High Lonesome is a working cattle ranch that does things a little differently. The managers of High Lonesome employ regenerative ranching, a technique that works with natural cycles and ecological principles to restore a degraded landscape. The result is a productive ranch with healthy cows, good water retention, a diverse ecology, and—crucially for our work—carbon-rich soils. It’s an ideal location for Woodwell Climate Research Center’s second annual Rangeland Carbon Workshop.
On a beautiful late September day in western Colorado, the Woodwell Climate Rangeland Team (myself, Dr. Jon Sanderman, Dr. Yushu Xia, and Andrew Mullen) gathered at High Lonesome Ranch to lead the workshop in partnership with Colorado State University and Green Groups Graze. We were joined by 45 scientists, ranch managers, members of NGO communities, and representatives from government agencies, all eager to discuss rangeland health, management, and monitoring in the U.S.
Conversations centered on the benefits and challenges of regenerative practices like the ones used at High Lonesome. One core tenet of regenerative ranching is the use of adaptive grazing systems—a concept that promotes the frequent movement of livestock between pastures (whether that’s cattle, bison, goats, or another grazing animal) with short, intense, grazing intervals. Following a grazing event, that land is given a long period of rest and regrowth. These cycles between grazing and rest help promote robust, healthy plant communities with deep root systems. They also keep nutrients cycling through the system, building up a store of water and soil carbon over time.
The growing interest in regenerative ranching across the US (and globally) is being driven by the awareness of increasing impacts from climate change. Severe droughts, flooding, and fire have posed a particular threat to ranching communities. In July 2020 the historic Pine Gulch fire burned through a large portion of High Lonesome Ranch, as well as their grazing leases on adjacent U.S. land. The fire destroyed $1 million in ranching infrastructure and much of the forage needed for grazing that year. It also caused undesirably dense shrubs to replace diverse herbaceous plant species.
On top of climate-driven changes, many ranches in the area are simultaneously dealing with the after-effects of land degradation, lost plant cover, and depletion of soil carbon following decades-to-centuries of misuse. But because ranching communities directly rely on healthy lands for their socioeconomic well-being, many members of these communities are coming forward as good stewards, with the goal of improving private and public lands for the benefit of their families, their country, and future generations.
Throughout the workshop we heard from multiple producers about how they are continuously adapting and evolving their land management practices, building up an arsenal of regenerative strategies by combining their knowledge of ecological principles with what they are observing first hand on the land.
In response to the Pine Gulch Fire, High Lonesome ranch is now adapting by bringing in alternative livestock (goats) to browse down the shrubs, helping to create more structurally and ecologically diverse ecosystems. They are also exploring new methods of sustainable fencing, including a virtual fencing approach where ranchers use GPS-enabled devices that electronically encourage animals to stay within designated grazing areas.
We also discussed how we define the “health” of rangelands in the first place, and how to monitor changes in ecosystem health indicators over time. The importance of monitoring ecosystem health across all U.S. rangelands recently came to the forefront after the bipartisan organization Public Employees for Environmental Responsibility (PEER) released a report in late 2022, based on data from Bureau of Land Management (BLM) monitoring sites on western lands. The report revealed severe declines in the “health, diversity, and productivity” of public grazing lands, primarily driven by overgrazing. The report also emphasized a need to improve data collection and mapping efforts to track range health, while restoring ecosystems through improved management.
But getting to “improved management” and “healthy rangelands”, means filling in information gaps. Our conversations revealed the difference between the kinds of information producers find important in making management decisions, and what information researchers and conservation groups might want to use to understand healthy rangelands.
“Producers need information on the health and vigor of the vegetation in order to make day-to-day management decisions, while conservation groups may be more interested in the broader ecosystem service benefits, such as bird biodiversity and carbon storage, that are emerging from good rangeland stewardship,” says Dr. Sanderman.
Our discussions at High Lonesome indicated a need for a “well-designed, sustainable, wall-to-wall” land health monitoring system for public and private lands alike—something that could integrate producer knowledge with repeated point-based field observations and data provided through remote sensing. A tool like this could help ranchers make decisions that build up carbon storage and provide the ecosystem services that conservation groups are hoping to restore, while also keeping their businesses productive.
