Woodwell Senior Scientist Dr. Rich Birdsey has contributed his decades-long expertise in forestry and climate issues to two new U.S.-based forest policy initiatives. Working on both the state and federal level, Dr. Birdsey is helping to expand the influence of science in policy planning.
Federal forest policy
On July 20, Woodwell Climate submitted a response to the U.S. Forest Service’s request for public input into how they can adapt current policies and develop new ones to support the conservation of the country’s forests and increase their resilience in the face of climate change. The push for new rulemaking within the agency is a direct response to President Biden’s recent executive order: Strengthening the Nation’s Forests, Communities, and Local Economies.
Protecting forests is a crucial emissions mitigation strategy both within the US and globally. Forests, particularly mature and old-growth stands, contain centuries-worth of stored carbon and continue to sequester more each year. Loss of these precious forests releases stored carbon and reduces future carbon sequestration.
In the public comment, Dr. Birdsey, who led the drafting effort, emphasizes the importance of protecting mature and old-growth forests, stating, “When climate benefits are explicitly considered, the research points strongly to letting these forests grow—protecting and expanding the massive portion of sequestered carbon they represent. One of the largest threats facing mature and old-growth forests in the US is logging, which is a threat that humans can reduce instantly, simply by changing policy.”
Forest protection on the state level
Dr. Birdsey has also been named a scientific expert on a committee charged with helping draft Massachusetts’ forest policies. A new state initiative, called “Forests as Climate Solutions” looks to expand existing forest conservation activities and develop new forest management guidelines that can help Massachusetts meet its climate goal of achieving net-zero greenhouse gas emissions by 2050. The science committee will be responsible for providing input into the state’s proposals and assessing their effectiveness as climate solutions.
“Forests have to be at the forefront of our climate strategy,” said Massachusetts Climate Chief Melissa Hoffer. “Trees can sequester carbon for centuries—we have a responsibility to use the best science to ensure that their potential for carbon sequestration and storage is reflected in our approach.
Dr. Birdsey’s hope is that the policies developed by the new initiative will help Massachusetts take full advantage of its naturally carbon-rich forests.
“Massachusetts forests have some of the highest carbon stocks in the Eastern U.S., and I hope that policies enacted through this initiative will strengthen protection of older forests and large trees and foster management of younger forests to attain old-growth characteristics, while maintaining the current level of timber supplies,” says Dr. Birdsey.
Both policy initiatives present an important opportunity to set forest management on the right track towards achieving emissions reductions in years to come.
“Massachusetts’ forests have the potential to accumulate and store enough additional carbon to compensate for as much as 10% of the State’s current emissions from burning fossil fuels,” says Dr. Birdsey. “With climate-smart forests, Massachusetts can be a national climate leader.”
Canada’s fire season has barely started and it’s already on track to break records. So far, NOAA has documented more than 2,000 wildfires that have resulted in the forced evacuation of over 100,000 people across Canada. The most recent bout of fires burning in Ontario and Quebec has sent smoke southward into the Eastern U.S., causing record levels of air pollution in New York and warnings against outside activity as far south as Virginia.
Only a little over a month into the wildfire season, fires have already burned 13 times more land area than the 110-year average for this time of year, and they show no sign of stopping, according to Canadian publication The Star. Indigenous communities, some of whom live year-round in remote bush cabins, have been particularly harmed by the blazes.
According to Woodwell Climate Senior Scientist Dr. Jennifer Francis, the phenomenon of winds pushing smoke down to the northeastern U.S. has been linked to rapid Arctic warming caused by climate change.
In the upper atmosphere, a fast wind current called the jet stream flows from west to east in undulating waves, caused by the interaction of air masses with different temperatures and pressures, particularly between the Arctic and temperate latitudes.
As global temperatures have risen, the Arctic has warmed two to four times faster than the average global rate. Dr. Francis stated in an interview in the Boston Globe that the lessening of the temperature differences between the middle latitudes and the Arctic has slowed down the jet stream, which results in a more frequent occurrence of a wavy path.
Another factor contributing to the widespread smoke is an ongoing oceanic heat wave in the North Pacific Ocean. The blob of much-above-normal sea water tends to create a northward bulge in the jet stream, which creates a pattern that sends cooler air down to California and warm air northward into central Canada—resulting in the persistent heat wave there in recent weeks. Farther east, the jet stream then bends southward and brings the wildfire smoke down to the Northeast.
