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.

What are ice wedges, and why are they important to climate change?

“I think ice wedges are what make permafrost interesting,” says Dr. Anna Liljedahl. 

Liljedahl works on Woodwell Climate’s Arctic team as an Associate Scientist. She aims to understand how climate change is affecting water storage and movement. Much of her recent work focuses on ice wedges and how they are reacting to warming Arctic summers. But just what are ice wedges anyway?

Ice wedges are one of the three main features of the Arctic’s land surface. Permafrost, ground that remains below 0˚C for at least two consecutive summers, lies under a thinner layer of thawing and refreezing soil, called the active layer. When permafrost cracks during cold winter days, snowmelt and runoff water seep into the empty space. These eventually freeze and create a wedge-shaped spear of ice that extends vertically down into the permafrost.

Ice wedges actively re-shape the tundra. When they freeze, they grow and expand outward, pushing against the bordering permafrost and active layer. With nowhere else to go, permafrost and soil push upwards, and ridges form on the surface of the tundra. The ridges interlock and form distinct shapes, referred to as ice-wedge polygons. 

The ridged borders of ice-wedge polygons form directly above expanding ice wedges below the surface, and are therefore more elevated. The lower internal portion of the polygon allows pools of water from runoff and snowmelt to form atop the active layer. These polygons are visible all the way from space. 

Thanks to satellite imagery, scientists like Liljedahl are able to monitor ice-wedge polygons remotely. Satellite images date back to the mid-20th century and can be used to observe changes in the landscape overtime. 

During unusually warm summers, the tops of ice wedges can melt, which removes underlying support of the ground surface, causing slumps along the borders of ice-wedge polygons. These leveling borders form channels that siphon the water from pools in the centers of neighboring polygons. The resulting runoff streams can drain small pools and even larger lakes that took thousands of years to form. 

With the progression of climate change, these drainage systems have become more common. Liljedahl refers to them in the title of her manuscript, just published in the July issue of Nature Water, “The Capillaries of the Arctic Tundra.”

The increase in creation of new “capillaries” in the Arctic is impacting not only the topographical landscape of the region, but also the livelihoods of all beings that find their home there. 

At first, the melt of these ice wedges can spark an uptick in the variation of vegetation due to moisture along the sides of the channel. This, however, is temporary. When the ice wedges stabilize again in the winter, this variation decreases once more. 

Aquatic mosses— one of the most productive vegetal forms in the Arctic, equivalent in productivity to Arctic shrubs— inhabit pools formed alongside the edges of ice-wedge polygons. They lose their homes when bodies of water drain away. Major vegetation changes can alter carbon storage, availability, and emissions across the tundra.

 Humans are also impacted. Homes become too dangerous to live in as the ground supporting vital infrastructure collapses. Roads connecting communities to important resources are destroyed by subsiding ground. 

Despite their widespread impact, ice wedges are often overlooked in Arctic climate models. Historically, their inclusion “costs too much computer time,” Liljedahl says, to factor in. Many climate models take a holistic approach to the Arctic landscape, as opposed to focusing on smaller details. 

To remedy this, Liljedahl suggests utilization of developing technology such as Artificial Intelligence (AI). Classifying the Arctic landscape by type, for example, into high-center polygons, low-center polygons, and capillary networks, would factor ice wedge change into climate models. As AI advances and becomes a more common research tool, it could help decrease the human computing time that Liljedahl identifies as a barrier. 

Arctic research is likely to change drastically in the coming years. With new technologies, and as we learn more about the Arctic landscape, research models will likely become more inclusive of the varied features within it, and much more accurate. 

“There are exciting years ahead,” Liljedahl says, “I think we’re going to see some cool stuff coming out [of tundra research] in the next five to ten years.”

We can all agree 2023 was a weird year for weather, right? The United States set a record for the number of billion dollar weather disasters. A major Amazon River tributary reached its lowest water levels in a century during extreme drought. Extreme rain in Libya caused two dams to break, destroying homes and killing over 4,000 people.