As part of her postdoctoral position, Dr. Xia has been constructing a tool to fill this need, aiding ranchers’ decision making around regenerative ranching practices.
“We’ve been working on developing the first version of the Rangeland Carbon Monitoring Tool (RCMT) system, which provides high resolution estimates of rangeland soil carbon and productivity,” says Dr. Xia. “This workshop presented a valuable opportunity for us to gather insights from diverse stakeholders. Their inputs are crucial for us to improve the visualization of our tool.”
Being able to empirically show improvements in carbon storage on rangelands could also help ranchers benefit economically from soil carbon markets—a still-developing strategy for including rangelands in natural climate solutions.
“While there are a lot of debates regarding the practicality of implementing improved rangeland management for economic gains in the carbon market, there is a consensus on the necessity of improved quantification tools like the RCMT,” says Dr. Xia. “These tools are essential to reduce the uncertainty of soil carbon estimates, and thereby facilitate improved rangeland management for multiple ecological benefits.”
Throughout the workshop it also became clear that, in addition to a need for new tools like the RCMT, ranchers need more access to programs that offer community-based networking and knowledge sharing of regenerative practices, as well as support for improving ranch infrastructure to better enact regenerative agriculture. Ultimately, ranchers would also benefit greatly from programs that provide financial payments for ecosystem services provided by healthy open spaces—a model that would allow them to prioritize biodiversity, wildlife habitat, and carbon sequestration in their decision making. Achieving these goals will require changes in programs and policies at all levels, from local to federal, to provide a much-needed investment in the well-being of our rural environments and the health of our planet.
Read the story on Permafrost Pathways.
If the summer of 2023 felt abnormally hot to you, that’s because it was. With heat waves making headlines month after month, this year saw a spike in temperatures that broke global records.
September 2023 followed in the footsteps of both August and July as the hottest each month has been since temperature record-keeping began, making the late summer of 2023 Earth’s hottest yet. Here’s how 2023’s sweltering heat compares to past years:
- Global average surface air temperature reached a record high in the summer of 2023.
- July 24th, 2022 was the hottest day of last year, at 62.5 degrees F.
- July 3rd, 2023 was the first day that was hotter than the hottest day in 2022.
- July 6th, 2023 was Earth’s hottest day on record.
- 42 days this year were hotter than the hottest day in 2022.
Record-breaking heat in 2023
In North America alone, 78 all time records for hottest temperature were broken over the course of June, July and August. In New Iberia, Louisiana, the temperature record was broken four times, peaking at 109 degrees F. Places as far north as Wainwright Airport in Alaska saw temperatures as high as 84 degrees.
Humidity makes the heat deadly
Extreme heat events like these present a serious danger to human health. That threat is multiplied when instances of high temperature coincide with high humidity— interrupting the ability of the human body to cool off through evaporating sweat. A recent paper, co-authored by Woodwell Climate Risk Program director, Dr. Christopher Schwalm, defines “lethal heat” as a wet bulb temperature (a measure combining heat and humidity) of 35 degrees C (95 degrees F). Prolonged exposure— over 6 hours— to temperatures exceeding this can result in death even for a healthy person keeping hydrated in the shade
According to the paper, instances of deadly heat waves are increasing with climate change. Already, with over a degree of warming, parts of Northern India are seeing annual heat events. By just two degrees of warming— a milestone we are currently on track to hit by mid-century— a quarter of the world is expected to experience a lethal heat event at least once in a decade. A significant subset of the world, particularly regions of India, Africa, South America, and the Southeastern US, can expect deadly heat conditions at least once a year at that point, and the area will expand wider with each half degree of warming.
It’s a forecast that highlights the urgency of acting to mitigate warming and developing local and regional strategies to prepare communities to handle high heat and humidity events when they do come.
“It puts this past year’s heat waves into somber perspective,” says Dr. Schwalm. “Without action, we put a lot more, potentially billions, of people at risk of heat stress or death on an annual basis. It’s a significant public health concern.”
On September 27th, Woodwell Climate scientists and policy experts from the Center for Climate and Security (CCS) conducted a briefing on climate security risks in Iran and Türkiye. The presentation, hosted in the Capitol, drew in a crowd of interested congressional staffers to learn more about the relationship between the worsening climate crisis and national security issues.