“Big waves in the jet stream tend to hang around a long time, and so the weather that they create is going to be very persistent,” Dr. Francis said. “If you are in the part of the wave in the jet stream that creates heat and drought, then you can expect it to last a long time and raise the risk of wildfire.”
The wildfires are also decimating North American and Canadian boreal forests, the latter of which holds 12 percent of the “world’s land-based carbon reserves,” according to the Audubon Society<./a> And three quarters of Canada’s woodlands and forests are in the boreal zone according to the Canadian government.
“The surface vegetation and the soil can dry out pretty dramatically given the right weather conditions. For this fuel, as we call it in fire science, it often just takes one single ignition source to generate a large wildfire,” said Woodwell Climate Associate Scientist Dr. Brendan Rogers.
As the climate continues to warm, Dr. Rogers said the weather conditions that lead to fuel drying and out-of-control wildfires also increase. This creates a feedback loop. Heat waves caused by greenhouse gas emissions increase the prevalence of wildfires. The fires in turn destroy these natural carbon sinks and, in turn, speed up climate change.
While the ultimate solution to breaking this feedback loop lies in reducing emissions and curbing climate change, Dr. Rogers and other researchers at Woodwell Climate have conducted research into fire suppression strategies that could help prevent large boreal fires from spreading and help keep carbon in the ground.
A study conducted in collaboration with Woodwell and other institutions found that suppressing fires early may be a cost-effective way to carbon mitigation. Woodwell Climate’s efforts also include mapping fires, using geospatial data and models to estimate carbon emissions across large scales, and looking at the interplay between fires and logging.
“Reducing boreal forest fires to near-historic levels and keeping carbon in the ground will require substantial investments. Nevertheless, these funds pale in comparison to the costs countries will face to cope with the growing health consequences exacerbated by worsening air quality and more frequent and intense climate impacts expected if emissions continue to rise unabated. Increased resources, flexibility, and carbon-focused fire management can also ensure wildlife, tourism, jobs, and many other facets of our society can persevere in a warming world,” Dr. Rogers said.
On April 20, 2023, the U.S. Department of the Interior (DOI) and Department of Agriculture (USDA) released a first-of-its-kind inventory of the country’s mature and old-growth forests. The assessment responded directly to a 2022 executive order aimed at fostering healthy forests.
The inventory highlights the importance of forest health in building resilience to future climate-related disturbances like drought or fire, but it omits mention of the service that all forests, but particularly mature and old growth forests, provide in directly mitigating the country’s carbon emissions—a service that Woodwell Climate’s scientists have worked to measure and monitor for over three decades.
The inventory is a critical starting point, from which agencies like the U.S. Forest Service and the Bureau of Land Management will begin to make decisions about how public forests are managed going forward. Not acknowledging the critical carbon storage contribution of mature and old-growth forests runs the risk of de-prioritizing protection for the country’s oldest, most carbon-rich, and hardest to replace ecosystems.
Why protect mature and old-growth forests?
In short: carbon. While all forests sequester carbon as they grow, older and larger trees represent an existing store of carbon in their biomass and soil. Research by Woodwell Climate scientists on carbon stocks in a sample of federally managed U.S. forests found that while larger trees in mature stands constitute a small fraction of all trees, they store between 41 and 84 percent of the total carbon stock of all trees.
An analysis of mature and old growth forests across the country found that approximately 76 percent (20.8 million hectares) of these forests are unprotected from logging. This represents an amount of carbon roughly equivalent to 1 quarter of the US’s annual fossil fuel emissions.
Although younger forests grow faster proportionally, they are not adding as much carbon in a single year as older forests with large trees. Additionally, mature forests continue to pack away carbon year over year in their soils, which is largely protected from effects of disturbance. Cutting down a mature forest creates a “carbon debt” that can take decades—centuries in some cases—to recoup, and in the meantime those mature trees are no longer sequestering carbon each year.
“Forests are like naturally occurring factories, delivering to the planet the unique service of carbon sequestration. Trees of all sizes, but particularly large old trees, are the equivalent of warehouses where the goods produced—tons of carbon—are stored over time,” says Woodwell Climate Carbon Program Director, Dr. Wayne Walker. “Like any warehouse where valuable goods are stored, these natural carbon reserves deserve all the protection we can provide. Their loss could effectively bankrupt our efforts to avoid the worst impacts of climate change.”
