire.”
In California, authorities are investing in fuel management strategies, Saah said. The Roadmap to a Million Acres, for instance, is a joint program of the U.S. Forest Service and the state of California aiming to prevent and mitigate fires in at least a million acres (400,000 hectares) yearly by 2025. “They are talking about an investment of 2 to 3 billion dollars per year,” he said. The financing, he added, “could involve businesses buying carbon credits and investing in local communities to counterbalance their emissions.”
These and other examples in the report reinforce Burton’s idea. “We want to pass on a message of hope: We haven’t lost everything yet.”
—Meghie Rodrigues (@meghier), Science Writer