This was the second of two such collaborative briefings, following a presentation to members of executive branch agencies, including the State Department, Department of Defense, US Institute of Peace, National Intelligence Council, and the Special Presidential Envoy for Climate, earlier in the month. Alex Naegele, a postdoctoral researcher with the Climate Risk Program at Woodwell, presented the results of two risk analyses produced in collaboration with CCS. The analyses used model projections to examine the impacts of climate change on rainfall, water scarcity, and wildfire.
Security experts from CCS— Tom Ellison, Elsa Barron, and Brigitte Hugh— then provided insight into political and social issues in both countries that intersect with climate risks, creating potentially destabilizing effects. In Türkiye, for example, diminishing water resources have the potential to create cross-boundary conflicts if it’s perceived by downstream countries to be “hoarding” water for its own citizens.
The briefing was highly attended by congressional staff across the political spectrum from 27 different House and Senate offices.
“The congressional crowd can be different and you never know exactly what you’re going to get,” says Woodwell External Affairs Manager Andrew Condia. “But you could just tell by the questions, and sort of the attention to the presentation that this was a very relevant and interesting topic across the board. It was a much more bipartisan turnout than I was expecting.”
That turnout speaks to the broad interest in how climate change represents a growing threat to national security interests. By speaking on climate through a security lens, Woodwell scientists are able to broaden interest and attention on climate issues throughout various branches of the federal government.
“Through this collaboration with CCS, we’re able to use our science and forward-looking approach to highlight specific climate risks to the security community. It’s something that’s not widely practiced and it’s a unique position to be in,” says Naegele.
Woodwell and CCS are looking forward to expanding the scope of future climate security case studies to draw links between the impacts of climate change and disruption to other countries or even other social systems.
“It would be interesting to apply this same thinking to an analysis of a certain theme instead of country. Perhaps examining impacts on supply chains or food systems,” says Ellison. “There’s a ton of issues we’ve barely scratched the surface on.”
“There are so many cultural differences to consider,” notes Dave McGlinchey. “From how the meetings proceed, to specific local sensitivities, even down to Congolese humor. Even if I was cracking jokes in fluent French, it would be impossible to get the tone right. That’s why having someone like Joseph was so important.”
In July, McGlinchey, Chief of Government Relations at Woodwell Climate, traveled with members of the Center’s risk team to Kinshasa in the Democratic Republic of Congo for a two-day workshop. The Center has been involved in community work in the country for over 15 years, led in large part by Joseph Zambo, Woodwell’s policy coordinator in the DRC. This workshop represents the latest collaboration— an initial assessment of the country’s future climate risks. Congolese professors, scientists, and government officials joined to discuss gaps in the data and to develop adaptation strategies to be included in a final report later this year.
The workshop was facilitated by Zambo who, with poignant questions, stories to recount, and of course, a bit of humor, guided the group through the tough work of planning for the future.
Expanding access to climate risk data
The community risk work in Kinshasa is one of over 20 successful risk assessments conducted as part of Woodwell Climate’s Just Access initiative. The project produces free, location-specific climate risk analysis for cities and regions both in the US and abroad. The hope is that, by providing free access to quality data— something often offered by private companies at prohibitively high costs — Just Access can facilitate adaptation planning for under-resourced communities.
“With Just Access, we want to remove the barrier of cost for communities that want to understand the long-term risks they are facing because of climate change,” says McGlinchey. “Often these communities are the ones already facing climate-related challenges that will worsen as the century goes on.”
Guided by a community’s particular concerns, Woodwell’s Risk team works with available data on key climate risks—flooding, heat, water scarcity, fire— and uses models to construct an image of how those events are likely to change as global temperatures climb. In the DRC, water is a core concern, both in its absence, causing drought and crop failure, and in its abundance.
“Heavy rains cause horrific flooding in the city of Mbandaka almost once or twice a year,” says Zambo. “In the capital, heavy rains are also destroying homes, roads, electrical structures, and internet connections.”
The most pressing risks vary from region to region. Across the world, in Acre, Brazil, Senior Scientist Emeritus Dr. Foster Brown says, “the word here is ‘heat.’” In Homer and Seldovia, Alaska, increasing wildfire days featured heavily.
