Methane Production in the Arctic: Under-recognized Cold Season and Upland Tundra - Arctic Methane Sources-UAMS

Lead Research Organisation: University of Sheffield
Department Name: Animal and Plant Sciences


In this project, we will use state of the art approaches and knowledge to better understand the current patterns of and controls on methane (CH4) release from the Arctic to the atmosphere and to improve major models to better simulate future releases of CH4 from the Arctic as the planet warms. Atmospheric methane (CH4) is the second most important greenhouse gas (after CO2) that has strong anthropogenic origins. High northern latitude terrestrial ecosystems account for ca. 50% of extra-tropical biogenic wetland emissions. More importantly methane emissions from the Arctic could increase dramatically in the future. The very large organic carbon stocks (>1,300 GtC) in the top 3 m of Arctic soils and the rapid climate change experienced and predicted in the Arctic, results in a very real possibility of large biogenic CH4 release from these soils in this century. Despite the importance of CH4 fluxes from the Arctic, now and in the future, biogenic and total natural CH4 emissions are poorly understood and very poorly modelled (Fisher et al., 2014).
In 2013, we updated five eddy covariance (EC) towers in Arctic Alaska to operate reliably year-round and measure CH4 fluxes. Initial measurements yielded two unexpected and highly significant findings: 1) cold season CH4 emissions account for >50% of annual emissions and 2) drier upland tundra are larger emitters of CH4 than wetter inundated tundra (Zona et al 2016 PNAS). These observations and processes are not now incorporated in leading global land-surface/carbon-cycle models used to calculate current and predict future CH4 emissions from the Arctic. Verifying this new understanding and incorporating this understanding into models used in the UK and elsewhere will revolutionize our ability to accurately calculate and model terrestrial CH4 fluxes. These results, if supported by the outputs of this project, are critical to verifying current baseline emissions, detecting a changing baseline, and for predicting, with confidence, biogenic CH4 emissions from the Arctic in the future. This project has two overarching objectives: (1) determining the patterns of, controls on, and importance of cold season and upland tundra in Arctic CH4 emissions; (2) incorporating this understanding into JULES, LPJ and TCF, thus significantly improving our ability to estimate current and predict future CH4 fluxes in the Arctic. This work is expected to impact policy through new information and model development, reported through conferences and publications and referenced in upcoming IPCC reports. In the project, we will continue year-round observation of methane release to the atmosphere, and the atmospheric and soil environment that corresponds to these fluxes. We will initiate new experiments and observations to understand the processes and conditions controlling the observed CH4 fluxes including a new system of measurement of CO2, CH4, and 222Rn concentrations that allow autonomous, year-round, determination of CH4 production, consumption, and flux by soil depth and snow layer. We will measure year-round [CH4] and d13CH4 will help identify the importance of methane oxidation in surface soil layers at different locations and seasons. And we will determine the role of GPP in controlling rates of CH4 production. We will also determine the importance of vascular plants in providing a conduit for CH4 produced at depth, to escape to the atmosphere past an oxidizing surface layer.
This new information will inform model development and improvement of models used by the Arctic community. Performance of these models will verified with unique data sets not used in model development. As a result, we intend UAMS to have a major impact on the communities' ability to calculate current and to predict with confidence future Arctic CH4 emissions in a changing world and thereby better inform policy decisions.

Planned Impact

Knowledge of the impact of climate change and rising atmospheric [CO2] on greenhouse gas (GHG) emissions (especially of CO2 and CH4) is critical for setting targets for GHG emission reductions and to identify and promote mitigation strategies. The overarching aim of this project is to fill a major gap in knowledge and answer the question:

"What is the effect of climate change on CH4 fluxes from tundra ecosystems"? The information acquired by the field observations, will be used to test and refine models describing the response of the tundra C balance and GHG fluxes to climate warming. This will allow the models used to be improved, better constrained, and will thereby improve confidence in predictions of future responses. The new understanding will be build into the UK community model (JULES) and code made available to other land surface models. Overall, this project is critical to refining predictions of future feedbacks from the Arctic with anticipated global warming, and better inform policy on the sensitivity of the substantial C pool of arctic permafrost soils to climate change.


