Is the Arctic Methane budget changing?

Lead Research Organisation: Royal Holloway, University of London
Department Name: Earth Sciences

Abstract

Methane (CH4) is the second (after CO2) most important greenhouse gas. Sources of CH4 to the atmosphere, both natural and human-driven, have been intensively studied and are now well established; however, their global and regional estimates still suffer from large uncertainties. The region above the Arctic Circle is very important from this perspective because of a unique combination of CH4 emission sources which are active now, e.g. wetlands and forest fires, and those which may become active in the future owing to regional climate change. Potentially important future sources include thawing permafrost soils and CH4-rich oceanic sediments (clathrates). Since the Arctic has been warming much faster compared to the rest of the world, this may trigger various changes in the active CH4 sources as well as those that represent large pools of carbon (permafrost soil) or gaseous CH4 (clathrates). The goal of the proposed project is thus to locate and quantify major sources of Arctic CH4 emissions to the atmosphere and contribute to understanding how these emissions may change with further regional climate warming. At present, the number of Arctic CH4 measurements is simply not sufficient to either make reliable estimates of regional CH4 sources or to understand recent trends in atmospheric CH4 concentrations. In addition to scarce measurements, most Arctic CH4 studies have been supported by campaign-based observations of the local processes responsible for CH4 emissions, mostly in summer when the region is most accessible. But owing to the episodic, and in some instances seasonal, nature of most CH4 source emissions paired against sporadic campaign-based sampling, it has not been possible to produce reliable emission estimates of different Arctic CH4 sources. To address this problem, we propose to establish year-round continuous measurements of CH4 concentration and isotopic composition in ambient air, and to synchronise campaign-based studies with the expected seasonality and location of the CH4 source emissions. Since CH4 emitted from different sources has distinct isotopic 'signatures', it is possible to attribute the observed emissions to the particular sources. This approach requires a retrospective analysis of the air mass trajectories to establish the origin of air with the observed isotopic signature. To be more specific, we propose to establish continuous CH4 measurements at Teriberka, Russia (69.2N, 35.1E; NW Russian Arctic coast), which will provide new insight into central Eurasian Arctic processes. In addition, we plan to carry out detailed isotopic studies of ambient air from several locations in the European and Russian Arctic. These will be compared with records of Arctic air reaching the UK at measurement stations at Barra (Scotland) and Weybourne (Norfolk). Combining our datasets with those from the small number of other Arctic stations of our international colleagues, we will determine whether ongoing changes in the Arctic regional climate are resulting in increased CH4 emissions. Specifically, we will use these concentration and isotopic data with the p-TOMCAT chemical transport and Met Office NAME models to locate Arctic CH4 sources and quantify any interannual changes in emissions. In addition to these main objectives, we plan to make regular measurements of atmospheric concentrations of other gases (CO2, CO, N2O, SF6, H2, O2/N2 and Ar/N2) from glass bottles collected at several Arctic locations. Such measurements will not require additional collections or costs as they will be made in parallel to the CH4 measurements, improving cost efficiency. Measurement of other gas species will help to assess the linked Arctic processes and source emissions of these gases, both on land and at sea, e.g. fire emissions (increased CO), ocean warming, expansion of oceanic 'dead zone' (due to decreased amounts of dissolved O2) and thawing permafrost soils and wetlands.

Publications

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Berchet A (2016) Atmospheric constraints on the methane emissions from the East Siberian Shelf in Atmospheric Chemistry and Physics

 
Description The Arctic methane budget has been studied, using C isotopes to identify major sources of methane. The results demonstrate that in summer the main Arctic source is from wetland emissions and in winter the major source is leakage from gas systems and human activities. There is no evidence for significant emissions of methane reaching the air from hydrate sources.
Exploitation Route The work has significant implications for those studying hydrates in the Arctic, and in developing models of future Arctic responses to climate change.
The recent Arctic Council AMAP report draws on our work.
Sectors Energy,Environment,Government, Democracy and Justice,Other

 
Description The work on the Arctic methane budget has contributed to a major report collected by Environment Canada in Canada's chairmanship of the Arctic Council. The work has also been reported in the media and to policymakers in the UK. The work has helped initiate a major new Norwegian methane project.
First Year Of Impact 2015
Sector Energy,Environment,Government, Democracy and Justice
Impact Types Cultural,Societal,Economic,Policy & public services

 
Description Report to Arctic Council (AMAP): Co-authorship of major Canadian goverment report on Arctic methane, presented during the Canadian presidency of the Arctic Council. Report is listed in publication list.
Geographic Reach Multiple continents/international 
Policy Influence Type Gave evidence to a government review
Impact Arora et al (2015) Arctic Monitoring and Assessment Program (AMAP) assessment 2015: Methane as a climate forcer. Report by Canadian government to the Arctic Council.
 
Description Atmospheric sampling with the Norwegian Inst. for Air Research (NILU) 
Organisation Norwegian Institute for Air Research
Country Norway 
Sector Charity/Non Profit 
PI Contribution Joint Arctic air sampling at Zeppelin, Spitsbergen and Antarctic sampling at Troll base.
Collaborator Contribution Collaborative isotopic analysis: NILU collect air samples and RHUL analyses them for d13C in methane.
Impact Collaborative papers, reported in publications
 
Description Award winner, 'The Engineer'/EPSRC Collaborate to Innovate awards. 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact Award winner, The Engineer, Innovation prize
Year(s) Of Engagement Activity 2016
URL https://www.theengineer.co.uk/collaborate-to-innovate-winners-annnounced/
 
Description BBC World Service documentary - radio. "Discovery - cheating the atmsophere" 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Participation in BBC World Service documentary "Disocvery - cheating the atmosphere". Long interview on the problems of assessing greenhouse gas emissions inventories for the United Nations Framework Convention on Climate Change - Paris Agreement. Broadcast several times in second week of Dec, 2017
Year(s) Of Engagement Activity 2017
URL http://www.bbc.co.uk/programmes/w3csvpfz
 
Description LONCON3 World Science fiction convention 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Several Activities - all invited.
1. Exhibition of methane measurement "Discover your inner cow" sampling methane in breath.
2. Panel discussion on climate in science fiction
3. Panel discussion on sci fiction and policy.
Year(s) Of Engagement Activity 2014
 
Description NERC UnEarthed Showcase 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact NERC UnEarthed Showcase event, Edinburgh. MOYA presentation on the Global methane budget, focussed on school age students. ~7000 schoolchildren and many members of the general public. 17,18,19 and 20 Novermber 2017
Year(s) Of Engagement Activity 2017
URL http://www.nerc.ac.uk/latest/events/archive/unearthed/
 
Description Public Lecture: 56th Annual Bennett Lecture, Leicester Literary and Philosophical Society 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Public lecture - annual 'named' lecture of the Leicester Literary and Philosophical Society, Univ. of Leicester
Year(s) Of Engagement Activity 2015
URL http://www2.le.ac.uk/hosted/litandphil/documents-1/transactions/transactions_2015
 
Description Royal Holloway Science festival 2015 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Several activities - all coordinated by us;
1. fossil trail
2. Volcano exhibit and eruption
3. lecture
4. Gold panning
Year(s) Of Engagement Activity 2015