Climate feedbacks from wetlands and permafrost thaw in a warming world (CLIFFTOP)

Lead Research Organisation: NERC Centre for Ecology and Hydrology
Department Name: Hydro-climate Risks

Abstract

Carbon dioxide and methane are the most important long-lived greenhouse gases causing global warming and climate change. These two gases, which are the major components of the global carbon cycle, are added to and removed from the atmosphere in a wide range of ways, from both natural and human activities. Wetlands are the largest natural source of methane and methane emissions from wetlands are expected to increase in a warming world. Further, in high northern latitudes, large amounts of carbon are stored in frozen soils or permafrost. The polar regions are warming faster than other parts of the Earth. As these soils warm causing the permafrost to thaw, the stored carbon can be converted by microbial activity over time and released to the atmosphere as carbon dioxide or methane, leading to further warming and hence a positive feedback. Combined with landscape changes, this may lead to the formation of new wetlands resulting in further emissions of methane.

Wetlands and permafrost thaw are therefore important biogeochemical processes that need to be included in models of the Earth's climate. Through their inclusion, climate, or now Earth System, models will then account for the feedbacks that wetlands and permafrost thaw produce on the physical climate system (e.g., on future temperature changes). Following the international climate agreement in 2015 to limit future temperature rises to less than 1.5-2 degrees centigrade above pre-industrial levels, there is an urgent need to quantify this contribution of wetlands and permafrost thaw as this will constrain the accumulated emissions of greenhouse gases that can be released from human activities such as fossil fuel combustion if global temperatures are to be stabilised.

In this study, we will use the UK community state-of-the-art land surface model, the Joint UK Land Environment Simulator (JULES) to model wetlands and permafrost thaw. We plan targeted development of the land-surface model to enhance its capability for considering wetlands, permafrost thaw, methane and carbon dioxide emissions in a more consistent and integrated manner. For this work, we will use this improved version of JULES with a simplified but robust climate emulator, IMOGEN. IMOGEN replicates the behaviour of a wide range of more complex and resource intensive climate and Earth System models that contributed to the latest climate change assessment of the IPCC.

We will undertake model runs with the JULES-IMOGEN modelling system (a) to assess the impact of Arctic carbon releases that are not included in many climate models, (b) to quantify the corresponding climate feedbacks and the impact of these additional emissions on allowed human emissions for 1.5 or 2 degree C climate stabilisations. The research proposed will provide important evidence to support the commitments made in the Paris Agreement to 'strengthen the global response to the threat of climate change.... and to pursue efforts to limit the temperature increase to 1.5 degree C above pre-industrial levels'.

The outputs of the work will include:
* papers for publication in the scientific literature, which will be included in the special IPCC assessment of the IPCC
* wetland methane emission datasets for current day and future conditions that will be of value for the atmospheric modelling community

The project links to and will complement ongoing work at the Met Office, our project partner, for the UK government.

Planned Impact

The key beneficiaries are
(1) policymakers
(2) the scientific research community
(3) UK and international public and school
(4) Arctic communities

(1) Policymakers

The call for this application is explicit that the research will be policy relevant, either nationally or internationally. The research proposed here will contribute strongly to the work of the UN Framework Convention on Climate Change and particularly the Intergovernmental Panel on Climate Change (IPCC). It is our intention to publish the work in the scientific literature and to make it available for inclusion in the special IPCC assessment. We will also use the existing strong links of the Met Office to brief policymakers in the Department of Business, Energy and Industrial Strategy about the work.

This study has a polar focus. The Arctic is a key region in the context of impacts from and the opportunities provided by climate change. We will look to present our work at suitable international conferences on the Arctic to engage with a broader range of non-academic groups. We have contacted and will work with the NERC Arctic Office to identify other opportunities to promote this work.

The international Global Carbon Project (GCP) produces an annual carbon budget (http://www.globalcarbonproject.org/). The GCP has recently started producing global CH4 budgets and our project partner (Met Office) has provided JULES wetland methane emission estimates. We will continue our participation in this activity, which will lead to publications in the scientific literature and will inform future IPCC assessment of the Global Methane cycle.

(2) Scientific research community

The improved modelling of wetlands and permafrost and the resulting emission datasets will be of interest to climate, land surface and atmospheric scientists (see section on Academic Beneficiaries).

(3) UK and international public and schools

There is a thirst in sectors of the UK public for access to the latest science, and a need to motivate schoolchildren about the excitement and importance of environmental science. The Centre for Ecology & Hydrology has a very strong track record in engaging policy makers and the wider public on scientific issues around environmental issues such as those addressed by this project. The research will be advertised to the public through press releases via CEH and NERC's Press Offices.

The Big Bang is a national programme which celebrates Science, Technology, Engineering and Maths. Events in the South West are organised by the Education Business Partnership (South West) and the University of Exeter. We would present our work at the 2017 'Big Bang' exhibition.

(4) Arctic communities

The new NERC project Under-recognized Cold Season and Upland Tundra Arctic Methane Sources has a strong focus on the Alaskan Arctic. We will work with the PI of that project (Oechel, Open University) and contribute to outreach events for the local communities on the North Slope (e.g., seminars organized by the Barrow Arctic Science Consortium).


