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.

Climate Impacts on Boreal Fire

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.

Climate conditions

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.

Fuel

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.

Ignition

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.

Fire Management as a Climate Solution

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.

Air quality monitoring to machine learning: Fund for Climate Solutions awards six new grants

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.

Arctic wildfire pollutants: Towards improving emissions estimates and developing tribally-led monitoring

Lead: Scott Zolkos
Collaborators: Brendan Rogers, Sue Natali, Kyle Arndt, Elise Sunderland (Harvard University)

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.

Workshop: Innovative sensors and applications in environmental research

Lead: Kathleen Savage
Collaborators: Zoë Dietrich, Marcia Macedo

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.

Soil Spectroscopy for Global Good network

Lead: José Lucas Safanelli
Collaborators: Jonathan Sanderman

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.

Pathways of carbon metabolism under cover crops

Lead: Taniya RoyChowdhury
Collaborator: Jonathan Sanderman

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.

Bringing confidence to carbon markets through improved monitoring

Lead: Seth Gorelik
Collaborator: Wayne Walker

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.

Applying machine learning models to link river hydrology and fire risk forecasting in the Amazon

Lead: Andrea D. de Almeida Castanho
Collaborators: Michael Coe, Marcia Macedo

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.

The way science is funded is hampering Earth System Models and may be skewing important climate predictions, according to a comment published in Nature Climate Change by Permafrost Pathways scientists at Woodwell Climate Research Center and an international team of modeling experts.

Emissions from thawing permafrost, frozen ground in the North that contains twice as much carbon as the atmosphere does and is thawing due to human-caused climate warming, are one of the largest uncertainties in future climate projections. But accurate representation of permafrost dynamics are missing from the major models that project future carbon emissions.

Making maps is a method of discovery

“But Google Maps exists. Haven’t all the maps been made already?”

Fiske and Shintani have heard it before: the idea that “everything has already been mapped.” Why should we create new maps of familiar places?

In a world beset by hundreds of transformative forces, of which climate change is one, Shintani responds that cartography is just as important now, if not more important than ever.

“The world is constantly changing,” says Shintani. “If it weren’t, we wouldn’t spend billions of dollars to capture satellite imagery every minute of the day. Political boundaries change every year, glaciers disappear, wildfires break out and alter the landscape, and we have to map the physical and social phenomena to understand that changing world.”

The act of creating a map can also be a method of revealing something new from existing data, which is why cartography plays a central role in research at Woodwell Climate.

Fiske and Shintani field frequent requests from scientists for maps to accompany research papers. According to Fiske, “sometimes the data for that is readily available, but sometimes it takes an entire geospatial analysis to derive what you need to make the map. And you won’t really know until you start iterating.” Often, viewing data on a map will inspire new scientific questions for researchers to chase down. The act of creating maps is not just an end product, it can be a critical step in the scientific process.

Cartography requires a little bit of everything

In their time at the Center, Fiske and Shintani have worked on maps detailing forest carbon in the United States, global drought forecasts, fire detections in the Amazon rainforest, and Arctic communities located on permafrost ground—they are no strangers to working across disciplines.

“Cartographers are generalists,” says Shintani. “We have to know a little bit about a lot of things, which actually benefits us as climate communicators, since the maps we’re making aren’t meant to inform other expert climate scientists, they are trying to convey information to everyone else.”

“Cartography isn’t really one profession,” Fiske clarifies. “It’s a collection of professions.”

A modern cartographer, according to Fiske, is a data analyst, a statistician, a designer, a programmer, a storyteller, and an artist all rolled into one. Skills from each profession, and a healthy curiosity about a hundred other topics, are required in order to create maps that are informative, attention-grabbing, and intuitive to read. Fiske entered into cartography through the world of computer coding, discovering an affinity for programming in his high school’s computer lab. He picked up the other skills later, with guidance from mentors, learning first to apply coding to geospatial data, and then how to display that data visually, and even make it beautiful.

Shintani’s entryway into cartography was through science. She had intended to study the physical geography of rivers, when a class on cartography changed her direction.

“With maps, I could organize everything in a way that made sense to me—because the world is so often organized in ways that don’t make sense—and I could make them beautiful,” says Shintani. “It was the first time I felt like I was really good at something.”

Fiske and Shintani’s cartographic talents eventually brought them both to Woodwell Climate, where their knowledge of various fields has helped them solve research questions and communicate new findings to the public.

“The day-to-day involves bringing together datasets, developing a clear story, making it look intuitive through design, taking the experts’ thoughts and data and making it a little more tangible for folks,” says Shintani.

To map something is to understand it

In another era, a cartographer might also have been somewhat of an adventurer—conducting expeditions to map hills and valleys, using mathematical conversions to capture the detailed curves of a coastline in a meticulously hand-drawn document. These days, cartography has much more to do with sitting behind a computer, manipulating massive datasets created by satellite observation and tweaking color pallets and font sizes using a variety of software.

The proliferation of satellite data has made the process of map-making much quicker and more accessible—no longer requiring long expeditions just to gather information on topography or ground cover. It’s allowed a shortcut to understanding the shape of places you’ve never been. A shortcut, Fiske says, but not a replacement.

“I would never have been able to make that map,” says Fiske, referring to the map of Alaskan topography that Howard and Woods brought to AFE, which earned him two awards from the Esri User Conference earlier this year. “If I hadn’t been to Alaska, seen it from an airplane, looked at those mountains, and seen what it looks like between the green valleys and the white glaciers.”

Travel is something Fiske believes should remain a part of the cartographer’s toolkit whenever possible, because a thorough understanding of a place is critical to being able to map it. Things like the natural colors of the landscape at different times of year, the true scale of glaciers when you are standing beneath them, the shape of a slumping and eroding hillside, give a fuller picture of the reality on the ground.

“A good map is a close connection to reality,” says Fiske. The closer to reality a map is, the more intuitive it is to orient yourself on it, understand the information the map is trying to convey. Fiske travels regularly, joining float trips with Science on the Fly or Permafrost Pathways’ visits to field sites and Alaska Native partner communities. He plays a role in the science, helping navigate and collect data, but values the experiences more for the insights he can use to inform future maps.

“If you’ve stood on the tundra,” he says. “Then you can make a better map of the tundra.”

A place in the world

A decade ago, Fiske recalls, he was helping a colleague map her work studying chimpanzees in the Congo Rainforest.

“We were going through and pulling coordinates out, sifting through notebooks that had obviously been sitting in the field for years, covered in water stains and mud.” They were overlaying documented nesting sites with data on forest type and at some point, Fiske turned around and realized she was in tears.

“Seeing it formulate on the screen, she was overcome with emotions,” says Fiske. “The map reflected what she had been carrying around in her mind the whole time.”

Maps, in Fiske’s experience, create instant—sometimes emotional—connections between people and places. They place individuals in the context of the wider world and put long-held ideas down on paper to be shared.

Which is why Fiske believes anyone can and should make maps. He has been helping the Permafrost Pathways team bring cartography into their work with Indigenous Arctic communities through a method called participatory mapping, which combines community input with technical expertise to create maps representing collective knowledge. Howard is also working with Fiske to create a digital version of his Alaskan topography map that incorporates the stories shared through the exercise at AFE.

Looking forward, Fiske wants to push his career more and more towards helping others create maps. Because everyone has stories to share about the places they know—whether they come from generations spent living on a landscape, or one lifetime’s work spent studying a single ecosystem.

“I want to help folks make maps,” says Fiske. “And tell their story.”