But improvements in data availability and resolution, as well as refinements of climate models, have made it possible to replicate assessments for a variety of risks in places as distant and different from each other as Homer, Alaska and Kerala, India. Risk assessments can offer both region-wide crop yield estimates and street-level maps of flooding for a single city district to inform community planning.
It’s about building trust
Key to the success of municipal-level work are relationships with people like Zambo, who can offer insights into the needs of a community that can’t be approximated from the outside. Each community is different— in what information they need to make decisions, their level of technical expertise, their governmental capacity to implement changes, and in the ways they prefer to work.
So, with each new assessment, the Risk team starts from scratch, building new relationships and listening to community needs. This process takes double time on the international stage, where a history of superficial NGO and academic involvement can overshadow collaboration.
“A main goal with these reports is trust,” says Darcy Glenn, a Woodwell Climate research assistant who organized a risk assessment and workshop for Province 1 in Nepal last year with help from connections from her master’s program. “Building trust in the models, and trust in the methodology, and in us. That’s been our biggest hurdle when working with municipal leaders.”
Building that trust takes time. Province 1 was one of an early set of communities who worked with Woodwell Climate on risk assessments. While local leaders were interested in flooding and landslide risk information, what they really wanted was to increase the capacity of their own scientists and government employees to conduct climate modeling themselves. So the project was adapted to meet that need by tailoring a training workshop. The process took over a year to complete but Glenn says, that’s relationship-building time that can’t be rushed.
It also highlights the importance of pre-established long term connections in the places we work.
“It’s one thing to go into a new community by yourself, it’s another to go in with someone who has been there 30 years and can help navigate,” says Dr. Brown. “You have to look for the key people who can help make things happen.”
Within Brazil, Dr. Brown is now regarded as one of these “key people”. He has been living and working in Rio Branco for over 30 years and his credibility as a member of the community helped facilitate an assessment of extreme heat risk in the region. In the DRC, Zambo has been working with Woodwell Climate on various projects for over a decade. Without their expertise to bridge cultural and language gaps, completing projects in Brazil and the DRC would not have been possible.
Working for the Future
After getting risk information into the hands of communities, then comes the hard work of putting it to use. For Dr. Christopher Schwalm, Director of Woodwell Climate’s Risk Program, “the goal of the risk assessments is to give communities every potential tool we can to build resilience for themselves and future generations. With access to the right information, the next step in the adaptation planning process can begin.”
In Rio Branco, Dr. Brown says speaking to the changes people are already noticing has helped individuals connect better to the data. He’s been using the context of heat and fire alongside information from their report to strengthen conversations about existing forest and climate initiatives, authoring an alert for the tri-national “MAP” region (Madre de Dios in Peru, Acre in Brazil, and Pando in Bolivia) about heat conditions and the implications for this year’s fire season.
He has also been introducing the information from the report to the community in other ways— teaching and speaking at events. According to Dr. Brown, widespread understanding of both near- and long-term climate risks will become more important for all communities as climate change progresses and impacts each place differently. Cities and towns will need reliable information to help them practically plan for the future.
“We’re trying to get people to expand their time ranges and start thinking about the future. And this report has helped,” says Dr. Brown. “Because the people who are going to see 2100 are already here. What will we be able to tell them about their future?”
It didn’t matter that she didn’t speak any English at the time, or that the American researchers who had chartered her father’s boat that summer didn’t speak any Russian, 14 year-old Anya Suslova was a quick learner. She watched them dip sample bottles into the Lena River, filter the water, and mark information down on the side of the bottle. By the end of the two week research expedition, Suslova had mastered the protocol and was helping Dr. Max Holmes and his fellow scientists collect water samples.
When the scientists returned to the United States, they left behind some equipment, in case Suslova and her father were interested in sampling throughout the winter. After a year without contact with Suslova, the researchers were delighted to return to the Lena the following summer to find months of samples and a neatly organized logbook she made.
Twenty years later, Suslova is a Research Assistant at Woodwell Climate Research Center who continues to bring her expertise and unique perspective to the Arctic Great Rivers Observatory (ArcticGRO). Since 2003, participants of ArcticGRO—scientists and Arctic community members alike—have been sampling water from the six largest rivers in the Arctic: the Ob’, Yenisey, Lena, and Kolyma in Siberia, and the Yukon and Mackenzie in North America. It’s a rare example of a long-term research project, designed to span decades, deepening our understanding of change across the years.
