Uncontrollable wildfires are intensifying with the rise in greenhouse gas emissions, according to a sweeping global report released Wednesday by the United Nations Environment Program and nonprofit GRID-Arendal, who said communities are not prepared for the escalating damage.
The authors of the report define an extreme wildfire as “an unusual or extraordinary free-burning vegetation fire” that harms society, the economy or the environment. Such fires are burning longer, hotter and more intensely, often evading control, and have even moved into territory that should be waterlogged or frozen, such as peatland and permafrost.
“Fires are changing because we are changing the conditions in which fire occurs,” it said.
Due to a combination of climate change and land use change, there has been a “dramatic shift” in wildfire patterns worldwide. Some areas, such as the Arctic, will probably experience a significant increase in burning by the year 2100. Tropical forests in Indonesia and the southern Amazon are also expected to experience increased fires if greenhouse gas emissions continue unchecked.
The report was spurred by a series of wildfire disasters in 2017 in Portugal, Canada and California — shocking events that have reemerged in subsequent years in new locations, but often under similar conditions, such as extreme heat, drought, high winds and overgrown or mismanaged landscapes.
Released as the U.N. Environment Assembly convenes in Nairobi on Feb. 28, the report calls for a radical shift in how humans manage wildfires, from an approach that emphasizes firefighting to one that looks to prevent catastrophic fires, as communities learn to live with such blazes.
Extraordinary fires around the globe
The vast majority of vegetation fires on the planet are benign and help the environment, but a small percentage have become extreme, with devastating effects. “From Australia to Canada, the United States to China, across Europe and the Amazon, wildfires are wreaking havoc on the environment, wildlife, human health, and infrastructure,” the report stated.
“We had to define wildfires for our purposes to be those that are unusual or extraordinary and do cause concern,” said Andrew Sullivan, a wildfire scientist with the Commonwealth Scientific and Industrial Research Organization (CSIRO) in Canberra, Australia, and an editor and author of the report. “We needed to come up with a definition that encompassed the whole spectrum of potential wildfire behavior.”
That definition may include flames that are leaping from tree canopies or those that crawl through peatlands but still emit a tremendous amount of carbon into the atmosphere.
The past five years have seen numerous wildfire episodes that once were considered rare or extreme scenarios:
- In 2017 and 2018, a series of wildfire disasters in Portugal, Greece, California and British Columbia sounded alarm bells and seemed to usher in a new age of wildfires. Deadly and destructive blazes continued in 2020 in the Pacific Northwest and in California, which saw its worst fire season on record with 4 million acres burned. In 2021, extreme fires again descended on western North America, destroying two rural towns and chewing through millions of acres of forest. All were associated with extreme heat, drought and/or dangerous fire weather.
- Australia’s 2019-2020 fire season saw extreme fires raging for many months. Fueled by record-shattering temperatures, severe drought and fierce winds, fires encroached on populated areas during the continent’s “Black Summer,” killing 33, with nearly 500 additional deaths attributed to the health effects of smoke.
- In 2020, the world’s largest tropical wetland, the Pantanal in South America, burned following severe drought and scorching weather. Nearly a third of this biodiversity hot spot — which stretches across Brazil, Paraguay and Bolivia — was lost, and likely many endangered species along with it.
- Wet forest ecosystems in South America and other regions are seeing unusual fire activity because of human activities such as logging, road construction, agriculture and mining. The loss of tree canopy in disturbed forests promotes the growth of fuels on the forest floor; exposed, these then dry out quickly, and are vulnerable to fire spread. Recent studies have shown a staggering loss of trees and biodiversity following fires in wet forests.
- In 2020, wildfires in the Russian Arctic burned tens of millions of hectares following spring and summer temperatures that were 4 to 6 degrees Celsius above normal. It was the latest in a string of large-scale fires in recent years, in a region that is warming at twice the rate of the rest of the planet. The burning of Arctic peatland threatens to turn a crucial carbon sink into a carbon source.
Studies have linked several recent wildfire episodes to climate change, including the 2017 wildfires in British Columbia, Australia’s Black Summer of 2019-2020 and the 2020 wildfires in the Arctic, and the extreme 2021 heat wave that preceded wildfires in British Columbia and the Pacific Northwest.
From firefighting to land stewardship
As fire behavior becomes more intense, firefighting becomes less effective and more dangerous. In the face of extreme fire weather, it can be futile.
“We’re spending an enormous amount of money on suppression, particularly in the developed world,” said Peter Moore, an author of the report and a forestry fire management consultant with the Food and Agriculture Organization of the United Nations. “That solution has run its course — in my opinion, it’s reached its limits.”
In addition to curbing greenhouse gas emissions, the most effective way to reduce fire intensity and protect communities is to reduce the amount of vegetation and debris available to burn, through prescribed burning, mechanical thinning, animal grazing and other practices.
In some parts of the world, a large part of the problem is that a sense of land stewardship has been lost with the decline of family farming and Indigenous knowledge, Moore said, as city dwellers with little land-tending experience have moved into rural areas.
In Australia and North America, for example, Indigenous practices of the past, like cultural burning, “were almost completely obliterated, but we can tap into them with collaboration with Indigenous people,” he said. “How you re-create that sort of gentle persistent, consistent interaction with the landscape — that’s what you need.”
Don Hankins, a professor of geography at California State University at Chico and an author on the report, said Indigenous people have historically not been permitted to practice burning on ancestral homelands in the United States, though policies are beginning to shift following recent severe fire seasons in the U.S. West and around the world.
The authors hope the report will shed light on the complexity of the problem — one that does have solutions that work, but no silver-bullet pathway out of the current quagmire. They also hope that the U.N. Environment Program will serve as a clearinghouse of information for one country to learn from the wildfire experience of another.
“No single country has yet formulated the perfect response, but many are making progress in different aspects of managing the risks of wildfires,” the report states. “Together we can learn from each other.”
Diana Leonard is a science writer covering natural hazards based in California. You can follow her on Twitter @HazardWriter.