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Title Native children view of climate change in Alaska 
Description We worked with fifth grade children in Utqiagvik (Barrow) both to educate them, but also to engage them in helping us communicate to rest of the world, in an emotionally resonant way, the direct impacts of climate change on families in this Arctic region. The team consisted of a scientist from our team (Lipson), an artist (Reasor) and an outreach specialist (Erickson) of Inupiat heritage from a village in Alaska. We worked with four 5th grade classes of about 25 students each at Fred Ipalook Elementary in Utqiagvik, AK. The scientist gave a short lecture about sea ice and climate change in the Arctic, with emphasis on local impacts to hunting and infrastructure (with interjections from the local outreach specialist). We then showed the students a large poster of historical and projected sea ice decline, and asked the students to help us fill in the white space beneath the lines. The artist led the children in making small art pieces that represent things that are important to their lives in Utqiagvik (they were encouraged to paint animals, but they were free to do whatever they wanted). We returned to the class later that week and had each student briefly introduce themselves and their painting, and place it to the large graph of sea ice decline, which included the dire predictions of the RCP8.5 scenario. At the end we added the more hopeful RCP2.6 scenario to end on a positive note. The artist then painted in the more hopeful green line by hand. The result was a poster showing historical and projected Arctic sea ice cover, with 100 beautiful paintings by children of things that are dear to them about their home being squeezed into a smaller region as the sea ice cover diminishes. We scanned all the artwork to make a digital version of the poster, and left the original with the school. These materials are being converted into an interactive webpage where viewers can click on the individual painting for detail, and get selected recordings of the children's statements about their artwork. This project can serve as a nucleus for communicating to other classes and adults about the real impacts of climate change in people's lives. 
Type Of Art Artwork 
Year Produced 2019 
Impact The predominantly Inupiat people of Utqiagvik, Alaska are among those who will be most impacted by climate change and the loss of Arctic sea ice in the near future. Subsistence hunting of marine mammals associated with sea ice is central to the Inupiat way of life. Furthermore, their coastal homes and infrastructure are increasingly subject to damage from increased wave action on ice-free Beaufort and Chukchi Seas. While the people of this region are among the most directly vulnerable to climate change, the subject is not often discussed in the elementary school curriculum. Meanwhile, in many other parts of the world, the impacts of climate change are viewed as abstract and remote. The goal of this creative activity educated and engage children in Utqiagvik to understand the direct impacts of climate change on families in this Arctic region. 
Description Over the last years we continued the measurements of the CH4 loss during the cold period. We show that the later soil freezing (1.67 days y-1 later over the last 16 years) across a variety of sites in the North Slope of Alaska, and the longer "zero-curtain" (i.e. period when soil temperature hovers around zero) is cross-correlated to an increased CH4 concentration during the fall period. Methane emissions across 11 site-years from five sites in the North Slope of Alaska remained consistently higher during the zero curtain than after complete soil freezing. Higher CH4 loss due to prolonged emissions suggest that later soil freezing could explain some of the observed enhancement of in the fall atmospheric CH4 concentration in the Arctic.
Exploitation Route improve prediction of the impact of climate change on C loss form the Arctic, to refine estimates of the cost of climate change to society
Sectors Education,Environment

Description Summary for policymakers interested in the impact of climate change on society.
Sector Environment,Government, Democracy and Justice
Impact Types Societal,Economic,Policy & public services

Description Washington post article
Geographic Reach Multiple continents/international 
Policy Influence Type Citation in other policy documents
Description H2020-INTegrated ARctic Observation System (INTAROS)
Amount € 15,000,000 (EUR)
Funding ID 727890 
Organisation European Union 
Sector Public
Country European Union (EU)
Start 01/2017 
End 01/2022
Title High temporal resolution temperature profiles 
Description High resolution temperature profiles across multiple vegetation types: thermocouples are located every 5 cm, and recorded every second, which will enable continuous measurement of water table and thaw depth across the season, and understanding the soil freezing in the fall, and thawing in the spring. 
Type Of Material Improvements to research infrastructure 
Year Produced 2018 
Provided To Others? No  
Impact this system will provide the ability to resolve the soil freezing and thawing dynamic at an unprecedented temporal resolution, which will support development of methane models 
Title Identifying the environmental and vegetation controls of heat penetration into the arctic soils 
Description To define the vegetation and environmental controls on the heat penetration into the soil, and the thawing the permafrost, temperature readings were collected from 5 cm above the surface (to collect air temperature) and from surface until 20 centimeters below-ground (every cm) on a weekly basis using a portable CR3000. These temperature profiles allowed to determine how the presence and thickness of the moss layer affected the heat penetration into the moss and soil layers. These 21 thermocouples were attached to a fiberglass probe which facilitated insertion in the moss layer and in the soil. Each point was measured for approximately 3 minutes given that this was the time it took for the temperature readings to stabilize. Given that heat penetration is affected by moisture, we also collected volumetric water content (%) weekly using a FieldScout TDR300 and a 5-cm probe. The FieldScout was calibrated using local water samples to account for nutrients which may influence conductivity. Thaw depth and water table levels (cm) were also collected weekly using a metal and wooden probe respectively with markings indicating intervals of 1-cm depths. Water table measurements were taken collected inside PVC pipes (with holes every 1 cm) previously installed along the transects (Zona et al., 2012) where the other measurements were collected. All described data collection was performed in 2-meter intervals for a total of 62 points at each 124-meter transects in both US-Ben, and US-Bec. 
Type Of Material Improvements to research infrastructure 
Year Produced 2022 
Provided To Others? No  
Impact The tool developed is not published yet. Once it will be published in a peer reviewed publication, it will support the development of models trying to identify the controls on permafrost degradation. 
Title Development of CLM microbe 
Description The CH4 fluxes, soil DOC, CH4 and CO2 concentrations among different landscape types were simulated by the CLM-Microbe model with considerations of the specific soil hydrological conditions. 
Type Of Material Computer model/algorithm 
Year Produced 2020 
Provided To Others? Yes  
Impact improve model simulation of the sensitivity of carbon stored in the Arctic to climate change can affect policy 
Description I?isagvik College Barrow 
Organisation State of Alaska
Country United States 
Sector Public 
PI Contribution trained students on research in Alaska
Collaborator Contribution students helped collect field data
Impact data collected after our team left the field
Start Year 2016
Description EGU Session 2021: Effective communication of scientific & place-based knowledge of Arctic change: understanding interactions between indigenous & local knowledge, and natural & social science perspectives 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Below is listed the description of the EGU session: World-wide an increasing number of research projects focus on the challenges associated with changes in the Arctic regions. Whereas these often have a natural and physical science focus, this session focuses on trans-disciplinary approaches to study the multiple phenomena associated with global warming, especially but not exclusively in Arctic regions. Another focus is to understand better how to tackle these in large, trans-disciplinary research projects, initiatives and programs (e.g. HORIZON2020 Nunataryuk, INTAROS and the T-MOSAIC program of the International Arctic Research Council, NSF Navigating the New Arctic, NERC, UAMS), as well as communicating results effectively to the public in terms of outreach and education. Contributions are invited, but are not limited, to the following themes:
• science communication, education and outreach tools, and co-production of knowledge
• integration of social and natural science approaches
• indigenous and collaborative approaches to adaptation and mitigation, equitable mitigation, and risk perception
• socio-economic modelling in relation to Arctic environmental change,
• examining the impacts of permafrost thaw and other phenomena on health and pollution as well as infrastructure (and consequences of the built environment).

