Earth’s most extreme wildfires are growing more intense and frequent

A recent study published in the Nature Ecology and Evolution scientific journal broke down 21 years of satellite data to be the next in line to reveal a burning truth: extreme wildfire events are becoming more frequent and intense.

The study, led by researchers at Australia’s University of Tasmania, found that six of the past seven years have been among the most extreme wildfire years on record. The study also found the frequency of extreme wildfires  more than doubled between 2003 and 2023.

“This study provides concrete evidence of a worrying trend,” lead researcher Dr. Calum Cunningham told the university. “The intensity and frequency of these bushfires are increasing at an alarming rate, directly linked to the escalating effects of climate change.”

The research also confirmed that, while the total area burned is on the decline, fire behavior on the whole has worsened in several regions, including boreal and temperate conifer biomes in North America and Russia. Hotspots were also recorded in Australia, southern Africa, Mediterranean Europe, and South America. The burning of said biomes would reportedly hold dire implications for carbon storage, human exposure to wildfire, and significant ecological damage.

“The impact of these extreme events is devastating, not only for natural ecosystems but also for human populations,” Cunningham said. “These fires release significant carbon emissions, threatening to create a vicious cycle that further accelerates global warming.”

Australia's "Black Summer" bushfire season
Australia’s “Black Summer” bushfire season

Australia’s “Black Summer” fire season of 2019-2020 was named specifically for its unprecedented scale, intensity, and still-ongoing effects. The most recent “Black Summer” report on the bushfires focused on how they affected the nation’s tourism industry, specifically how previous reports underestimated the financial losses.

“Our novel research into the losses from the tourism shutdown resulting from Australia’s 2019-20 fires found that flowing on from direct impacts of AU $1.7 billion, indirect impacts along supply chains resulted in $2.8 billion in total output losses and $1.6 billion in reduced consumption,” the University of Sydney researchers’ report said. “We calculated significant spill-over costs, with total output losses being an increase of 61 percent on top of the direct damages identified.”

READ MORE: Australia’s ‘Black Summer’ bushfires impact on tourism still being uncovered

Siberian wildfire smoke increases could cause thousands of deaths, billions in costs for East Asia

A team from Japan’s Hokkaido University’s research study recently uncovered worrying findings for residents across East Asia. The team looked into the increasing frequency of wildfires in Siberia, and the growing threat of smoke that Japan and other areas downwind of Siberia are forced to breathe.

Previous studies have confirmed wildfires are becoming more common in Arctic biomes across the globe, including Siberia. A 2022 USFS study found wildfires in Siberia tripled from the 2001 – 2010 period to the 2011 – 2020 period. The area burned by wildfires in Siberia also increased by a factor of 2.6 during the same period.

Siberian smoke

“We found that annual fire frequency and the extent of burnt areas were related to various combinations of seasonal air temperature, precipitation, ground moisture, and lightning frequency,” the 2022 study said. “Increased wildfire and loss of permafrost may threaten ongoing settlement and industrialization, particularly for western Siberia.”

But the wildfires have implications for residents in numerous areas other than Siberia. The Hokkaido University researchers used global climate simulation models to evaluate how the expected increase in wildfires, and wildfire smoke, will affect people downwind of Siberia.

The researchers found smoke from Siberia’s wildfires releases aerosols, or air pollution particles that reflect sunlight away from the earth’s surface, which greatly degrades air quality, leading to a drastic increase in air pollution, possibly thousands of deaths, and billions of dollars in economic losses, including upwards of:

        • 70,000 deaths and $80 billion in losses across China
        • 32,000 deaths and $100 billion in losses in Japan
        • 4,000 deaths and $20 billion in losses in South Korea

Siberian smoke study

“Despite the limitations of our study, our findings provide readers with a critical message on the effect of increased particulate matter caused by Siberian wildfires on climate and air quality as well as mortality and the economy under present and future atmospheric conditions,” the researchers said. “Future studies must aim to prevent air pollution emissions from Siberian wildfires and take further preventive measures in the future under ongoing and future climate changes.”

Read the full study here.

A team from Japan’s Hokkaido University’s research study recently uncovered worrying findings for residents across East Asia. The team looked into the increasing frequency of wildfires in Siberia, and the growing threat of smoke that Japan and other areas downwind of Siberia are forced to breathe.

Soaring Himalayan wildfires don’t have only climate change to blame

Nepal has already seen 5,000 wildfires in 2024, the second-most wildfires recorded in a single year since record-keeping began in 2002. The fires have killed more than 100 people and have for days engulfed Kathmandu in hazardous wildfire smog.

“There is no respite from fires — both forest fires and house fires — continue to wreak havoc across the country in recent days,” the Kathmandu Post reported in April. “Massive fires have been raging across hectares of forest lands in more than a dozen places.”

