Summers in the Arctic-boreal region are becoming increasingly defined by fire. In 2023, Canada endured its worst wildfire season in history, with nearly 200,000 Canadians displaced. Fast forward to summer 2025, and the country faces its second-worst wildfire season on record, with 470 outbreaks deemed “out of control” by August. Siberia and Alaska are also confronting active fire seasons.
For Arctic communities, the physical impacts of smoke exposure, the toll of evacuations and destruction, and the threats to cultural traditions compound the danger of extreme fires. But Indigenous science and cultural traditions offer a path towards justice and resilience.
Climate change has created hotter and drier conditions in the north, increasing the frequency and intensity of Arctic-boreal wildfires. These wildfires amplify global warming, creating a feedback loop by burning deep into permafrost, a carbon-rich soil, and releasing stored carbon dioxide and methane into the atmosphere. A recent study led by Permafrost Pathways researchers found that wildfire has contributed to the Arctic’s shift from a net absorber to a net emitter of carbon. That increase in emissions in turn fuels even more fires. Between 2003 and 2023, the Arctic-boreal region saw a sevenfold increase in extreme wildfires.
“Things have really changed in our traditional territories,” said Woodwell Climate’s Adaptation Specialist, Brooke Woods. Woods is a Tribal member from Rampart, Alaska, and she currently lives in Fairbanks, Alaska. “We had two fires close to Rampart this summer. We’ve had back-to-back fires over the past three summers. Growing up, I don’t ever recall back-to-back wildfires surrounding our communities.”
The increase is also due, in part, to increased lightning strikes, which are occurring more frequently as warming temperatures further destabilize atmospheric conditions, leading to more storms that produce lightning.
“Our summers are drier and we’re having more severe heat events as well as more intense lightning and thunderstorms now, too,” said Woods. “When we had the fire in Rampart, in the midst of this wildfire, one of the storms actually produced 1600 lightning strikes across Alaska.”
The history of colonialism in North America has also played a role in today’s extreme wildfire regimes. For millennia, Indigenous Peoples across the Arctic practiced cultural burning—using small, controlled fires to manage the land, reduce dry fuel buildup, and prevent large, catastrophic wildfires. These practices not only protected ecosystems but also supported biodiversity and were deeply rooted in cultural knowledge and tradition. However, colonization disrupted these systems as Indigenous communities were forcibly removed from their lands, and cultural burning was often banned and criminalized altogether.
“Elders risked jail time for burning,” Dr. Amy Cardinal Christianson told Chatelaine Magazine. Christianson is a Metis wildfire expert and Policy Advisor for the Indigenous Leadership Initiative who co-hosts the podcast Good Fire and serves on the board of the International Association of Wildland Fire. “That’s how badly they knew that the land needed to burn.”
This erasure, combined with colonial fire suppression tactics, has led to the accumulation of flammable undergrowth that makes the land more vulnerable to intense and widespread fires.
Increasingly active Arctic-boreal wildfires are not just environmental disasters, they’re also cultural and human crises.
Wildfire smoke—which can contain soot and high levels of mercury— threatens the health of Arctic communities and can put vulnerable groups, like elders, young children, and those with pre-existing health conditions, at prolonged risk well after the fires have gone out.
“In my baby’s first year of life in 2023, we had such bad air quality [in Fairbanks]. It impacted his respiratory system, and it was just so hard for him to be able to nurse,” said Woods. “I was even considering driving 300 miles to the next urban area to get him to clean, healthy air because there was also a fire in Rampart. It impacted our safety in both of the places that we call home.”
The mental toll of wildfires can also be just as devastating as the physical impacts, as communities must navigate evacuation logistics, loss, and displacement with very little governmental support.
“Communities are thinking about how the wildfire crisis is real—it’s driven them from their home and maybe destroyed their home—they’re thinking ‘what else am I going to lose’?” said Edward Alexander, Senior Arctic Lead at the Woodwell Climate Research Center, Chair of Gwich’in Council International, and Co-Chair of the Arctic Council’s Expert Group on Wildland Fire. “Then, becoming unhoused… people lose their jobs, their businesses, or their investments. They lose forward momentum in their life.”