Defining mature and old-growth forest
Protecting mature forests requires them to be identified and mapped, which was part of the impetus behind the government’s forest inventory. But what actually is a mature forest?
Definitions of “mature” and “old-growth” differ, with no one universally accepted definition. Refining scientific understanding of what constitutes a mature forest has implications for either expanding or reducing the area of forest considered for protection.
In one study of U.S. forest carbon stocks, Woodwell Climate researchers and collaborators outlined a measure of forest maturity based on both the age that the tree canopy in a forest becomes 100 percent closed, called “Culmination of Net Primary Productivity,” and tree diameter size. Across 11 U.S. forests analyzed, the age at which a forest is considered mature ranged from 35 years in Appalachian forests to 75 in Arizona. “Old-growth” represents a smaller subset of mature forests having older and larger trees.
The new inventory from the DOI and USDA uses a slightly narrower definition of maturity, wherein the lower bound occurs when regeneration has begun underneath the canopy. This results in a slightly smaller estimation of the amount of mature and old-growth forests in the US—yet still approximately 63 percent of the total area of federally managed forests.
Other definitions can be based on models that take into account measurements of forest structure like canopy height, canopy cover, and biomass. Another study, co-authored by Woodwell Climate Assistant Scientist, Dr. Brendan Rogers, used these features to determine that federal lands contain the largest concentration of the country’s mature and old growth forests.
Differences in those definitions are important, because forest policy debates surrounding the responsible management of these forests depend on adequately identifying them, particularly mature forests, which are much more loosely defined than old-growth.
“I think the discussion is almost more about what to do with mature forests, as opposed to old-growth,” says Woodwell Climate senior scientist, Dr. Richard Birdsey, who worked in the U.S. Forest Service for four decades. “Mature forests are at a younger stage of growth—trees would be smaller, although they could still be substantial in size and very profitable to harvest. So the question here is whether to let those forests grow into old-growth characteristics, or to start harvesting them for wood products.”
What do we do with our mature forests?
When climate benefits are explicitly considered, the research points strongly to letting these forests grow—protecting and expanding the massive portion of sequestered carbon they represent.
According to Dr. Birdsey, the largest threat facing mature and old-growth forests in the U.S. is logging, which is a threat that humans can reduce instantly, simply by changing policy. A change that would make those forests more resilient to other threats in the long run.
“Others might argue that climate change or wildfire are more significant threats,” says Dr. Birdsey. “Older forests with larger trees are more resistant to those threats—but not more resistant to chainsaws. That’s a human decision.”
A recent paper in Nature Climate Change has laid out a “protect, manage, restore” framework for making decisions about what natural climate solutions to pursue, and the highest priority is always to protect carbon where it is already stored. U.S. policies have made some recent progress in this direction through the enforcement of the roadless rule on Alaska’s Tongass National Forest, prohibiting road-building and industrial logging on the 9 million acre temperate rainforest. But there is still further to go to capitalize on the carbon storage potential of the U.S.’s mature forests.
Federally managed forests contain more high-carbon trees than other lands, so the opportunity for increased carbon storage within them is greatest. Woodwell Climate Distinguished Visiting Scientist, Dr. William Moomaw, helped coin the term “proforestation” to refer to the strategy of letting forests continue to grow as a carbon solution. In order to achieve that, he says, mature forests have to be protected.
“The next steps should be to provide legal protection of as much of these high-carbon forests as possible,” says Dr. Moomaw. “These are public lands that should serve the public good, and reducing climate change is a public good that we should pursue as the highest priority.”
Transcript edited for grammar and clarity.
Sarah Ruiz: Fire. It’s a transformative force on any landscape, scorching and destroying, but often making space for new life. It also plays a part in transforming our global climate, releasing stored carbon from forests and other ecosystems that we simply cannot afford to add to our atmosphere. I’m here today with three of Woodwell Climate Research Center’s experts on fire and climate change: Dr. Manoela Machado, Dr. Brendan Rogers, and Dr. Zach Zobel. We’re here to discuss how fire fits into the climate change puzzle, as both a symptom and the cause of the warming climate. Consider this a “fireside chat” of sorts. Let’s begin.
Brendan, you work primarily in boreal forests, where fires are a natural part of the landscape, correct?