We will also use relevant impact activities of other NERC-funded (e.g., Global Methane) and international (EU CRESCENDO) projects to enhance the impact of this project.

Publications

10 25 50
 
Description Commissioned as part of the NERC 1.5°C warming programme, this grant investigated the extent to which the release of methane, the second-most important greenhouse gas, from natural sources would reduce the allowable anthropogenic fossil carbon emissions to achieve stabilisation at warming of 1.5°C or 2°C above pre-industrial levels. Wetlands are the largest natural source of methane to the atmosphere and these emissions respond strongly to climate change. A second natural feedback is from permafrost thaw. Permafrost, defined as ground (soil or rock) that remains at or below 0°C for at least two consecutive years, is a significant store of organic carbon. In a warming climate, the resulting microbial decomposition of previously frozen organic carbon is potentially one of the most significant feedbacks from terrestrial ecosystems.

Previous work on the permafrost carbon feedback assumes the carbon in permafrost is released into the active carbon cycle as carbon and thence as carbon dioxide to the atmosphere. Because of its larger greenhouse effect, the inclusion of the methane feedback has the effect of increasing the warming potential of the released carbon and thus reducing the total allowable carbon emissions from human activities. In this study, we find that the methane feedbacks from natural wetlands and permafrost thaw are substantial, causing anthropogenic carbon dioxide emission budgets to be reduced by 9-15% for stabilisation at 1.5°C, and 6-10% for 2.0°C stabilisation.
Exploitation Route The findings were cited in the IPCC Special Report on Global Warming of 1.5°C, which was published in October 2018.

In collaboration with 2 other projects in the NERC warming programme, briefing cards have been prepared on the projects for use with UK policy-makers in BEIS, Defra and with the Climate Change Committee.

The projects were highlighted at a UK side event at the UNFCCC COP24 meeting in Poland in December 2018. Over 200 memory sticks were distributed at the event, containing electronic copies of the briefing cards, information about the projects in the NERC programme with links to papers produced by the projects and copies of the presentation given at the NERC-BEIS workshop held in September 2018.
Sectors Education,Environment

URL https://www.ceh.ac.uk/our-science/projects/understanding-pathways-and-impacts-15c-rise-global-temperature
 
Description The findings of the project have been used as follows: (1) the papers by Comyn-Platt et al. and Collins et al. (see publications section) were cited in the IPCC Special Report on Global Warming of 1.5 °C (http://www.ipcc.ch/report/sr15/); (2) the paper by Comyn-Platt et al. (see publications section) has been made available to the chapter lead authors for the IPCC Special Report on Ocean and Cryosphere; (3) the paper by Harper et al. (see publications section) has been made available to the chapter lead authors for the IPCC Special Report on Land Use; (4) the work was cited in a report on the NERC 1.5 Warming programme that is being prepared for the UK Department for Business, Energy & Industrial Strategy by the University of East Anglia (see also section on Influence on Policy ....) (5) the project and its findings were presented to policymakers from across the UK government and Devolved Administrations at a NERC-BEIS workshop held on the NERC 1.5°C Warming programme
First Year Of Impact 2018
Sector Environment
Impact Types Policy & public services

 
Description Citation in IPCC Special Report on Global Warming of 1.5 °C
Geographic Reach Multiple continents/international 
Policy Influence Type Citation in other policy documents
URL http://www.ipcc.ch/report/sr15/
 
Description The Tyndall Centre for Climate Change Research at the University of East Anglia produced a report for the Department for the UK Department for Business, Energy and Industrial Strategy (BEIS). The report summarises research examining the implications of global warming of 1.5°C and 2°C, which were funded by (1) BEIS and conducted by researchers at the Tyndall Centre and collaborators, and (2) the Natural Environment Research Council (NERC) and conducted by researchers at various universities and research centres. The report addressed a series of questions proposed by BEIS.
Geographic Reach National 
Policy Influence Type Citation in other policy documents
URL https://tyndall.ac.uk/sites/default/files/implications_of_global_warming_of_1.5_and_2_degrees_-_fina...
 
Description 1.5 Warming Programme
Amount £50,000 (GBP)
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 10/2017 
End 03/2018
 
Title CMIP5 GCM-based monthly patterns of local meteorological change, per degree of mean land warming, for driving the IMOGEN impacts model 
Description This dataset consists of monthly spatial patterns of meteorological change for 34 Global Circulation Models (GCMs). The patterns are a set of regression coefficients, each representing the change per degree of mean global warming over land, for the corresponding meteorological variable. The meteorological variables analysed for each GCM include: surface temperature change per degree global warming (K K-1); surface relative humidity change per degree global warming (percentage of K-1); wind change per degree global warming (m s-1 K-1); longwave change per degree global warming (W m-2 K 1); shortwave change per degree global warming (W m-2 K-1); precipitation change per degree global warming (mm day-1 K-1) and pressure change per degree global warming (hPa K-1). 
Type Of Material Database/Collection of data 
Year Produced 2018 
Provided To Others? Yes  
Impact The datasets were critical to the work undertaken under this and 2 others projects (CLUES and MOC1.5) of the NERC 1.5 Warming programme 
URL https://catalogue.ceh.ac.uk/documents/343885af-0f5e-4062-88e1-a9e612f77779
 