In addition, evacuation is far more complicated in the Arctic. Many remote communities and villages in Alaska and Canada either have only one main road or aren’t connected to road systems at all, making them accessible only by plane or boat, which presents a logistical and financial challenge for mass evacuation. The combined impacts of smoke, heat, and economic insecurity can also present impossible choices.
“If you look at not only the health disparities but your income, what can you afford to keep yourself healthy?” said Woods. “Can you afford air filters for your home? Can you afford and have access to air conditioners with filters? Because not only are you battling the smoke, but you’re also battling this heat. So just navigating those at different income levels can be very complex.”
Fire doesn’t just destroy infrastructure and threaten health and well-being, it also disrupts Indigenous ways of life, cultural connections to land, intergenerational knowledge sharing, language revitalization, and cultural history tied to specific places like hunting trails, fish camps, and seasonal migration.
“When we were still able to subsistence fish in Alaska, and had wildfires at the same time, there were community members in Rampart that were not able to meet all of their subsistence needs due to wildfires,” Woods said.
In Good Fire, Christianson discusses ways to restore the modern world’s broken relationship with fire and the need to integrate systems that not only respond appropriately but are also proactive and predicated on Indigenous Knowledge and expertise. This is where cultural burning offers a way forward—a way to view fire not as a threat, but as a critical tool for keeping land healthy and communities safe.
The First Nations Emergency Services Society (FNESS) and the Indigenous Leadership Initiative (ILI) recently released the “Create a Cultural Burn Pathway” workbook to support Indigenous communities in creating cultural burn programs to reduce wildfire risk and maintain healthy connections to the land.
“Fire doesn’t have to be scary,” said Christianson in a video produced by the Indigenous Leadership Initiative. “It doesn’t have to be something we live in fear of every summer. We can have a better relationship with fire that can have really important benefits.”
Traditional burning is a culturally grounded, community-empowered, and ecologically practical approach to managing and mitigating wildfire risk in the North, born from generations of Traditional Ecological Knowledge. Unlike conventional fire suppression, which often seeks to eliminate fire altogether, cultural burning is a proactive, place-based practice rooted in Indigenous governance, values, and ecological understanding. These approaches aren’t about fighting fire—they’re about embracing it to foster sovereignty, revitalize knowledge, and deepen connection to the land.
Beyond the health of the land and forests, cultural fire also contributes to cultural resilience and maintains Indigenous connections to land and community. Cultural burns ensure practices are guided by traditional protocols and adapted to local ecosystems. Community members, including youth, are involved—passing knowledge between generations and restoring cultural roles that were disrupted by colonization.
Which is why, according to Alexander, placing the emphasis on the health of the forest, ecosystems, and community overall, rather than on controlling fire, should be the real goal.
“We should be thinking a little differently,” Alexander said. “Cultural fire is a tool, but fire is not the emphasis. It’s the health of the forest, it’s the health of the land, it’s the health of the animals and birds, it’s the health of our peoples and communities. That’s the emphasis.”
Cultural burning is just one part of the solution, which will involve moving away from colonial fire suppression methods altogether and supporting Indigenous-led fire stewardship models with meaningful changes in policy and funding. Woods says she’d like to see Indigenous-led fire programs represented as part of a broader recognition of Indigenous sovereignty in the North.
“I’d like to see more local people leading the work rather than just renting out their equipment or hiring them as boat captains,” Woods said. There are more opportunities for Indigenous People to help their own communities. I feel there’s always time to course correct and really acknowledge and honor the 229 Tribes of Alaska and their practices that have maintained very healthy land and ecosystems for so long.”
In Alaska, Indigenous-led wildfire initiatives—like the U.S. Bureau of Land Management (BLM) Emergency Firefighter (EFF) program—create opportunities for local members of Alaska Native communities to join crews and integrate their traditional knowledge and expertise of the land to help keep their communities safe. In Canada, Fire Guardian programs—which Dr. Christianson has long been advocating for—aim to get good fire back on the land through Indigenous stewardship and traditional practices.
Alexander says he hopes recognizing cultural burning and other forms of Indigenous Knowledge as legitimate science will help prioritize them in land management.
“It’s critically important science that we need to help us manage the wildland fire crisis in the circumpolar north,” said Alexander.
Alexander imagines a future where wildfire becomes mildfire. Where communities in the north are adequately resourced and wildfire management becomes proactive and rooted in Indigenous Knowledge and expertise, while prioritizing and supporting sovereignty.