Dr. Brendan Rogers: Yes, that’s right. So even though boreal forests are in the north and they’re cold and damp for a lot of the year, the surface vegetation in the soil, the soil organic matter can dry out pretty dramatically in the summer. This fuel, as we call it in fire science, often all it takes is just one single ignition source to generate a pretty large wildfire. Humans certainly ignite fires, but still most of the burned area in boreal forests is coming from lightning ignitions.
Fire is also an important natural process in boreal forests. Many of the fires are what we call stand replacing—meaning they’re high intensity, they kill most of the trees, at least in Alaska and Canada. This initiates the process of forest succession, with often different types of vegetation, and tree species playing pretty key ecological roles. But fire regimes are changing and intensifying with climate change, taking us outside the range of what we would consider our natural variability that we’ve seen in these systems for millennia.
SR: Now, Manu, you work in the Amazon rainforest, where fire is never a natural part of the landscape. Can you explain what Kind of role fire plays in a tropical rainforest?
Dr. Manoela Machado: The Amazon biome did not evolve with fire pressure selecting for strategies of survival, which means that the plants are not adapted to this disturbance. Fire is a very powerful tool used to transform the landscape and has been used for millennia. Traditional and Indigenous communities still use it for agricultural purposes, but that’s not the fire that we see on the news, making headlines of “fire crisis in the Amazon.”
Those catastrophic events with lots of smoke in the atmosphere, they’re normally related to deforestation fires, which are fires used after clear cutting to clear out biomass and use the land for cattle ranching and other agricultural purposes. Those fires can escape into forest areas. So the ignition sources are always human—there are no natural ignition sources in the Amazon forest.
SR: With climate change, these dynamics are shifting in many places, as drier and hotter conditions make it easier for fires to spark. Zach, could you talk to us a little bit about what makes a forest susceptible to fire, and how climate change might be affecting that?
Dr. Zach Zobel: Fire weather is a given set of atmospheric parameters that indicate—if there was an ignition source—fire would be able to grow and spread rapidly. What we do is we model what is known as the fire weather index. This index consists of four different atmospheric variables, and those are: temperature (the hotter it is, the more likely vegetation is going to dry out quicker); relative humidity (the lower the humidity, the more rapidly vegetation can dry out); precipitation, both backward looking (“has it rained a lot recently”) and today; and wind speed, because once a fire starts, if the wind is adequately high, that’s when it’s going to spread.
We take those variables out of the climate models, and we model it—what it looks like historically, versus what it’s going to look like in the future. And what we find is that in several fire regimes, most of them actually, these “high fire risk days” are starting to rapidly increase.
We see it especially in the Mediterranean, Brazil, eastern Australia, the Western United States, in several parts of Africa. Over the next 30 years, we think these high fire risk days are going to increase on the order of a couple of weeks in some locations like the Western US, to upwards of one to two months in the Mediterranean and Brazil. And that’s pretty significant, when you think about how historically these days only occurred maybe one week a year.
SR: So what are some of the risk outcomes posed by those more frequent, intense fires, globally?
BR: More frequent intense fires are changing the ecology of many boreal forests in some cases, leading to transition from forest to grassland or shrubland, which of course impacts the resident animals. But there are also large impacts on humans. The smoke from large wildfire seasons is a direct threat to human health, and rural and especially Indigenous communities often feel the largest impacts. Additionally, in areas of permafrost, which is ground that is frozen year after year, fires can lead to permafrost thaw for many years. That can often destabilize the ground leading to ground collapse, presenting a hazard to people that are living in these areas.
MM: I think the Amazon has many similarities with the Arctic, despite being very different environments. Despite not being natural, fires have become a recurrent issue that coincides with the dry season, which then creates what we call the burning season. Any fire is damaging to an environment that is not adapted to it. So there’s the immediate release of huge amounts of carbon when that biomass is burning, and there’s the delayed mortality that understory fires cause, so there’s continued emissions of carbon as well. That can cause a shift in species composition.
And fire also begets fire, which means that forest canopy that is disrupted allows more wind and sun to penetrate the forest, which creates drier microclimates. And tree mortality increases the fuels on the forest floor as well. So a degraded forest becomes even more vulnerable to future burning. As Brendon mentioned as well, there are several studies linking the burning season with higher hospitalization rates of people with respiratory illnesses as well.
SR: So, then what do these changes mean in terms of fire risk? How much of what we’re seeing now is on par with or accelerated compared to what climate models have been showing?