And then, of course, there was the heat. 2023 was the hottest year on record. Countries around the world saw heat records fall month after month. The Arctic was hot. The ocean was hot. And debates swirl on about whether we’ve already passed critical warming thresholds.

So how do we put 2023 in context of the greater trend of warming? Here’s what some of Woodwell Climate’s scientists have to say about last year’s record-breaking events.

Did the models predict this?

The dramatic scenes of heat and extreme weather last year prompted many to ask why temperatures had seemingly spiked way above the trend line. Was this unexpected? Was it out of the range of what scientists had modeled? Woodwell Senior Scientist, Dr. Jennifer Francis says not entirely.

“Almost exactly a year ago,” says Francis, “we had just come out of three years of La Niñas and we came close to breaking global temperature records then, even though La Niñas tend to be cooler than neutral or El Niño years. And then along came the strong El Niño of 2023.”

El Niño and La Niña are two extremes of a natural phenomenon that impacts weather patterns across the Pacific, and around the world. In an El Niño year, the prevailing trade winds that normally push warmer waters into the western tropical Pacific—allowing cooler water to well up along the western coast of the Americas—are reversed, resulting in hotter ocean surface temperatures in the eastern equatorial Pacific. When the ocean is hotter than the air above it, that heat is released into the atmosphere, often making El Niño years record breaking ones for global temperatures. 

“Last year’s spike looks a lot like the last big El Niño event in 2015-2016. It’s just that now the whole system is warmer. So to me, it wasn’t at all a surprise that we smashed the global temperature record in 2023,” says Francis.

The spike put global temperatures far above the average of climate model simulations, but that doesn’t mean the models didn’t account for it. Risk Program Associate Director, Dr. Zach Zobel, says that averages tend to smooth out natural year-to-year fluctuations, when in fact the upper and lower ranges of model predictions do encompass temperatures like the ones seen in 2023.

“It was well within the margin of error that you would expect for natural variations,” says Zobel.

How does ocean heat impact the climate?

One element of last year’s heat, one that wasn’t necessarily forecasted, was the simultaneous appearance of several ocean heat waves around the globe. The ocean absorbs the vast majority of heat trapped by greenhouse gasses, and that heat can be released under the right conditions. El Niño is one example, but in 2023 it coincided with other not-so-natural marine heat waves across the world.

“In pretty much every single ocean right now there are heat waves happening, which is something quite new,” says Francis.

A couple of dynamics could be driving this. One possibility is that, after three years of La Niñas, in which equatorial Pacific ocean temperatures were generally cooler than the air, the ocean simply absorbed a lot of heat, which was then primed to be released in an El Niño year. Another, Zobel suggests, could be recent shipping laws that required shipping vessels to eliminate sulfate emissions by 2023. Sulfates are a pollutant that may have been helping bounce back solar radiation, hiding the true extent of warming.

“Usually when there’s an El Niño, the eastern tropical Pacific is very warm, but it doesn’t actually drive up ocean temperatures everywhere,” says Zobel. “That was the biggest surprise to me: how warm the northern hemisphere of the Atlantic and Pacific were for most of last year and into 2024.” 

Ocean heat waves are typically long-lived phenomena, lasting many months, and so can be a useful tool for meteorologists looking to predict 2024’s extreme weather events.

“The good news is that it provides some kind of long-term predictability about weather patterns in the upcoming year,” says Francis. “The bad news is that they tend to be unusual weather patterns, because those ocean heat waves aren’t usually there.”

Will next year be hotter?

So are we in for another, hotter year after this one? Risk Program Director Dr. Christopher Schwalm says it’s likely.

“Warming predictions for 2024 from leading scientists all forecast a higher level of warming this year than last year,” says Schwalm. 

Already, March 2024, was the 10th month in a row to break temperature records. Zobel says it’s typical for the year following an El Niño peak to maintain high temperatures.