Title Natural wetland methane and permafrost thaw feedback modelling with JULES-IMOGEN (1850-2100) 
Description These data contain 408 instances of annual model output from JULES/IMOGEN simulations, covering the period between 1850-2100. Each simulation (which corresponds to one netcdf file) provides annual average of carbon stocks of the land, atmosphere and ocean store required to calculate the anthropogenic fossil fuel emissions as the residual of the yearly changes. Also included are the global warming variables, fractional land-cover, natural wetland extent and methane (CH4) flux and the soil temperature and moisture content for additional analysis. 
Type Of Material Database/Collection of data 
Year Produced 2018 
Provided To Others? Yes  
Impact These are key model outputs used to support a paper published on the work (Comyn-Platt et al., 2018: see Publications section) 
URL https://catalogue.ceh.ac.uk/documents/1cebd79c-02e7-475a-a1da-1f26a963d41e
 
Description CLIFFTOP-CLUES-MOC1.5 
Organisation University of Exeter
Department College of Engineering, Mathematics & Physical Sciences
Country United Kingdom 
Sector Academic/University 
PI Contribution The CEH team developed a novel inverse version of the IMOGEN climate emulator coupled to the JULES land surface model and created the agreed baseline configuration that the CLIFFTOP (CEH), CLUES (Exeter) and MOC1.5 (Reading) projects would use for the NERC 1.5°C Warming programme.
Collaborator Contribution The University of Exeter provided expertise and data on land use change and the land use scenarios involving (i) biomass energy with carbon capture and storage; (ii) afforestation and reforestation. The Exeter group also provided expertise to both CLIFFTOP and MOC1.5 about the ozone impact on vegetation. The University of Reading provided expertise and data on projections of anthropogenic methane emissions and the tropospheric chemistry of methane leading to the formation of ozone (which affects vegetation).
Impact Shared analysis of the various model runs, which led to the publication of 3 papers.
Start Year 2016
 
Description CLIFFTOP-CLUES-MOC1.5 
Organisation University of Reading
Department Department of Meteorology
Country United Kingdom 
Sector Academic/University 
PI Contribution The CEH team developed a novel inverse version of the IMOGEN climate emulator coupled to the JULES land surface model and created the agreed baseline configuration that the CLIFFTOP (CEH), CLUES (Exeter) and MOC1.5 (Reading) projects would use for the NERC 1.5°C Warming programme.
Collaborator Contribution The University of Exeter provided expertise and data on land use change and the land use scenarios involving (i) biomass energy with carbon capture and storage; (ii) afforestation and reforestation. The Exeter group also provided expertise to both CLIFFTOP and MOC1.5 about the ozone impact on vegetation. The University of Reading provided expertise and data on projections of anthropogenic methane emissions and the tropospheric chemistry of methane leading to the formation of ozone (which affects vegetation).
Impact Shared analysis of the various model runs, which led to the publication of 3 papers.
Start Year 2016
 
Description Distribution of project outputs at the UNFCCC COP24 meeting 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Policymakers/politicians
Results and Impact The CLIFFTOP, CLUES and MOC1.5 projects were presented at a UK side event, held during the UNFCCC COP24 meeting (Poland, December 2018). 200 Memory sticks containing a briefing card on each of the 3 projects, together with information on the other projects in the NERC Warming programme, were distributed at this side event.
Year(s) Of Engagement Activity 2018
URL https://www.ceh.ac.uk/our-science/projects/understanding-pathways-and-impacts-15c-rise-global-temper...
 
Description Workshop for UK Government on the NERC 1.5°C Warming Programme 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Policymakers/politicians
Results and Impact As part of the Paris Agreement, the Intergovernmental Panel on Climate Change (IPCC) was asked to prepare a special report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emissions pathways. The Natural Environment Research Council (NERC) and the Department for Business, Energy & Industrial Strategy (BEIS) funded a research programme in 2016 (http://gotw.nerc.ac.uk/list_them.asp?them=One+and+a+Half+Degrees&cookieConsent=A) to inform the IPCC special report and /or UK domestic climate policy.

The Centre for Ecology & Hydrology (CEH), the Universities of Exeter and Reading and BEIS organised a workshop in September 2018 to brief UK government policy-makers on the project outputs from the NERC-BEIS programme. The workshop was timely as it was held during the final government review of the IPCC Special Report on 1.5°C Warming. The workshop was attended by 45 participants from the academic research and policy communities. All 10 of the funded NERC Warming projects gave presentations of the key findings and policy-relevant outcomes of the research. Short presentations of related research were also given.
Year(s) Of Engagement Activity 2018
URL https://www.ceh.ac.uk/news-and-media/blogs/understanding-pathways-and-impacts-rise-global-temperatur...