“Indigenous fire management looks like a vibrant landscape where you don’t have severe wildland fire, but you have increased biodiversity, where the vegetation is more nutritious for the plants and animals, and that permafrost and other hugely important resources are protected,” Alexander said. “I also think that it’s an integral part of respecting the sovereignty of Indigenous Peoples, of respecting the self-determination of Indigenous Peoples to manage our territories how we see fit, and I think that it’s a really critical approach that we need to all be listening to. Our collective future really depends on it.”
In the northern ecosystems of the Alaskan boreal forest and tundra, wildfire is a natural – and even necessary – process. But as temperatures rapidly warm, wildfire frequency and severity in the state are breaking historical records.
Scientists at Woodwell Climate Research Center are studying the effects of these increased fires on the ecosystem. In a study published earlier this year, a research team led by Research Scientist Dr. Scott Zolkos examined the relationship between northern wildfires and one concerning byproduct of them: mercury pollution.
In the last 25 years, Alaska has experienced some of the worst fire seasons on record. One of the reasons behind this is that climate change is hitting the north harder than other regions.
Northern latitudes, including the Arctic and boreal regions, are warming three to four times faster than the rest of the planet. As warmer temperatures melt snow earlier in the year and dry out soil and vegetation, the fire season lengthens and intensifies. According to Woodwell scientists, 2024 was the second-highest year for wildfire emissions north of the Arctic Circle.
“It’s really sort of a new phenomenon, the level of burning we’re seeing in the tundra,” Dr. Brendan Rogers, Senior Scientist, says.
Increasing fires means increasing air, water, and ecosystem pollution from the byproducts of burning vegetation and soils. Mercury is a toxic pollutant in wildfire smoke, but there is sparse research on mercury release from northern peatland wildfires which means scientists don’t yet have a great understanding of how increasing northern wildfire activity could counteract efforts to curtail human-caused mercury release. To understand these impacts, Zolkos and collaborators studied areas of the Yukon-Kuskokwim (YK) Delta in southwestern Alaska— a peatland environment that burned in 2015. The summer of 2015 made history as one of Alaska’s worst fire seasons, with over 5 million acres of land burned.
The research team used peatland soil samples that were collected between 2016 and 2018 by undergraduate participants of The Polaris Project to measure mercury. They then used the new mercury data together with organic carbon and burn depth measurements from another recent study to develop models that predicted mercury emissions from the 2015 wildfires.
Mercury continuously cycles through the environment in air, water and soil, often changing between liquid and gaseous forms. It enters the atmosphere as emissions from human activities like the burning of fossil fuels and natural processes like wildfires and volcanoes. High levels of mercury can accumulate in the ground when vegetation takes up mercury from the atmosphere, then decomposes and deposits it into the soil. In northern peatlands, mercury has been accumulating with organic matter for thousands of years.
Mercury emissions occur when wildfire burns organic matter in soil and releases mercury that is bound to it back into the atmosphere. With increased temperatures and wildfire activity, the stabilization accumulation of mercury in the soil is threatened – and so is air quality.
“There are huge mercury stores in northern peatlands,” Zolkos says. “If peatlands burn more, it could potentially offset global efforts to reduce human mercury release into the environment.”
Zolkos and collaborators found that levels of mercury in peat in the YK Delta were similar to those in peatlands elsewhere in the north. Using an atmospheric chemical transport model developed by collaborators, the researchers also found that mercury deposition within 10 kilometers of wildfire sites was two times higher than normal, even though the majority of emissions from the fire traveled beyond Alaska.
With this information, Zolkos believes that increasing fire activity has the potential to unlock large amounts of soil-bound mercury in the North. The challenge now is figuring out exactly how much mercury is being released and where it ends up.
As a step to understanding this, Zolkos is leading a pilot project to develop an atmospheric mercury monitoring network across wildfire-susceptible peatlands in Alaska and Canada. Twenty-six air samplers, which collect mercury molecules in the air, were deployed at seven sites in Arctic-boreal peatlands across Alaska and Canada during the summers of 2024 and 2025. After the 2025 summer season is complete, the samplers will be sent to a lab at Harvard University, where Zolkos will measure their mercury content.