“Because the ocean spent a good amount of the year last year warmer than average, that energy is typically dispersed throughout the globe in the following year,” says Zobel. “So even though the tropical Pacific might return to normal, that energy is still in the system.”

However, atmospheric scientists are already seeing signs that El Niño is slowing down and flipping to its counterpart, La Niña, adding another layer of complexity to predictions for 2024. 

“The 2024 hurricane season is a large concern,” says Zobel. “La Niña is a lot more conducive to tropical cyclone development. If we combine above average numbers with the amount of energy that storms have to feed on, it’ll be a shock to the system.”

What does this mean for 1.5?

In the discussions around 2023’s temperatures, one number dominates the conversation: 1.5 degrees C. This is the amount of warming countries around the world agreed to try to avoid surpassing, in accordance with the United Nations’ 2015 Paris Climate Agreement. Estimates from Berkeley Earth say that 2023 may have been the first year spent above that threshold. 

This assertion may take several years to verify— one year spent physically above 1.5 degrees of warming does not indicate the UN threshold has been permanently passed. What scientists are looking for is a clear average trend line rising above 1.5 degrees C without coming back down, and for that you need several years of data. That, regrettably, creates a lag time between climate impacts and updating climate policy. But, for many, the debate around the arbitrary 1.5 degree goal has become a distraction. Schwalm says scientists and policy-makers should be focusing on urgently combating climate change whatever the numbers say.

“We are already living in a post-Paris Agreement reality,” says Schwalm. “The sooner we admit that and reimagine climate policy, the better.”

“Actual real world impacts are going to be there, whether we’re at 1.48 or 1.52,” says Zobel.

And Francis agrees. “There are so many indicators telling us that big changes are underfoot, that we are experiencing major climate change, but reaching 1.5 isn’t going to all of a sudden make those things worse. It’s just one more reminder we’re still on the wrong track and we’d better hurry up and do something.”

Freeze on Russian collaboration disrupts urgently needed permafrost data flow

two researchers hold a ladder steady for a third researcher who is working with equipment at the top of a mid-size tower in Alaska

Warming temperatures in the Arctic are accelerating the thaw of carbon-rich permafrost and threatening to add massive amounts of carbon dioxide and methane to an atmosphere already overheating from the buildup of anthropogenic greenhouse gas emissions.

More than half that permafrost lies beneath remote Russian soil, where scientists have long worked in an international research community that freely shared its field stations, climate sensors and data sets to better understand the rapidly changing polar region’s planetary impacts.

Researchers are especially eager to know when a dangerous tipping point may be reached that would trigger the release of vast amounts of greenhouse gases stored in frozen soils.

But then came the Russian invasion of Ukraine on Feb. 24, 2022, and all that cooperation came to a halt, part of the fallout of Western sanctions on Russia. Since then, international researchers outside Russia have applied creative workarounds in order to continue their research, but problems remain.

Read more on Mongabay.

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.

Read more on Permafrost Pathways.

COP 28, the annual meeting of United Nations delegates to set goals and report progress on addressing climate change, closed last week in Dubai after a two-week rollercoaster that was both promising and discouraging. When weak draft language surfaced, just a few days before negotiations were set to close, shying away from any clear call to eliminate fossil fuels, the outlook was not optimistic. But nearly overnight, representatives managed to arrive at a deal. For the first time in 28 years of negotiations, the final agreement included direct reference to the need to “transition away from fossil fuels in energy systems, in a just, orderly, and equitable manner.”

The language is not as strong as many hoped, but it still represents a historic step forward, and came as a positive surprise after controversy surrounding the oil interests of the host country.

“We’ve known from COP number one that fossil fuels are a major cause of the problem with respect to climate change, but the reality is that it wasn’t until COP28 that the words ‘fossil fuels’ were actually recognized in the agreement,” says Woodwell Climate CEO and President, Dr. Max Holmes. “It’s really late in the game, but I think it’s important that this was finally recognized. Yet words are not actions, and much more needs to be done.”