We need to establish baselines
The Arctic is warming, on average, at least two times faster than the rest of the planet. We need to know the implications of this, but it can be difficult to study ecosystem change across such a vast area. Rivers can offer insights. The chemistry of a river connects environmental processes across its watershed, and the dissolved and particulate materials that are carried to the ocean can influence marine chemistry and biology. Measuring the concentrations of these materials, and how they are transported by rivers, provides vital information about changes in the linkages between terrestrial and aquatic ecosystems.
“Global climate change is rapidly and disproportionately affecting northern high latitude environments,” says Dr. Scott Zolkos, a Research Scientist at Woodwell Climate and one of ArcticGRO’s lead scientists. “Monitoring Arctic river chemistry is critical for detecting trends and understanding the effects of environmental change on northern ecosystems.”
In order to uncover those trends and effects, need to establish baselines on the key chemical constituents within rivers — organic matter, inorganic nutrients like nitrogen, sediments— to compare against future measurements. The more data gathered, the easier it is to sift out annual variability from longer term trends.
So, using Arctic rivers as sentinels of ecosystem health and environmental change was the idea behind the project’s creation, but it was the international collaboration that started with Suslova that gave ArcticGRO its longevity. The project leaders realized that enlisting the help of trained local residents could allow for sample collection in places, and during times of the year, that the researchers themselves couldn’t access. It also helped build enthusiasm for the project among Arctic communities.
“I believe that ArcticGRO has been able to go for so long because it is built on trust and a shared goal between scientists and local people who collect water samples,” says Suslova. “Amazingly the team of ArcticGRO hasn’t changed much over the last two decades, many of the original members are still involved. It feels like a family.”
Now, 20 years after its inception, the ArcticGRO team has published a paper in Nature Geoscience on long-term trends in pan-Arctic river chemistry. The team found strong signals of environmental change for some chemical constituents, but not in others. Alkalinity, which reflects rock weathering, increased in all rivers, while nitrate, an important nutrient for terrestrial and aquatic organisms, decreased. The authors hope the data and insights from this work will be invaluable to scientists refining models of the Arctic system.
“There’s nothing quite like ArcticGRO,” says Dr. Zolkos. “It’s unique in that it measures a comprehensive suite of chemical parameters across the Arctic’s largest rivers, uses consistent sampling and analytical methods across the rivers, and sampling occurs at the same times and locations. The consistency of ArcticGRO is increasingly valuable, because it is building a dataset which allows scientists around the world to detect, monitor, and understand northern environmental change in ways that no other scientific program does.”
We never would have known
A few thousand miles south of the Arctic circle, on the marshy coastline of Massachusetts, another long-term ecological research project has entered its third decade as well. The brainchild of Senior Scientist Dr. Linda Deegan, the TIDE project is unique even among long-term studies. Rather than simply monitoring the nutrient flows in the salt marshes of Plum Island Estuary, the TIDE project has been altering nutrients in carefully controlled amounts to understand the long term impacts of human development in coastal ecosystems.
TIDE focuses on nitrogen, an element of most fertilizers and a common pollutant from developed areas in the uplands. Previous studies of nitrogen impacts indicated coastal marsh plants could absorb a lot of nitrogen with no ill effects. But that dynamic was only examined on short time scales, and in small plots of marsh. Whether there were changes that might require many years or many acres to be detected, was unknown.
Thus TIDE was designed to increase nitrogen concentrations in the water to mimic coastal eutrophication across three marshes in the Plum Island estuary and document which effects might cascade through the system. The initial grant was for five years, but Dr. Deegan and her collaborators wanted to keep the project running for at least a decade, if not more, expecting the changes might be slow to reveal themselves.
After years of observations, Dr. Deegan says she remembers the exact moment they discovered a significant change.
“Several of the senior scientists—myself included—came back at the end of a long field day each of them saying, ‘I don’t remember it being this hard to walk through the nutrient enriched marsh when we started this project. Am I just getting older or has something changed?’ And then one of the new students said, ‘I thought that marsh was always like that—well, it’s not like that in the other sites where we haven’t added nitrogen.’”