“Our goal is to work with collaborators to deploy these simple and cost-effective samplers that capture mercury in the atmosphere,” Zolkos says. “And from that, we can back-calculate the concentration of mercury in the air to understand wildfire impacts.”
By studying trends, Zolkos can compare levels of mercury in the air in areas affected and not affected by wildfire. And with added contextual data, scientists can model how much mercury might have been released from the soil and vegetation by wildfire.
In addition to containing mercury, wildfire smoke also emits particulate matter (PM2.5). PM2.5 refers to particles that are smaller than 2.5 micrometers in diameter – thirty times smaller than the average human hair. When breathed in, they can affect the heart and lungs and cause a variety of health problems, including aggravated asthma, decreased lung function, and increased respiratory symptoms.
Together with collaborators from the Permafrost Pathways project, Zolkos is also collaborating with Alaska Native communities to install PurpleAir sensors, a system of particulate matter monitors, to support tribally-led wildfire air pollution monitoring. This project helps to address monitoring needs in Alaska, where nearly 90% of rural communities reached or exceeded unhealthy levels of PM2.5 at least once due to wildfire in the last two decades.
“It’s a really great opportunity to work together with Alaskan Native communities and also to share knowledge, learn from them, and try and help them with any needs that they have for environmental monitoring,” Zolkos says.
So far, particulate matter sensors have been deployed in Pond Inlet in Nunavut, Canada, Churchill in Manitoba, Canada, and Akiachak, Alaska.
“The complex impacts of wildfire on Arctic and global communities is not something that can be solved by taking a measurement and seeing a number alone. These climate health impacts require a more holistic way of thinking and doing research” Dr. Sue Natali, Senior Scientist and lead of the Permafrost Pathways project, says. “What gives me hope is that the Western scientific community is now listening and hearing more from Indigenous partners to co-produce research to support climate resilient communities,”
As the Arctic heats up three to four times faster than the rest of Earth, hotter temperatures have super-charged northern fires, causing them to burn more area, more frequently, and more intensely.
These fires have a range of harmful impacts on communities, ecosystems, and wildlife in the north. When it comes to carbon, they represent a unique now-and-future threat to global climate. That’s because much of the boreal forest, which circles the high northern latitudes, is underlain by carbon-rich frozen ground called permafrost. Stocked with carbon from dead animal and plant matter that’s accumulated over hundreds to thousands of years, permafrost functions as Earth’s “deep freezer,” keeping the planet cool by keeping carbon out of the atmosphere.
When permafrost thaws, microbes begin to access and break down the once-frozen carbon, releasing it to the atmosphere where it contributes to warming. Wildfires accelerate this process by burning off the organic soil layer that protects permafrost— opening the door on the freezer. And as temperatures in the north rise and boreal forests dry out and experience greater climate stress, the fires these forests evolved with have become more frequent and severe, with consequences for both permafrost and our climate.
The boreal forest, the largest forested biome on Earth, covers large stretches of North America, Europe, and Russia and stores 25% of the planet’s terrestrial carbon. Roughly 80% of this carbon is stored belowground in the form of soil organic matter and permafrost. So when the forest burns, the carbon released from the trees is just the tip of the iceberg. Eighty percent or more of carbon emissions from boreal fires in North America and in central Siberia come from belowground combustion of soil organic matter.
Boreal forests have been reliable safekeepers of this belowground carbon historically by providing an insulating soil organic layer that protects permafrost. But increasingly severe fires are changing that picture.
Wildfires threaten this belowground carbon in boreal forests in multiple ways, both during and long after the fire itself.
As a fire burns, it combusts the carbon stored in trees and plants, releasing it into the atmosphere along with smoke and harmful pollutants. Intense fires also burn through duff and soil layers that carpet the forest floor.
Burning these insulating layers exposes the permafrost below to warmer temperatures for years after a fire. A recent synthesis study led by Postdoctoral Researcher Dr. Anna Talucci of Woodwell Climate found that in burned sites across the boreal and tundra regions, the depth of seasonally thawed ground increased for two decades after a fire.
That means that long after a fire is extinguished, permafrost is still thawing and releasing carbon in the form of carbon dioxide and methane. Where this ground is rich in ice, it can sink and collapse after a fire, causing ponding, erosion, and creating bogs and wetlands that release methane.