International agreements were also made to reduce methane emissions generated by fossil fuel extraction and triple renewable energy by 2030, as well as enact the agreed-upon Loss and Damage fund created last year, which will use contributions from wealthier countries to support those suffering the worst climate-related impacts.

Progress also occurred on many smaller stages at COP28. Woodwell Climate had a strong presence, sending 16 scientists and staff to advocate on a variety of issues, including increased ambition in curbing emissions, funding for adaptation measures, action around permafrost and tropical forest issues, and improvements in transparency around carbon markets. Here are some of our key highlights and takeaways from COP28.

Protecting tropical forests

One core tenet of the Center’s research is the value of protecting and restoring natural ecosystems for both their intrinsic and climate importance. A check-in on pledges to end deforestation by 2030 shows they are mostly going unmet, but the final agreement did include language that acknowledged the importance of “protecting, conserving, and restoring forests”, which Woodwell Carbon Program Director, Dr. Wayne Walker, notes was another significant inclusion this year.

“Nature has a tremendous role to play and that’s really what this section is trying to emphasize: the importance of bringing nature to bear in the mitigation conversation alongside transitioning away from fossil fuels,” said Dr. Walker.

Woodwell Climate used this year’s COP to build and deepen partnerships that advance efforts to protect the carbon-storage powerhouses that are tropical forests. For example, Woodwell Climate hosted a discussion with Health in Harmony and Pawanka Fund about the power of  investing in Indigenous-led climate solutions. 

“Woodwell has been partnering increasingly with organizations like Health in Harmony and Pawanka fund, who are really strong advocates of Indigenous self-determination”, says Dr. Walker. “Pawanka Fund is a really great example of an Indigenous-led fund that provides direct support to Indigenous initiatives focused on promoting and protecting traditional knowledge, well-being, rights, and self-determined solutions to a whole host of issues. Organizations like [them] are critical to properly compensating Indigenous peoples for their contributions to climate change mitigation.”

Climate risk and carbon markets

On December 5, Woodwell Climate announced the release of a new report in partnership with the Ministry of the Environment and Sustainable Development (MEDD) of the Democratic Republic of Congo (DRC). The report was the culmination of a multi-year collaboration to generate a localized, customized, cost-free climate risk assessment for the country that details both challenges and solutions. 

“This report was two years in the making, and was only possible because of close collaboration between Woodwell scientists, government leaders in the DRC, and experts at the University of Kinshasa,” says Woodwell Chief of Government Relations. “Our goal was to provide an actionable risk assessment that could directly inform Congolese policymaking. We developed that, but our partnership also identified the need for increased scientific and technical capacity, as well as a new framework for carbon market regulation.” 

The assessment identified improved carbon credit integrity as a mechanism to fund climate adaptation projects in the DRC and support forest preservation as a critical natural climate solution.

“We and others think carbon markets will have tremendous potential for bringing large amounts of capital to the ground to the people into the places responsible for implementing natural climate solutions,” says Dr. Walker. “But there’s no question that right now, carbon markets are plagued with all sorts of problems. There’s a lot of work to be done if they’re to function properly, sustainably, equitably.”

Pushing for permafrost accountability

Unfortunately, neither the Arctic nor permafrost were mentioned in the COP28 final agreement and Woodwell Climate Arctic Program Director, Dr. Sue Natali, says it is crucial that changes.

“Permafrost emissions can consume about 20% of our remaining carbon budget to avoid 1.5 C, and there will be much greater emissions from permafrost if we overshoot 1.5 C,” says Dr. Natali.