So they followed the hunch, made some new measurements, and found the structure of the marsh had changed significantly with the added nitrogen. The plants, suddenly awash in a necessary component for growth, no longer needed to dedicate their energy to making roots to seek out nutrients; their root systems were shallower and less dense, thus less capable of holding the marsh together. At the same time, nitrogen-consuming microbes were breaking down organic matter in search of carbon to fuel the chemical processes that allow them to take up nitrogen. This combination made the marsh creek edges more susceptible to erosion by tides and storms.
It took more years than most experiments are run for, but increased susceptibility to erosion steadily altered the shape of stream channels. The ground along the edges of the streams, previously held in place by a deep network of roots, now collapsed underfoot. Chunks of marsh fell off the edges as the roots no longer held the marsh together. As the years went on, fish and other organisms that travel along stream floors to seek out food began to suffer from difficult terrain, resulting in slower growth and fewer fish.
These findings, published in Nature, upended the way people thought about the effects of eutrophication on marshes. “And we never would have known any of that,” says Dr. Deegan. “If we hadn’t done the project at an ecosystem scale and over such a long time.”
A pipe you can turn off
Over the decades, the TIDE project not only faced the challenges of running a consistent project for so long, but also of justifying making intentional changes to an otherwise healthy ecosystem. The question lingered: If the goal is to protect ecosystems from human disruption, what do we gain from knowingly tinkering with them?
Humans have already accidentally conducted thousands of ecological change experiments across the globe. Casually inflicted pollution, deforestation, or extinction with no control group, no careful observations, no time limits or safeguards—by scientific standards these are reckless and poorly designed experiments.
In Dr. Deegan’s mind, this makes controlled studies like TIDE even more significant.
“We need to know the true impact of the changes that we are already imposing on the environment. And once we do, we need to be able to halt those changes that threaten the integrity of an ecosystem.” Says Dr. Deegan. “This is a pipe I can easily turn off. Not like when you build a housing development and then you’re stuck with all those houses and their impacts forever.”
Climate change is perhaps the most all-encompassing of these involuntary experiments. As ArcticGRO’s and TIDEs results indicate, ecosystem responses to human disturbance, whether it is climate warming or nutrient over enrichment, are complex. Understanding and adapting to these responses will depend on continued monitoring, observation and experimentation.
A testament to the people
In the world of research, rife with limited grants and time-bound fellowships, ArcticGRO and TIDE have been uniquely successful. Research Associate, Hillary Sullivan, who has been part of the TIDE project since 2012, attributes this to the dedication of the researchers, who showed up year after year to get the research done even when funding wasn’t certain or while enduring a global pandemic.
“These large scale projects are a testament to the people that are involved in the effort, and the work that goes in behind the scenes to keep it running,” says Sullivan.
Both ArcticGRO and TIDE plan to continue. ArcticGRO is seeking additional funding to analyze new chemical constituents and continue providing invaluable data for scientists and educators to understand how rivers are responding to a warming climate. “ArcticGRO has improved our understanding of the Arctic, and our work is just getting started,” says Dr. Zolkos. “Continuing will be essential for generating new insights on climate change, northern ecosystems, and societal implications.”
TIDE has now shifted to a new phase of study — observing the legacy of the added nitrogen on marsh recovery in the face of climate change induced sea level rise. Nitrogen additions were halted 6 years ago and researchers hope to gain insights into marsh restoration and ways to improve their resilience to sea level rise.
Thinking in the long-term is not something humans have historically excelled at, Dr. Deegan admits. But the more we try to expand our curiosity past immediate cause and effect, the better we get at understanding nature. If you want to understand an ecosystem, you have to think like an ecosystem—which means longer time scales and larger areas that encompass every aspect of the system.
“Nature tends to take the long view and people tend to take the short,” says Dr. Deegan. “So if you can stick with it for the long view, I think you see things in a very different way.”
Arctic wetlands are known emitters of the strong greenhouse gas methane. Well-drained soils, on the other hand, remove methane from the atmosphere. In the Arctic and boreal biomes, well-drained upland soils cover more than 80% of the land area, but their potential importance for drawing methane from the atmosphere—the underlying mechanisms, environmental controls and even the magnitude of methane uptake—have not been well understood.