ZZ: Manu, and Brendan just hit it right on the head. What we’re seeing is the driver of these increasing high fire risk days, is largely because the length of the dry season is increasing in many of these fire regimes. Since they talked about the tropics and the Arctic, I’ll use California as an example. The dry season is typically from April to November or December. What makes California almost even more unique is that if this extends later and later into November and December, that’s when the Santa Ana winds start to pick up. So we found that that’s what’s happening in California, the wildfire season is expanding into later in the season. And that’s when their seasonal winds start, ahead of the rainy season.
In terms of risk to life and property, there’s also another factor that I think is a little underappreciated. (and this is happening in the Mediterranean and Australia and some of the major spots I talked about, maybe less so in Brazil, but Chile as well) is people are moving into areas that traditionally have had wildfires, even in the absence of climate change. And so, as we continue to build up property, let’s say in California, in the wildland urban interface as it’s known, that’s when you start to see things unfold, like we saw in 2019, in Australia and the Camp Fire as well in California.
When we talk with our partners, we always show them how rapidly the climate models are viewing this increase in fire weather days. We definitely caveat it by saying, Here’s what the observations are showing us. The climate models aren’t even keeping up with how quickly wildfire risk days are increasing. So we view it as is “this is the best-case scenario for the next 30 years.” And the best-case scenario is scary enough. And that’s kind of the message we send to the people that we work with when presenting this data.
SR: Not only do increased fires have immediate ecological and safety impacts. They also represent a significant risk to our ability to achieve climate goals. Forests are one of our most valuable carbon sinks, and keeping them healthy and standing is essential to curbing warming. Let’s talk a little bit about how fires pose a threat to that.
BR: So boreal forest fires release some of the largest amounts of carbon per unit area for any biome on Earth. And this is because most of the fuel is coming from the soil organic matter or Duff. And most of the climate impacts are from CO2 and methane. But actually, there’s a whole host of gases that are released into the atmosphere. And what’s worse, in areas of permafrost, those fires can induce permafrost thaw and degradation that can also release even more greenhouse gases over the ensuing years. This is what triggers the global feedback mechanisms from boreal fires—climate warming, leading to more fires, which leads to more net emissions of greenhouse gases that further fuels climate warming.
When we combine the carbon release estimates from intensifying fire regimes with the interactions between fire and permafrost thaw, the numbers are somewhat sobering. And they may impact our ability to meet the global temperature targets such as one and a half and two degrees above pre-industrial as set out in the Paris Climate Agreement. These impacts are largely not accounted for in climate models or remaining carbon budgets. So, one big question is what can we actually do about it?
I first want to stress that the fires themselves are not the cause of the problem. They’re a system response to warming. So ultimately, the solution is reducing and eliminating fossil fuel emissions that are warming our climate. That said, we do actually have some level of control over boreal fires through fire management control that we don’t have, for example, when it comes to other bigger system feedbacks. Our group has done some work to show that boreal fire management and specifically suppression of fires when they’re first ignited and relatively small, could be a cost effective way to keep carbon in the ground and protect against rapid permafrost thaw. Actually recently, for the first time, a land management agency in the US has adopted these ideas and designated land in Alaska to be protected from fire purely for the purpose of protecting permafrost and carbon. Of course, there are many, many considerations that come into play with changing land management, for example, the ecological impacts, and of course, the people that live on or near that land, including indigenous communities. So these are really complex decisions. But ultimately, as we’re hopefully headed down a path towards global net zero emissions, towards climate stabilization and eventual climate cooling. I think that limiting boreal fire emissions should be considered as a natural climate solution that also has many co-benefits for the habitat, for human health, and the economy.
SR: So Manu, is fire management also a potential solution for the Amazon?
MM: Um, I don’t think it’s a solution, I think is something that exists, but also kind of in tune with what Brendan was saying that fire is not the core of the issue. In the Amazon, deforestation is the major issue regarding climate change in general. So, this process of land grabbing and clearing for cattle ranching and cropland is the driver of deforestation and for as long as we have that, we will have these catastrophic fire events. These deforestation fires and the leakage that comes from that into forest areas, those are not things that firefighters can face with safety. These are intentional fires, and they’re part of the deforestation process. So, the path to ending these fires is through tackling deforestation. The other types of fires such as pasture fires, forest fires that are not in those areas of like frontier of deforestation, they can be dealt with through prevention and combat actions, such as preparing firebreaks ahead of the expected burning season, and having well trained, well equipped brigades ready for action. And that’s something that we’ve been trying to do as well. We’ve been providing GIS training to Indigenous fire brigades across the Amazon and developed some other partnerships as well with spatial analysis and trying to help out with science too, but the core issue is not fire it’s deforestation.