All of this carbon released to the atmosphere contributes to further warming, which in turn contributes to drying forests, hotter temperatures, and more lightning ignitions in the boreal forests. That’s because warming has boosted both lightning ignition efficiency, or the likelihood that lightning starts a fire, and the number of lightning strikes in the region.
Average yearly burned area across Alaska and Canada has roughly doubled since the 1960s. Emissions from Canada’s 2023 fire season exceeded total fossil fuel emissions from every other nation except the U.S., China, and India for that year. And the frequency of extreme wildfires across the circumpolar boreal region increased seven-fold from 2003 to 2023.
These trends, amplified by the permafrost-fire feedback, worsen both Arctic impacts and global emissions and could hamper our ability to meet agreed-on climate goals.
Wildfires in boreal forests are already weakening the region’s carbon storage capacity, signalling a crucial shift in the global climate system. Addressing critical gaps in our understanding of the fire-permafrost feedback will help prepare for such shifts and their local and global implications.
Research teams including Permafrost Pathways and collaborators are refining tools to predict what increasing fires mean for regional and global carbon emissions and climate targets. Such insights are needed to inform the Intergovernmental Panel on Climate Change’s (IPCC) inventory of global emissions, which does not yet include fire emissions or fire-caused permafrost thaw emissions. Efforts to better model and predict the complex interactions between permafrost and fire are also critical to informing adaptation and management responses.
The region’s vastness, as well as geopolitical conditions, presents challenges to collecting field data. Here, modeling can help scale the insights from what field data is available. And developing more accurate fire maps in Alaska and Siberia, where less burned area satellite data exists, could equip researchers and communities with better near-real-time information. Long-term monitoring efforts that study pre- and post-fire conditions, such as those led by Łı́ı́dlı̨ı̨ Kų́ę́ First Nation at the Scotty Creek Research Station, are providing critical insights about fire’s acute and long-term effects on permafrost.
The impacts from widespread severe northern wildfires transcend boundaries, affecting health and ways of life for communities living in the Arctic and around the globe.
But there are solutions at hand. Cultural burning, an important practice for many Arctic Indigenous communities, can help boreal forests build resilience by removing fuels with low-intensity seasonal fire. And collaborative management approaches that suppress fires in permafrost regions have been shown to be a cost-effective climate mitigation tool that has co-benefits for human health and the global climate.
But the most important solution to help keep the global wildfire-permafrost feedback loop in check is to reduce greenhouse gas emissions. Lowering overall emissions will slow rising temperatures in the north and give communities, boreal forests, and other ecosystems a better chance to recover and to adapt.
Explore these 15 maps by award-winning Woodwell Climate cartographers Greg Fiske and Christina Shintani. Created in 2024, each tells a story about the immense beauty of the high north, the dramatic changes unfolding as the Arctic continues to warm three to four times faster than the rest of the world, and the equitable solutions being developed to address climate impacts in the region
Read More on Permafrost Pathways.
“What if you’re not on the map?”
Dr. Kelsey Leonard of the Shinnecock Indian Nation addressed this question to a room of Geographic Information System (GIS) professionals at Esri’s global mapping conference in 2023. Leonard, who uses maps to advance Indigenous water justice, asks this question to raise awareness about the absence of Indigenous land and languages in GIS tools. The removal of traditional place names in physical spaces, cartographic maps, and geospatial software often contributes to the erasure of Indigenous culture and history.
The Permafrost Pathways project, like Leonard, is working to change that.
Read more on Permafrost Pathways
Woodwell Climate’s Government Relations team led the Center’s third annual D.C. fly-in this September, and you might say the third time was the charm.
“It was really impressive to see how we’ve built over the three years of doing the fly-in,” said Laura Uttley, Director of Government Relations. “The scale and scope of meetings, having five of 13 Congressional meetings be with Members themselves, and to have 17 Board members, senior leaders, and scientists participate—it’s just really exciting.”
Over the course of three days, the Woodwell Climate delegation tackled a range of near-term legislative priorities, such as the Natural Climate Solutions Research and Extension Act, standalone legislation that is currently being considered as part of Farm Bill negotiations and was adapted in the House version of the Farm Bill as “soil health research,” as well as longer-term policy development and relationship building.