A recent study led by researchers from the University of Eastern Finland and University of Montreal, in collaboration with Woodwell Climate Research Scientist, Dr. Anna Virkkala, has expanded our understanding of these dynamics, finding that Arctic soil methane uptake may be larger than previously thought. The results show uptake increasing under dry conditions and with availability of a type of soil organic carbon that can be used in microbial uptake processes.
The study was primarily conducted at Trail Valley Creek, a tundra site in the Western Canadian Arctic. The authors used a unique experimental set-up consisting of 18 automated chambers for continuous measurements of methane fluxes. No other automated chamber system exists this far North in the Canadian Arctic, and only few exist above the Arctic circle globally, most of which are installed at methane-emitting sites.
The high-resolution measurements of methane uptake (more than 40,000 flux measurements) revealed previously unknown daily and seasonal dynamics: while methane uptake in early and peak summer was largest during the afternoons, coinciding with maximum soil temperature, uptake during late summer peaked during the night. The study shows that the strongest methane uptake coincided with peaks of ecosystem carbon dioxide respiration—meaning that as methane is removed from the atmosphere, carbon dioxide production in the soil is high. Complementing flux measurements at Trail Valley Creek with measurements at other sites spread across the Canadian and Finnish Arctic showed that the availability of soil organic carbon and other nutrients may promote methane consumption in Arctic soils.
“The methane cycle has previously been primarily studied in wetlands because of their high methane emissions, but this study shows that drier ecosystems are also very important in the methane cycle,” says Dr. Virkkala.
These findings are highly relevant for estimating the current Arctic carbon budget, and for predicting the future response of Arctic soil methane uptake to a changing climate. According to the study, high-latitude warming itself, occurring up to four times faster in the Arctic than the rest of the world, will promote atmospheric methane uptake to a lesser extent than the associated large-scale drying.
“The Arctic methane budget has remained highly uncertain,” remarks the paper’s lead author, Dr. Carolina Voigt. “Our research provides one potential mechanism that might explain those uncertainties, and highlights the importance of methane measurements in drier ecosystems to calculate more accurate methane budgets.”
Climate change is having profound effects on the chemical composition of large Arctic rivers, signaling changes both on land and in the coastal ocean, according to new international research examining chemical signatures in rivers across Canada, Alaska and Russia.
The study, the result of a two-decade effort by the Arctic Great Rivers Observatory, analyzed nearly twenty years of water chemistry and discharge data collected from six rivers that comprise 60 percent of the Arctic Ocean watershed.
The researchers tracked river water ions, key nutrients, and dissolved organic carbon, among other indicators. They found that chemical concentrations changed substantially over the past two decades, but trends across chemical groups were different, with some increasing, some decreasing, and others showing little change.
The international scientific collaboration tracked river water ions, key nutrients and dissolved organic carbon among other metrics. Chemical concentrations changed substantially over the past two decades, but trends across chemical groups were different with some increasing, some decreasing, and some showing little change.
“The only way that this divergence in trends is possible is if multiple factors of change are being brought to bear on the Arctic system at the same time,” says Woodwell Research Assistant, Anya Suslova and co-author on the paper. “We know that permafrost is thawing, vegetation is changing and moving northward, and processing of nutrients and organic matter may be happening more quickly. Global climate change appears to be causing many systems that are critical for ecosystem function to change at the same time—and that change is showing up in the chemical composition of river water.”
Key nutrients observed in river water are declining, according to the study. This trend suggests warming temperatures are increasing biological uptake of nutrients on land or in aquatic ecosystems, leading to an overall decrease despite factors like wildfire and permafrost thaw releasing more nutrients into the waterways.
ArcticGRO represents a partnership between researchers at Woodwell Climate Research Center, University of Alberta, the Marine Biological Laboratory, Florida State University, and the University of New Hampshire, as well as scientific and community collaborators in Siberia and the North American Arctic.
“The success of this study is largely due to its collaborative nature,” says Dr. Max Holmes, Woodwell Climate President and CEO, and founder of the ArcticGRO project. “Without the dedication of scientists and community members across the Arctic, we never would have been able to generate the comprehensive dataset that allowed us to uncover these insights.”
Because trends in river water chemistry are not always acting in the same direction, Dr. Holmes and Suslova say the study will help give scientists a blueprint for thinking about how Arctic change will play out.