SR: So, combating fires and learning to manage them when they arise is important, as well as working with communities on the ground to do so. But the root cause of climate change lies in the vast amount of carbon emissions that are released by human activities. Ultimately, bringing fires under control will require mitigating emissions and curbing climate change, otherwise, forest fires might just become too hot to handle. Thank you, everyone, for sharing your perspectives on fire and climate change with us today.
In a world plagued by rapid change and challenges, I think many of us are asking the question: “How can I help?” As individuals, it can be hard to find a way to give back and help steward the natural resources we rely on. But, for those who love fly fishing—anglers—Science on the Fly offers a path to do just that.
Science on the Fly engages the enthusiastic and passionate fly-fishing community, in the US and abroad, as community scientists. Members of the fly-fishing community have close relationships with their local rivers—from having a favorite fishing hole, to knowing the seasonally anticipated flows of the river and when certain bugs are hatching. They also are more aware than most of the impacts of climate change on local fisheries. In states like Colorado or Montana, anglers have given up the opportunity of even casting a fly rod at some points in the summer season. Why? The trout are too stressed and lethargic due to the droughts and rising water temperatures.
Crowdsourcing climate data
Our fly-fishing community scientists are excellent resources for data collection and observation of climate trends to create a clearer picture of how rivers are changing over time. With their help, we can increase the number of rivers subject to long-term studies of water quality and watershed health. Since Science on the Fly was founded in 2019, we have collected data on nutrients and organic compounds from over 350 river sites across the United States each month.
The science collection process is straight-forward and easy. Sample locations are chosen for their accessibility and interest to fly-fishing volunteers, who are responsible for collecting a small bottle of sterile river water from each location once a month, as well as data on air and water temperature. They then freeze the bottles and bulk ship them back to Woodwell Climate Research Center one or two times a year.
At Woodwell Climate’s Environmental Chemistry Lab, we analyze the concentrations of nutrients such as nitrate, phosphate, silica, ammonium, dissolved organic carbon, and total dissolved nitrogen. All data is shared publicly, and after we have a year’s worth of data, we write a report of the state of the river for those sampling locations.
A rapidly expanding network
This project got to where it is extremely quickly. A year after the program was founded, we had grown from two community scientists to 140 enthusiastic river activists. Over the course of four years, more than 7,000 bottles have been placed into the hands of our empowered community scientists.
It is easy to see how we got here so fast; when we offer a tool-kit that is free to the passionate angler and can help them give back to their watershed, they want to get involved. While it isn’t necessarily cheap for us, at a cost equaling $100 a bottle, it is an extremely effective way to add novel data to the climate science dataset on many watersheds—information we wouldn’t be able to gather otherwise.
We’re now exploring how best to integrate Science on the Fly’s water quality sampling and community scientist model with Woodwell Climate’s important research in the Alaskan Yukon-Kuskokwim Delta region. Located at the lowest section of the permafrost belt, this region is experiencing rapid thaw as the climate warms. We ask: Could water quality collection be done in a way that tells the story of the rivers over time? Could anglers floating down these remote rivers provide samples in a timely manner? The answers, we’ve found, are yes, but it has taken some practice to get there, and the region presented unique challenges that we didn’t encounter in other regions.
Our core team at Science on the Fly now rafts, researches, and fishes vulnerable and wild rivers in this region—including the Arolik, Kanektok, Kisaralik, Kwethluk, and the Goodnews—each summer season. Each morning of the trip, the teams gear up and take a variety of samples and water quality measurements—including the collection of our 60 mL sterile river water samples. We also install or retrieve water temperature monitoring sensors in the watershed, so we can see river temperatures from the entire year. Some samples collected during the trips are used directly for the Science on the Fly program, while others help collect data for different research projects associated with Woodwell Climate or other organizations.
Building partnerships to sustain science
These research trips are only answering some of our questions, however. We still want to see these rivers’ nutrient concentrations throughout the summer season—not just when we’re floating (which is normally 10 or fewer days per river). Like most science, it’s not cheap. It’s also not easy to logistically coordinate a river research trip—all the gear, travel, food, science supplies, safety equipment, and qualified team members to float—from afar.