One of the aims of this session is to bring together researchers from both social and natural sciences who are involved or interested in reaching out to stakeholders and the general public, and share successful experiences. Examples from past, ongoing and future initiatives that include traditional indigenous knowledge and scientific tools and techniques are welcome.

We are also excited to let you know that our ERL special issue called 'Focus on Arctic Change: Transdisciplinary Research and Communication' is now open for submission. See the webpage: Please consider submitting your manuscript until or preferably before the 31st of May 2021.
Year(s) Of Engagement Activity 2021
Description EOS article 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact article on EOS describing our research results:
Methane-Releasing Tundra Soils Freezing Later Each Year
Year(s) Of Engagement Activity 2019
Description Press release of journal article 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Embargoed until 21 March 10AM GMT

Earlier snowmelt causing knock-on effects for Arctic carbon

? Arctic warming is causing earlier snowmelt and longer growing seasons in Arctic tundra ecosystems
? It was previously assumed that this would cause an increase in carbon sequestration in these regions
? New research has found that earlier snowmelt actually causes a loss in net carbon sequestration later in the year

Earlier snowmelt and Arctic greening are affecting carbon sequestration later in the year in northern Arctic regions.

New research has found that earlier snowmelt and a longer growing season, caused by climate change, are not causing a consistent increase in carbon sequestration as first thought.

It has long been assumed that this longer period of growth and plant productivity would lead to an increase in the summer carbon sequestration, the process of capturing and storing atmospheric carbon.

The findings published in Scientific Reports, however, show that whilst there is an increase in carbon sequestration during June and July, it leads to a loss in net carbon sequestration later in the season around August time.

Dr Donatella Zona, from the University of Sheffield's School of Biosciences and the Department of Biology at San Diego State University and lead author of the research, said: "Climate change is having a major impact on the Arctic and Arctic warming, earlier snowmelts and Arctic greening are causing changes to the atmospheric carbon there.

"Our results show that the expected increased CO2 sequestration arising from Arctic warming and the associated increase in growing length may not materialise if tundra ecosystems are not able to continue capturing CO2 later in the season.

"The results should be considered when predicting the overall response of the Arctic carbon balance to climate change."

The study was carried out using an extensive dataset from 11 sites in Arctic tundra ecosystems across Alaska, Canada, Greenland and Russia, allowing researchers to test the response of a wide range of sites to the earlier snowmelt.
Year(s) Of Engagement Activity 2022
Description Prospective on Climate Change Impact in the Arctic for NASA 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Prospective on Climate Change Impact in the Arctic for NASA. Given my increased standing in my research field, and the substantial impact of the paper I published in PNAS in 2016, I was contacted by a journalist from "Sensing Our Planet" (a publication supported by NASA) that asked me to write a prospective on the importance of cold periods for Arctic ecosystems, and about the importance of my research results. In this feature, I explained why these freezing periods are important and how climate change is likely to affect emissions of greenhouse gases from tundra ecosystems.
Year(s) Of Engagement Activity 2017
Description interview 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact I discussed the importance of methane release during the cold season, and what are the wider implications to society, and why people should care.
Year(s) Of Engagement Activity 2018