Smoke from fires in Nepal -- NASA photo
A satellite fire map by NASA shows fire hotspots dotted across the bottom of the Himalayas, with a few creeping up the mountains. Image acquired by one of the Copernicus Sentinel-2 satellites on March 28, showing the region near Kathmandu engulfed in smoke.

The newfound prevalence of wildfires in the country has spiked researchers’ interest. A study published in the Climate Change scientific journal in 2023 analyzed the aftermath of 2021, Nepal’s worst wildfire year on record with 6,300 wildfires.

“In spring 2021, Nepal underwent a record wildfire season in which active fires were detected at a rate 10 times greater than the 2002–2020 average,” the study reported. “Prior to these major wildfire events, the country experienced a prolonged precipitation deficit and extreme drought during the post-monsoon period.”

Researchers concluded that both climate variability and climate change-induced severe drought played a factor in the country’s explosive wildfire growth. However, an environmental scientist stationed in Kathmandu recently told the Nature scientific journal that the study didn’t tell the full story.

Uttam Babu Shrestha, stationed at Kathmandu’s Global Institute for Interdisciplinary Studies, told Nature a large cause of increasing wildfires is the deterioration of Nepal’s relationship with its forests. A 1979 World Bank report warned that the nation was nearing an “ecological disaster” as a result of the country’s widespread deforestation and heavy reliance on agriculture. Nepal’s government listened and decentralized the management of its forests, resulting in the country’s forest cover nearly doubling in three decades. The abolition of the country’s monarchy and transition to a federal system, however, left forest management by the wayside.

“But this new political atmosphere didn’t prioritize the management of community forests like before,” Shrestha said. “With no clear benefits coming out of forests, the locals don’t feel the same ownership.”

A proposal to lessen both wildfire severity and forest management inaction was proposed by the lead researcher of the 2023 study. Binod Pokhrel, a climate scientist at Tribhuvan University in Kathmandu, found that Nepal’s 282 weather stations could work together to inform community members.

“By using weather station data, we could precisely forecast drought index up to a local ward level,” Pokhrel told Nature. “The lack of management of increasing forest cover can easily lead to another disaster.”

Pokhrel proposed that a smartphone-based fire forecast would reduce the chance of fires getting out of control — and save lives. The International Centre for Integrated Mountain Development uses a similar idea to update its wildfire-monitoring webpage, but Pokhrel told Nature that the Nepalese government must be involved to safeguard against future disastrous wildfires.

Smoke temporarily covered nearly all U.S. lakes between 2019 and 2021

As wildfire activity and severity increase globally, so too does the pervasiveness of wildfire smoke.

Researchers in the U.S. are working to find out how growing amounts of wildfire smoke nationwide affect ecosystems including aquatic habitats. A recent study published in the Global Change Biology research journal found that even smoke impacts lake ecology.

“An incredible 98.9 percent of lakes experienced at least 10 smoke-days a year, with 89.6 percent of lakes receiving over 30 lake smoke-days, and lakes in some regions experiencing up to 4 months of cumulative smoke-days,” the study said.

lake smoke

The term “smoke-days” describes the number of days on which any portion of a lake’s boundary intersected with smoke as defined by NOAA’s hazard mapping system daily smoke product. The smoke-days concept has been used previously to demonstrate smoke exposure by ecoregion, but was used specifically for lakes for the first time in this study.

Smoke and ash from wildfires lower the solar radiation that enters lake habitats, affecting organisms in numerous ways from physiology to behavior, according to the research. Particles from the smoke deposited within lake ecosystems can also affect several biological and geological processes, including the availability and cycling of various nutrients.

Less than 0.01 percent of land in North America burned between 2019 and 2021, but the area covered in smoke was 75 percent of the continent’s total land. The year 2021 marked the largest number of high-density lake smoke-days and is the year with the largest portion of the country burned and largest area covered with smoke, while 2020 had the lowest number of high-density smoke-days and the smallest area burned and smallest area covered with smoke.

“Large knowledge gaps impede our ability to predict and manage the responses of lakes to smoke and ash,” the researchers concluded. “Measuring the extent and effects of smoke and ash deposition remains challenging. Larger-scale studies are necessary to disentangle the mediating effects of scale and watershed context on the responses of lakes to smoke and ash deposition.”

Read the entire study here.

‘Let burn’ narrative put to the test on USFS lands

Fires not fully suppressed but herded around and allowed to burn have allegedly been an unofficial USFS practice since the 1970s. A new study challenges whether that practice is as common as many believe.