PapaBear Adventures in Bethel, Alaska is our answer to the other half of the questions. PapaBear is an operation that helps the adventurous outdoors person get to the headwaters of remote rivers, and gives them the tools they need to float the rivers on their own. They have been instrumental in meeting the transportation needs of other Woodwell Climate projects like the Polaris Program, and now they are helping Science on the Fly get anglers out to the rivers throughout the summer season.
Beyond working with PapaBear on transportation, Science on the Fly now stations a team member—me or Joe Mangiafico, for now—at PapaBear for the summer months. This team member preps the research team’s trips, making sure they are properly prepared to go down the rivers with all materials needed. But their main goal is to encourage other PapaBear clients and their groups to be involved in the sampling. Pre-made kits are handed out to groups floating these rivers. After the groups get off the rivers, our team member retrieves the filled sample kits and freezes them for shipping back to Woodwell Climate.
The data that has returned from these endeavors is already exciting.
In summer 2021, our Science on the Fly research team sampled 2 rivers, the Kwethluk and Kisaralik, and by a lucky ask to some passing groups of anglers, the Kanektok and Goodnews Rivers were sampled as well. There were a total of 45 samples collected that summer. The following summer, the combination of Science On The Fly research teams and new efforts to increase engagement with volunteer community science groups, allowed us to increase collection to 248 sample bottles. We were able to successfully increase data collection on the other rivers of the Yukon-Kuskokwim delta, and added the Arolik to our list. We hope to accomplish even more in years to come.
Four years of Science on the Fly has shown that community scientists and community science programs can be a powerful way to collect data, conduct research, and educate the public through our reports. Now that we’ve built a solid project structure, with data coming in consistently, we are beginning to switch gears and make an impact with report writing and affecting policy—all while continuing to add to the growing body of water and climate science. We’ll be using community-collected data to create tangible reports for anglers to better understand their watersheds. We will then use these reports to help make an impact on policies, with the goal of creating or maintaining healthy watersheds, especially in the face of climate change. We look forward to continuing to give back to our community scientists and to our rivers.
To learn more about Science on the Fly, visit our website.
A recent paper, led by Woodwell Climate postdoctoral researcher Dr. José Safanelli, revealed that Brazil’s farms have been steadily moving out of the most suitable regions for agriculture—opening up a significant portion of the world’s agricultural production to vulnerability from the changing climate.
The study, published in Applied Geography, used an index to assess “Grain-cropping suitability” for two key staple crops—soy and maize. Suitability was determined by climatic factors (temperature and precipitation), as well as soil quality and terrain. The result was a continuous map detailing the areas of the country with the best biophysical conditions for growing crops.
Overlaying land use change data from the past two decades with this new map revealed a historical trend of agricultural lands expanding towards areas with poorer soil quality and lower suitability for grain-cropping, primarily in the north central and northeastern portion of the country.
Understanding Brazil’s agricultural migration
Farmers in Brazil have been moving north to this “agricultural frontier” since the 1980s— drawn primarily by economic opportunity, as well as the higher quality climate and terrain conditions along the southern edge of the Amazon.
Despite the favorable climate, the soil is inferior. Farmers are seeking cheap land, which often comes in the form of degraded pasture, originally created by clearing forest. Rainforest soils are not naturally nutrient rich and, without any additional inputs, the soil quality becomes depleted after just a few years. Many farmers know this fact, but come anyway. Dr. Safanelli has even seen this trend unfold within his own family.
“I was born in the south of Brazil, a region that has good soil conditions. Recently, two of my uncles who are farmers emigrated to Mato Grosso. There, the climate is wetter and more stable, but the soils are poor—depleted of nutrients.”
Additional research by Woodwell Climate Assistant Scientist Dr. Ludmila Rattis suggests that climatic advantage may be short-lived. Her work indicates that the climate in these areas is changing— becoming drier and hotter as global temperatures rise—and deforestation for agricultural expansion just makes the problem worse.
“We showed in our paper that these places have good climate and terrain suitability for now,” says Dr. Safanelli. “But they are restricted in soil quality. In Mato Grosso—the largest agricultural production state in Brazil—for example, the climate has been more stable and favorable than in other parts. The problem is that, according to projected climate scenarios, climate change may push these areas out of a good suitability space.”