Dr. Natali spoke at several events in the Woodwell Climate space as well as in the Cryosphere Pavilion during Permafrost Day. Top of mind was not only the need to incorporate permafrost emissions into global carbon budgets, but also the need for Loss and Damage funding to extend to Northern communities being displaced by thawing and eroding permafrost. Discussions around Loss and Damage funding are currently focused on supporting countries in the global south, but many Arctic communities are grappling with decisions about relocation and adaptation, and have been for decades.

“These communities who already have very limited land are losing it to permafrost thaw, wildfire, increased storm impacts. This has been going on for a really long time and they urgently need resources,” Dr. Natali said. 

Where the rubber meets the road

“These high-minded Nationally Determined Commitments are ambitious in their target setting, but the national level policy is where they become reality,” says McGlinchey. Emphasizing that we will have to wait and see how the promises made at this year’s COP are enacted by different nations. During the conference, the Woodwell Climate meeting space was visited by two US senators, Ed Markey of Massachusetts and Lisa Murkowski of Alaska, who showed interest in permafrost and other climate issues.

Looking towards COP29, which will be hosted in Azerbaijan, the hope is that ambition and national commitments will increase, because while progress was made in this year’s agreement, it was nowhere near big enough to limit warming to below 1.5 degrees celsius. With current warming at around 1.2 degrees, we will have to be swift and decisive.

“This past year was a remarkable one— the hottest on record. The impacts of climate change are here and are being felt by people here and around the world. And that adds urgency,” says Dr. Holmes.

For the full debrief of COP28, you can watch our Webinar here.

Located in Eastern Alaska, the Yukon Flats National Wildlife Refuge is larger than many U.S. states. It’s a roadless landscape of rocky mountain outcroppings, flat meadows, treeless tundra, and dense spruce forests, bisected by the Yukon River and dotted with thousands of lakes and wetlands. Several Alaska Native communities call the refuge home and subsist off of its natural resources. This diverse, expansive wilderness is well adapted to fire, and it’s not uncommon to see pink fireweed blooms or young grass and seedlings sprouting from burn scars.

But the relationship between fire and land here—as in many places—has been changing as the climate warms. Yukon Flats sits atop ancient, ice-rich ground, called Yedoma permafrost, formed during the last ice age. Thawing Yedoma is a significant source of carbon dioxide and methane emissions to the atmosphere. Fire, made more intense and frequent by climate change, threatens to accelerate that thaw. In an effort to preserve carbon stores, the U.S. Fish and Wildlife Service recently dedicated 1.6 million acres of the Yukon Flats refuge to piloting a new firefighting regime, one designed to protect carbon, in addition to human lives and property.

Science builds the case for policy change

This decision was, in part, influenced by research led by Dr. Carly Phillips, during her time as a research scientist at the Union of Concerned Scientists, alongside Woodwell Climate Senior Science Policy Advisor, Dr. Peter Frumhoff, and Associate Scientist, Dr. Brendan Rogers. In a 2022 paper in Science Advances, the group quantified the threat boreal forest fires pose to climate goals. Wildfires in boreal North America alone could, by mid-century, use up 3% of remaining global carbon dioxide emissions associated with keeping temperatures below the Paris Agreement’s 1.5°C limit. This is a conservative estimate—the authors suggest the true numbers could be even larger as the accelerating effect of fires on permafrost thaw, and the release of other greenhouse gasses, were not included in the analysis. 

The study also examined the cost-effectiveness of combatting those fires as a potential climate solution. Molly Elder, an economics and public policy Ph.D. candidate at Tufts, performed an analysis of data from across Alaska’s fire management zones and found that actively suppressing boreal fires could cost less than 13 dollars per ton of carbon dioxide emissions avoided—putting it on par with other carbon mitigation solutions like onshore wind or utility-scale solar. 

“The work we did in this project proved and quantified what the management community already knew, which is that management is effective at reducing burned area when fires are actively suppressed,” says Elder.