Engagements spanned the full diversity of Woodwell Climate’s work. Meetings with leadership of the House Climate Solutions Caucus and Conservative Climate Caucus focused on the economic impacts of climate change and the need for expanded national climate services to make risk information available to all communities. A Permafrost Pathways delegation, including representatives of Alaska Native partner communities, shared a range of perspectives on rapid Arctic change with Alaska legislators and the Senate Indian Affairs Committee. One group talked with staff in the office of Rep. Paul Tonko (D-NY) of New York about carbon markets, and with Rep. Bill Keating (D-MA) and Sen. Ed Markey (D-MA) about Massachusetts-based research, including river monitoring and wetland restoration. Woodwell Climate also met with Democratic Whip Katherine Clark (D-MA) and Rep. Pete Aguilar (D-CA), Chair of the Democratic Caucus, to discuss opportunities to advance and protect climate policies, especially as leadership considers agendas for the next Congress.
Across all the sub-teams and meetings, Uttley says three big takeaways stood out:
That Woodwell’s delegation secured thirteen Congressional meetings—five of them with Members themselves, including leadership of key committees and caucuses—is a testament to the Center’s credibility and the depth of relationships that the Government Relations team is building. A summer of high-profile Supreme Court decisions, the end of the fiscal year looming, and a tumultuous election cycle all contributed to a chaotic energy on the Hill in September, and legislators were only in session for three weeks between their summer recess and a break for election activities. Despite those pressures, Uttley says lawmakers and their staff were enthusiastic and engaged.
She attributes that to months (years, really) of relationship building grounded in a “here’s where we agree, and here’s how we can help” approach. An enormous amount of time and thought goes into crafting meeting agendas and materials that meet legislators where they are, address their needs and interests, and highlight common ground and opportunities for progress.
Consistency is also key, Uttley says. While individual Members come and go, and the political climate shifts, Woodwell Climate’s annual fly-in and growing year-round presence in Washington, D.C. are reminders that we are a reliable resource of information, and in it for the long haul.
Meetings with individual legislators and/or their staff can be incredibly productive, but time is limited. Briefing an entire committee or meeting with leadership of a caucus group can be an effective way to get scientific expertise and policy priorities to many legislators at once. For example, part of the Woodwell delegation met with leadership of the bipartisan Climate Solutions Caucus (more than 60 members), staff for the House Sustainable Energy and Environment Coalition (100 Democratic members), and staff for the Conservative Climate Caucus, which has more than 80 Republican members, all interested in pragmatic climate solutions. These larger groups are also less susceptible to disruption through election cycles, which creates opportunities to work on policy agendas with a longer runway.
Maps on the table, personal accounts of climate impacts, data tailored to a legislator’s district, and plain language science summaries were all on display during the fly-in, and Uttley says the Center’s commitment to making climate science relevant and accessible is a distinguishing feature that opens doors and builds relationships.
“To be able to find hooks and make climate science accessible for such a range of audiences on so many different topics is really impactful,” Uttley said.
Overall, Uttley said being in the room as scientists, community members, and policymakers —and seeing the energy they all came away with—left her with one overarching takeaway: Change is possible and “the Climate Science for Change motto is actually lived; it’s not just something we say.”
Fire is a necessary element in northern forests, but with climate change, these fires are shifting to a far less natural regime— one that threatens the ecosystem instead of nurturing it.
Boreal tree species, like black spruce, have co-evolved over millennia with a steady regime of low-frequency, high-intensity fires, usually ignited by lightning strikes. These fires promote turnover in vegetation and foster new growth. On average, every 100 to 150 years, an intense “stand-replacing” fire might completely raze a patch of forest, opening a space for young seedlings to take root.
But rapid warming in northern latitudes has intensified this cycle, sparking large fires on the landscape more frequently, jeopardizing regeneration, and releasing massive amounts of carbon that will feed additional warming. Here’s how climate change is impacting boreal fires.
In order for a fire to start, you need three things— favorable climatic conditions, a fuel source, and an ignition source. These elements, referred to as the triangle of fire, are all being exacerbated as boreal forests warm, resulting in a fire regime with much larger and more frequent fires than the forests evolved with.
Forest fires only ignite in the right conditions, when high temperatures combine with dryness in the summer months. As northern latitudes warm at a rate three to four times faster than the rest of the globe, fire seasons in the boreal have lengthened, and the number of fire-risk days have increased.