What this means for agriculture in Brazil
Brazil is currently the world’s top producer of soy, and in the top three for maize. But this expansion into lower-suitability regions has introduced greater vulnerability into the agricultural system. Farmers already must provide greater investment in fertilizing the soil to make it productive, which cuts into their margins for profit. Add to that the fact that poor-quality soils, typically low in organic matter, can make crops less resilient to extreme heat and drought.
“Crop evapotranspiration—a process that directly governs crop growth and yield—depends on soil for absorbing rainfall and storing water. These marginal soils can make farmers more susceptible to climate change’s expected drier and warmer conditions, as they have limited capacity for storing water,” says Dr. Safanelli.
Reducing these vulnerabilities, Dr. Safanelli says, will require an integrated approach— improving land management practices and increasing crop yields on existing land to reduce the pressure to expand. “Reducing the vulnerability of croplands may be possible by adopting management practices that increase the resilience of the farming system, such as fully incorporating the principles of conservation agriculture, integrated production through agroforestry, crop-forest-livestock systems, or irrigation to control dryness. And perhaps allocating some of these marginal lands for land restoration, concentrating our resources in more highly suitable croplands.”
Carbon cycling is an essential part of life on the planet. Plants and animals use the element for cellular growth, it can be stored in rocks and minerals or in the ocean, and of course it can move into the atmosphere, where it contributes to a warming planet.
A new study led by Dr. Megan Behnke, a former Florida State University doctoral student and Woodwell Polaris Project participant who is now a researcher at the University of Alaska, found that plants and small organisms in Arctic rivers could be responsible for more than half the particulate organic matter (a carbon-rich nutrient) flowing to the Arctic Ocean. That’s a significantly greater proportion than previously estimated, and it has implications for how much carbon is sequestered in the ocean versus how much moves into the atmosphere.
Scientists have long measured the organic matter in rivers to understand how carbon cycles through watersheds. But this research, published in Proceedings of the National Academy of Sciences, shows that organisms in the Arctic’s major rivers are a crucial contributor to carbon export, accounting for 40 to 60 percent of the particulate organic matter—tiny bits of decaying organisms—flowing into the ocean.
“When people thought about these major Arctic rivers and many other rivers globally, they tended to think of them as sewers of the land, exporting the waste materials from primary production and decomposition on land,” said Dr. Rob Spencer, a professor in the Department of Earth, Ocean and Atmospheric Science at FSU, and collaborator on the paper. “This study highlights that there’s a lot of life in these rivers themselves and that a lot of the organic material that is exported is coming from production in the rivers.”
Scientists study carbon exported via waterways to better understand how the element cycles through the environment. As organic material on land decomposes, it can move into rivers, which in turn drain into the ocean. Some of that carbon supports marine life, and some sinks to the bottom of the ocean, where it is buried in sediments.
The study was supported by the Arctic Great Rivers Observatory, and it examines six major rivers flowing in the Arctic Ocean: The Yukon and Mackenzie in North America, and the Ob’, Yenisey, Lena, and Kolyma in Russia. Using data collected over almost a decade, they built models that used the stable and radioactive isotope signatures of carbon and the carbon-to-nitrogen ratios of the particulate organic matter to determine the contribution of possible sources to each river’s chemistry.
Not all particulate organic matter is created equal, the researchers found. Carbon from soils that gets washed downstream is more likely to be buried in the ocean than the carbon produced within a river. That carbon is more likely to stay floating in the ocean, be eaten by organisms there and eventually breathed out as carbon dioxide.
“It’s like the difference between a french fry and a stem of broccoli,” said Dr. Behnke. “That broccoli is going to stay in storage in your freezer, but the french fry is much more likely to get eaten.”
That means a small increase in a river’s biomass could be equivalent to a larger increase in organic material coming from the land. If the carbon in that organic matter moves to the atmosphere, it would affect the rate of carbon cycling and associated climate change in the Arctic.
“I always get excited as a scientist or a researcher when we find new things, and this study found something new in the way that these big Arctic rivers work and how they export carbon to the ocean,” Dr. Spencer said. “We have to understand the modern carbon cycle if we’re really going to begin to understand and predict how it’s going to change. This is really relevant for the Arctic at the rate that it’s warming and due to the vast carbon stores that it holds.”
The study was an international endeavor— a feature that, Dr. Behnke notes, is critical to Arctic work, especially as climate change advances.
“That pan-Arctic view of science is more important than ever,” Dr. Behnke said. “The changes that are occurring are far bigger than one institution in one country, and we need these longstanding collaborations. That’s critically important to continue.”
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.”