Combating boreal fires could provide much needed mitigation, and at a low cost, but there are some logistical obstacles between the hypothetical model and actual implementation. Typically, in Alaska, boreal forest fires are left to burn unless they present a risk to human life or property. This is partly because these forests are fire-adapted, but also partly due to the sheer vastness of boreal wilderness. With limited resources, it is not always practical or possible to track down and put out a fire, especially in a place without roads like Yukon Flats. Firefighters are already stretched thin with lengthening and increasingly high-intensity fire seasons.

So the research group worked with the fire management community in Alaska, facilitated by the Alaska Fire Science Consortium, to better understand the needs of firefighters and demonstrate the co-benefits of fire suppression in addition to preserving carbon. 

“Many of the fire managers expressed how stretched their resources already were and resistance to the idea that yet another mandate would be added to their plate,” says Dr. Phillips. “However, after discussing the implications of our research, and the ambition that additional funding would come with any mandate, we got more buy-in.”

Fire suppression: It’s not a dirty word

The other concern managers raised was whether fire suppression would ultimately be successful in achieving their goals. Historically, fire suppression efforts in the US have been counterproductive to protecting forests.

In the late 1800s, lack of understanding of the ways Indigenous communities in Western states have used fire to maintain healthy forests resulted in decades of near-total suppression of fire in the region. In many western US forests, (adapted to what Dr. Rogers calls “high-frequency, low-intensity” fire) suppression allowed highly flammable, dry vegetation—which would normally be periodically burned away—to build up. When fires did spark, they were then capable of growing to a size and intensity that could damage, rather than activate, the forest. 

But in boreal Alaska and Canada, it’s just the opposite. The spruce-dominated forests are adapted to high-intensity fires that only return every hundred or so years. As climate change speeds up the return of fires with hotter and drier conditions, boreal forests have begun to suffer major losses. 

“The frequency of boreal fires, ultimately, is increasing. In many places we’re seeing more reburning and larger burned areas,” says Dr. Rogers. “Climate change and human actions are shifting that fire regime out of its historical range into this new realm. So the whole idea of fire suppression in the boreal is to keep fires closer to historical levels, to which the systems and fauna are adapted. Suppression can help delay permafrost degradation, limiting carbon emissions and buying us time to reach our climate targets.” 

Past missteps with fire suppression have made fire managers cautious, though. Lisa Saperstein, Regional Fire Ecologist with U.S. Fish and Wildlife, notes that, with limited resources, priorities in intense fire seasons will have to shift to protecting human settlements over carbon and permafrost. But, given the co-benefits of keeping fire activity to historic levels—and the urgency of reigning in emissions in any way we can—managers in Yukon Flats were willing to try.

“This type of shift in values is always difficult, especially when the outcome is uncertain. Support from leaders of fire management organizations, in addition to land managers, has been a key factor in this effort moving forward,” says Saperstein. 

If a fire starts in the woods, how do you fight it?

This change in tactics won’t mean that every fire that ignites will be put out—both impractical and unhelpful from an ecological perspective—but it will mean more aggressively targeting fires when they arise. Since the 1980s, when fire was detected in Yukon Flats, it would be monitored by the Alaska Fire Service, but not suppressed, except when presenting a threat to human communities.

“This pilot project is a new twist to a long-standing partnership between the U.S. Fish and Wildlife Service and Alaska Fire Service. For select areas of the Refuge, now if a fire start is detected, we ask the Alaska Fire Service to only send a crew if they are confident in 100% containment within three days,” says Yukon Flats Refuge Manager, Jimmy Fox.

The suppression teams will target fires that they judge as “quick fixes”, curbing the potential for them to grow into large, stand-replacing sized blazes. If a fire becomes too big to fight quickly, the teams revert to the old tactic of simply monitoring.

“If a crew is deployed, we ask that they cease suppression and return to base after three days, regardless of containment status,” says Fox. “This request is grounded in concern for the Alaska Fire Service having resources available if communities become threatened from other fires.”

Fox says refuge management and Alaska Fire Service members will stay flexible as the pilot project unfolds so they can respond to changing conditions.