In some areas of high-latitude forest, climate change has changed the dynamics of snowfall and snow cover disappearance. The rate of spring snowmelt is often an important factor in water availability on a landscape throughout the summer. A recent paper, led by Dr. Thomas Hessilt of Vrije University in collaboration with Woodwell Associate Scientist, Dr. Brendan Rogers, found that earlier snow cover disappearance resulted in increased fire ignitions. Early snow disappearance was also associated with earlier-season fires, which were more likely to grow larger— on average 77% larger than historical fires.
The second requirement for fires to start is available “fuel”. In a forest, that’s vegetation (both living and dead) as well as carbon-rich soils that have built up over centuries. Here, the warming climate plays a role in priming vegetation to burn. A paper co-authored by Rogers has demonstrated temperatures above approximately 71 F in the forest canopy can be a useful indicator for the ignition and spread of “mega-fires,” which spread massive distances through the upper branches of trees. The findings suggest that heat-stressed vegetation plays a big role in triggering these large fires.
Warming has also triggered a feedback loop around fuel in boreal systems. In North America, the historically dominant black spruce is struggling to regenerate between frequent, intense fires. In some places, it is being replaced by competitor species like white spruce or aspen, which don’t support the same shaded, mossy environment that insulates frozen, carbon-rich soils called permafrost, making the ground more vulnerable to deep-burning fires. When permafrost soils thaw and burn, they release carbon that has been stored—sometimes for thousands of years—contributing to the acceleration of warming.
Finally, fires need an ignition source. In the boreal, natural ignitions from lightning are the most frequent culprit, although human-caused ignitions have become more common as development expands into northern forests.
Because of lightning’s ephemeral nature, it has been difficult to quantify the impacts of climate change on lightning strikes, but recent research has shown lightning ignitions have been increasing since 1975, and that record numbers of lightning ignitions correlated with years of record large fires. Some models indicate summer lightning rates will continue to increase as global temperatures rise.
There is also evidence showing that a certain type of lightning— one more likely to result in ignition— has been increasing. This “hot lightning” is a type of lightning strike that channels an electrical charge for an extended period of time and tends to correlate more frequently with ignitions. Analysis of satellite data suggests that with every one degree celsius of the Earth’s warming, there might be a 10% increase in the frequency of these hot lightning strikes. That, coupled with increasingly dry conditions, sets the stage for more frequent fire ignitions.
So climate change is intensifying every side of the triangle of fire, and the combined effects are resulting in more frequent, larger, more intense blazes that contribute more carbon to the atmosphere. While the permanent solution to bring fires back to their natural regimes lies in curbing global emissions, research from Woodwell Climate suggests that firefighting in boreal forests can be a successful emissions mitigation strategy. And a cost effective one too— perhaps as little as $13 per metric ton of carbon dioxide avoided, which puts it on par with other carbon mitigation solutions like onshore wind or utility-scale solar. It also has the added benefit of protecting communities from the health risk of wildfire smoke.
Rogers, along with Senior Science Policy Advisor, Dr. Peter Frumhoff, and Postdoctoral researcher Dr. Kayla Mathes have begun work in collaboration with the Yukon Flats National Wildlife Refuge in Alaska to pilot this solution as part of the Permafrost Pathways project. Yukon Flats is underlain by large tracts of particularly carbon-rich permafrost soils, making it a good candidate for fire suppression tactics to protect stored carbon.
The project will be the first of its kind— working with communities in and around the Refuge as well as US agencies to develop and test best practices around fighting boreal fires specifically to protect carbon. Broadening deployment of fire management could be one strategy to mitigate the worst effects of intensifying boreal fires, buying time we need to get global emissions in check.
The second round of 2024 Fund for Climate Solutions (FCS) awardees has been announced. The FCS advances innovative, solutions-oriented climate science through a competitive, internal, and cross-disciplinary funding process. Generous donor support has enabled us to raise more than $10 million towards the FCS, funding 69 research grants since 2018. The latest cohort of grantees includes three projects focused on driving impact through collaboration and community-building, and three projects exploring new horizons in technology with timely policy relevance.