The naming convention for the practice has reportedly changed repeatedly. They were originally called “let burn” fires, but forest managers soon dropped the term because a pervasive misunderstanding quickly arose that wildland firefighters were ignoring fires and letting them run amok. Even though other terms like “Natural Wildland Fires” and “Managed Fire” took the “let burn” term’s place, the incorrect view of the practice has persisted, being referenced as recently as in 2021’s Tamarack Fire.

That lightning-caused fire forced the evacuation of nearly 2,000 residents, destroyed 25 structures, and burned 67,000 acres in California and Nevada. Many members of the public blamed the fire’s negative outcomes on the supposed “let burn” practice, despite the policy’s not formally existing.


PREVIOUS COVERAGE:
Tamarack Fire lifts evacuation orders for nearly 2,000 residents


Researchers from the USFS Rocky Mountain Research Station wanted to put the “let burn” narrative to the test — by quantifying the damage from consequential lightning-caused fires such as the Tamarack Fire.

The study, published in SpringerOpen Fire Ecology scientific journal, used multiple sources of fire-reporting data to identify numerous USFS fires from 2009 to 2020 using management strategies similar to those used during the Tamarack Fire. Of the 940 wildfires that burned within that time, the researchers found only 32 fires with characteristics similar to the Tamarack, nearly half of which ignited within wilderness areas.

Woodbury Fire Phoenix Roosevelt
The Superstition Wilderness inside the perimeter of the Woodbury Fire, June 22, 2019. InciWeb.

The researchers found that firefighter hazard mitigation was the primary driver on 26 of the 32 wildfires, with only six of the fires managed for “resource objectives” like the reported “let burn” fires. Risks posed to firefighters from terrain, snags, or inaccessibility were by and large what fire managers are concerned about during a wildfire — not how they can let the fire burn for potential ecological gains, or for the oft-alleged “treatment acreage quota.”

ICS-209“Our results suggest that a ‘let burn’ strategy is not a predominant USFS management approach,” the researchers concluded. “A limited palette of strategic reporting categories may be partially responsible for the falsely premised ‘let burn’ narrative.”

Researchers theorized that a large reason for the pervasiveness of the “let burn” misconception is how fire managers fill out ICS-209 forms post-fire. Managers select one of four categories to classify the intent behind their decisions, including “monitoring,” “confine,” “point or zone protection,” or “full suppression.” The subtlety that’s lost on which option is chosen —  any option other than full suppression — may be responsible for the spread of misinformation on the fire’s management.

“These categories may not capture enough of the nuance and complexity of the decision environments in which they are made,” said the Rocky Mountain Research Station. “In turn, this information gap may permit inaccurate explanations to dominate the conversation.”

Western legislators introduce National Prescribed Fire Act of 2024

Oregon, Washington, and California legislators have reintroduced a bill poised to create a national prescribed burn collaborative program and increase the practice nationwide.

Oregon Senator Ron Wyden reintroduced the National Prescribed Fire Act of 2024 [PDF] on Tuesday, three years after the act’s first attempt died in committee. Representative Kim Schrier of Washington, Representative David Valadao of California, and Senator Alex Padilla of California joined the act’s push.

The act would invest $300 million in hazardous fuels management and increase prescribed burn plans, preparations, and practices through both the USFS and DOI. The funds are required to be used to develop a prescribed burn strategy for each USFS or BLM region, implement prescribed fires on federal land, and fund an increase in prescribed burn crew staffing.

Prescribed fire, Indiana Dunes National Lakeshore near Ogden Dunes in northwest Indiana in 2013. NPS photo.
2013 RxFire at Indiana Dunes National Lakeshore near Ogden Dunes, northwest Indiana — NPS photo

It would also put $10 million toward the collaborative prescribed burn program based on the previous USFS Collaborative Forest Landscape Restoration Program (CFLRP). The previous program, one of the first national efforts that encouraged collaborative landscape restoration, ran from 2009 to 2019 and focused on reducing wildfire risk, enhancing watershed health, and benefiting local rural economies. The program reported its results to Congress, saying it successfully restored 5.7 million acres of forest while creating nearly $2 billion in local labor income.

The 2024 act has the support of numerous conservation agencies and fire officials, including The Nature Conservancy, which has been conducting Rx burns in Oregon since 1983.

“Prescribed fire is an essential tool to restore and steward fire-dependent ecosystems, reduce the risk of extreme wildfire to communities, and help many of Oregon’s most iconic natural landscapes adapt in the face of climate change,” said Katie Sauerbrey, Oregon fire program director at The Nature Conservancy. “We are grateful for Senator Wyden’s leadership on the National Prescribed Fire Act — providing a pathway to accelerate the pace and scale of prescribed fire necessary to combat the wildfire crisis in the western United States.”

The bill’s full text is posted [HERE].

Oregon, Washington, and California legislators have reintroduced a bill poised to create a national prescribed burn collaborative program and increase the practice nationwide.