“In conservation, we tend to focus on the technical aspects of a challenge and avoid the difficulties that come with asking ourselves to adapt,” says Fox. “This pilot project is both adaptive and technical. It has required me to stay curious and listen. It has required me to learn new information, and share it in a way that is comprehensible. It’s required being comfortable with uncertainty, and yet standing in purpose. It has been a learning journey so far, and will continue to be.”

Putting models to the test

On the research side, the team at Woodwell Climate hopes this new strategy will present an opportunity to study the practical implementation of fire suppression as a climate solution.

“This is the proof of concept,” says Dr. Frumhoff. “This is the opportunity to really see in a rigorous way whether we can apply this solution at a meaningful scale and gain meaningful carbon benefits with relatively modest cost. And it’s directly traceable to the conversations that the research team had with fire managers.”

The 1.6 million acres slated for fire suppression are small compared to the 8.6 million that comprise the entire refuge, or the 5.6 billion acres of permafrost in the northern hemisphere, but it’s a very important start. Research and analysis of the effectiveness of this solution could aid its expansion to other regions of the Arctic.

“It’s a big moment, because, while it’s obviously a relatively small area compared to all of Alaska, 1.6 million acres is still a lot of land,” says Dr. Rogers. “We’re hoping that it’s a jumping off point and can translate to other refuges and other agencies with the addition of proper funding and staffing.”

And each summer, the case for protecting permafrost and boreal carbon, while working to  dramatically reduce emissions from fossil fuels, continues to grow. 

“Every year that goes by, as fires intensify and climate change gets worse, this message might resonate just a little more, ” says Dr. Rogers. “Because it’s a problem that’s not going away if we do nothing about it. And we can do something about it.”

June 29, 2022— When Susan Tessier and her husband, Tim, went out for the day, they had a lake on their Native allotment. When they came back, It was gone. 

My husband Tim and I left home in the morning and when we came back around 8:00 in the evening the whole lake had drained,” she writes in a post on the Local Environmental Observation Network site—a community science website where observers can report unusual changes in their local environment. “There was a hole that had blown out and it had drained into the ocean… It looked like it was blown up with dynamite.”

Water is the ecosystem engineer in the Arctic. The lowland tundra landscape is a network of lakes and streams, mosaicked across an expanse of frozen ground riddled with wedges of ice. The freezing, thawing, moving, eroding dynamics of these features shape the larger landscape, and determine the habitats of fish, birds, plants, mammals—and, of course people—living in the Arctic. 

Abrupt lake drainage, like Tessier described, is just one way that changes in water and ice can influence the landscape, but a recent review paper conducted by University of Florida Postdoctoral Associate, Dr. Elizabeth Webb, and Woodwell Climate Associate Scientist, Dr. Anna Liljedahl, indicates events like this may become more common as the climate warms— overtaking lake expansion and slowly drying out the Arctic tundra.

Evidence of lake drainage across the literature

This new paper comes on the heels of a 2022 study that Drs. Webb and Liljedahl also authored, which came to the same conclusion: despite the processes of lake expansion and drainage continuing simultaneously across the Arctic, net lake area is trending downward. The Arctic is getting dryer.

The review complements the strengths of the previous study, compensating for some of the limitations of using geographically coarse remote sensing data. Synthesizing data from 139 sites across the Arctic, pulled from 57 different studies, Drs. Webb and Liljedahl were able to corroborate their own past findings. 

“Lake size can vary from one season to the next in response to factors like precipitation or evaporation, so if you’re only looking at a limited set of remote sensing images, that can influence a trend analysis,” explains Dr. Webb. “It’s actually really exciting from a scientific rigor perspective to have two completely different remote sensing methods showing the same result.”