Increasing wildfire activity in northern high-latitude regions is threatening global climate goals and public health. When organic matter in soils and vegetation burns, greenhouse gasses, fine particulates (PM2.5), and contaminants including mercury are released to the environment. Currently, there is sparse data for understanding how wildfires contribute to the northern mercury cycle, as well as gaps in infrastructure for monitoring PM2.5 in Alaska Native communities. This project will develop a network to measure and monitor the release of mercury and PM2.5 from wildfire, with an emphasis on peatlands. Leveraging ongoing work by Permafrost Pathways, the team will install mercury sampling equipment on existing eddy covariance flux towers across Alaska and Canada. Alongside Permafrost Pathways and their tribal partners, the team will also consult with Alaska Native communities in the Yukon-Kuskokwim Delta to co-develop a tribally-led air quality monitoring program.
Many of the Woods Hole science community’s cutting-edge researchers, including several scientists at Woodwell Climate, are developing creative, do-it-yourself (DIY) tools using relatively simple components to further explore their research questions. However, despite the six institutions’ similar applications and geographic proximity, there are few opportunities for exchange and knowledge, both across Woods Hole institutions and more broadly with Cape Cod educational institutions. The project team will convene a one-day workshop to bring together aquatic, atmospheric, and terrestrial science researchers and educators from the Woods Hole science community and local community colleges. The event will focus on three main themes: development of new sensor systems that use existing technologies in novel ways; new data storage or transmission solutions; and community initiatives to facilitate continued creation and sharing of new technologies. Sessions will foster knowledge exchange, build networks, and develop community resources focused on innovative DIY research solutions, and a hybrid virtual option will be offered for oral presentations to broaden participation.
The Soil Spectroscopy for Global Good (SS4GG) initiative is a collaborative network of hundreds of soil scientists and others focused on using soil spectroscopy as a means to generate high-quality soil data at significantly reduced costs. It was created in 2020 by the Woodwell Climate Research Center, the University of Florida, and the OpenGeoHub Foundation (the Netherlands) with support from many national and international institutions and researchers. SS4GG created and supports the Open Soil Spectral Library (OSSL), an open source of soil spectroscopy data, and a broad community of practitioners uses the library and collaborates on related science. This award will extend the activities of the SS4GG initiative with a focus on training and further engagement with the soil science community. The project team will continue to add data sets and new models to the OSSL, as well as engage with the soil science community by attending international conferences and providing a training workshop. The funds will also support hosting a visiting soil biogeochemist at the Woodwell Climate campus—Dr. Raj Setia from the Punjab Remote Sensing Center.
Sequestering, or capturing carbon in soils has a high potential to mitigate climate change. It is challenging to specifically predict how successful carbon sequestration may be, as current models used to evaluate agronomic management oversimplify soil microbial properties. This project will test for the key pathways of carbon transformations using soil samples taken under cover crops from a long-term study site. The team will quantify the chemical diversity of carbon substrates that microbes in the soil take up, and use data mining to predict the impacts of that diversity on soil carbon sequestration and nutrient cycling. The research outcomes will also lay a foundation for future collaborative research within the Department of Energy scientific community, and the soil health research community more broadly.
The protection, improved management, and restoration of forests are key nature-based solutions to the climate crisis, yet implementation and maintenance of these forest-based solutions requires sustainable and substantial financing. The voluntary carbon market (VCM) has the potential to deliver the necessary level of financing; however, a significant gap exists between its potential and actual performance. Improving the accuracy of forest carbon monitoring is crucial for the VCM to deliver effective, meaningful climate change mitigation. This project will enhance the credibility and effectiveness of forest carbon markets by evaluating new remote sensing methods for measuring forest carbon and showing that these methods provide more robust data than the conventional approach. Research findings could lead to updated global standards and policies for issuing carbon credits, which would increase market confidence and promote sustainable forest management.
In recent decades, extreme drought events have increased forest flammability, fire severity, and the likelihood of fire escaping and spreading into adjacent forests and working lands, as illustrated by the wildfires seen throughout Amazonia during the 2023-24 drought. The project team will explore the potential of using river stage (water level) data as a proxy for landscape dryness, to ultimately reveal the short-term risk of wildfires spreading into forests. If confirmed, this innovative hypothesis could provide the scientific basis for developing new metrics of river stage to improve early-warning systems that forecast high fire risk days to weeks in advance. These improvements would create benefits not only for tropical forest protection, but also for biodiversity, greenhouse gas emissions, and human health.