The review also adds weight to the idea that permafrost thaw is the primary driver in the loss of Arctic lakes. A large portion of Arctic soil is ice-rich, perennially frozen ground called permafrost, and as the climate heats up, it has begun to thaw and destabilize. That thawing can both create new ponds, and help drain them. The review indicates that decreases in size and number of Arctic lakes are more prevalent than expected, dominating the dynamic in some areas.

This contradicts another leading theory that changes in precipitation and evaporation rates— called the “water balance hypothesis” — are driving changes in lake area. Prior to Drs. Webb and Liljedahl’s investigations, the prevailing thought was that lake creation would outpace drainage rates, for at least the next several decades. 

Climate Change is Opening Drainage Channels in the Permafrost

It works like this: most Arctic lakes form when wedges of ice in permafrost melt, leaving behind a depression that fills with water. The water absorbs and holds more heat, slowly thawing and eroding surrounding permafrost, growing from puddle to pond to lake over the years.

Drainage can happen in one of two ways. The first is vertically, which occurs when the permafrost beneath the lake thaws down to the unfrozen ground beneath, allowing the water to seep out the bottom. This can take hundreds or thousands of years, depending on how deep the permafrost is.

The second way is horizontally, through what Dr. Liljedahl calls “capillaries”. Ice wedges are common across the Arctic, connected by an underground network of ice that pushes the soil above them upwards as they grow, creating ridges that impede water flow. But when the tops of these wedges melt, the ridged ground above them subsides, forming narrow channels between lakes and ponds. When an expanding lake meets one of these capillary channels, the lake can drain in a matter of hours, as if the plug has been pulled on a bathtub drain.

“The formation of lateral drainage channels can interrupt this lake expansion process at any time, and I think that’s what’s making it override expansion and cause the net drying effect,” Dr. Liljedahl says. “The lake that took millenia to grow can be gone in a couple of hours.

Fewer Arctic Lakes Leave Communities in the Lurch

So what does an Arctic with fewer lakes mean? In terms of carbon, the picture isn’t clear. Since lake expansion— a common source of methane emissions— and lake drainage are happening concurrently, the net effect is not easy to discern. 

“With lake drainage, it’s much less clear what the carbon consequences are. The current thinking is that lake expansion releases orders of magnitude more carbon than lake drainage, but because it’s complicated, we’re not quite sure,” says Dr. Webb.  “It’s definitely an open research question.”

Dr. Liljedahl notes that there is also documentation of permafrost recovering and re-growing in drained lake beds. “Over decades, they could develop new ice-wedges and vegetation on the surface. Lake beds could experience net carbon accumulation for at least a couple of decades after drainage,” Dr. Liljedahl says.

However, the ecological consequences of fewer Arctic lakes are more certain. Fish and other aquatic species will have the size of their habitat reduced and their freedom of migration restricted, as lakes drain and connecting streams dry up. Species that feed on fish or rely on wetland vegetation, like muskrats, will also be impacted.

Small lakes are an important source of freshwater for Arctic communities. Tessier wrote in her post about the lake drainage she witnessed, “We are sad to lose the lake because in winter, after it froze up, we used to go cut ice chunks for drinking water. It has really clear water. If we get enough snow we can use snow water instead, but it is not as good.”

As more lakes drain, clean freshwater could become harder to access. Combined with the destabilization of the ground itself as permafrost thaws, Arctic communities are facing massive changes.

Dr. Liljedahl hopes that refining our understanding of water dynamics in the Arctic will aid adaptation measures. She has been awarded a three year NSF grant to continue studying the ice wedge capillary network and its role in the Arctic hydrological system. She’ll use remote sensing to quantify the distribution of the ice-wedges contributing to increased drainage. She also plans to pull data from field measurements to figure out how permanent the capillaries are, since vegetation feedback loops could help permafrost recover and return the surface to its original elevation. 

“We have more to do before we can feel like the models are representing a realistic scenario. We need to better understand what is happening at the sub-meter scale with water, because the presence or absence of surface water will have a major impact on how the landscape evolves,” Dr. Liljedahl says.