Carbon Cycling Linkages of Permafrost Systems [CYCLOPS]

Lead Research Organisation: University of Edinburgh
Department Name: Sch of Geosciences

Abstract

Terrestrial ecosystems currently absorb one quarter of the carbon dioxide released by fossil fuel burning into the atmosphere, and thus reduce the rate of climate change. As conditions become more favourable for plant growth, most models predict that high latitudes will take up more carbon during the 21st century. However, vast stores of carbon are frozen in boreal and arctic permafrost, and warming may result in some of this carbon being released to the atmosphere. The recent inclusion of permafrost thaw in large-scale model simulations has suggested that the permafrost feedback is potentially so significant that it could reduce substantially the predicted global net uptake of carbon by terrestrial ecosystems during the 21st century, with major implications for the rate of climate change.
Large uncertainties remain in predicting rates of permafrost thaw and in determining the impacts of thaw in contrasting ecosystems, with many of the key processes missing from carbon-climate models. Firstly, the role that different plant communities play in insulating soils and protecting permafrost is poorly quantified, with key groups such as mosses absent in most models. In addition, fire disturbance can substantially accelerate permafrost thaw, and hence the ability of permafrost-protecting plant communities to recover from fire may play a key role in determining permafrost resilience. Secondly, different ecosystems may respond differently to thaw with contrasting effects on release of greenhouse gasses. In free-draining ecosystems, thaw may result in the net release of carbon due to increased decomposition of previously frozen organic matter. On the other hand, when thawing takes place in peatlands, soil subsidence can effectively raise the water table, which could result in carbon accumulation. However, this potential negative feedback may be offset by enhanced release of the more powerful greenhouse gas, methane. Importantly, the full range of feedbacks to permafrost thaw in these contrasting ecosystems is not currently reflected in process-based models.
To address these issues, we will undertake directed fieldwork campaigns to determine (1) the role that different plant communities play in protecting permafrost within different soil types, and in unburned and fire-disturbed ecosystems, and (2) the impacts of permafrost thaw on fluxes of carbon dioxide and methane in free-draining versus peatland systems. Through links to Canadian partners, data will be collected from a range of field sites where permafrost monitoring is ongoing, including: (i) two contrasting boreal peatlands differing in permafrost extent, and where there is permafrost degradation; (ii) burnt and unburned sites within three important forest types in boreal Canada. Data will be provided from burnt and unburned moist acidic tundra within the continuous permafrost zone in Alaska by our US partners. The spatially variable vegetation recovery at the fire sites allows relationships between vegetation and permafrost to be tested in detail, while comparisons between the tundra, forest and peatland sites provide insights into the impacts of permafrost thaw in contrasting ecosystems.
Critically, these data will be used to develop, parameterise and evaluate a detailed process-based model of vegetation-soil-permafrost interactions. The in-depth representation of vegetation-permafrost linkages will improve predictions of rates of permafrost thaw. The model will be the first to simulate the full range of biogeochemical feedbacks (methane and carbon dioxide) in free-draining versus wetland ecosystems. Furthermore, through links with Met Office scientists, our model will be coupled to the Joint UK Land Environment Simulator (JULES), allowing regional simulations to be run, coupled to a climate model. Ultimately, our project will improve predictions of both the rates and consequences of permafrost thaw, and help determine the potential impacts on 21st century climate change.

Planned Impact

We aim to improve predictions of the rate and consequences of permafrost thaw, including feedbacks to climate. Therefore, the outputs of this research will be of interest to stakeholders in the Arctic, and policy makers nationally and internationally, as well as the general public.
Land managers and governmental organisations such as Natural Resources Canada (NRC) and the Department of Indian Affairs and Northern Development (DIAND) have mandates to preserve the natural environment. Through our contacts (partners Wolfe and Kokelj) we have constructed key parts of our proposal to build on and extend NRC and DIAND research. Our project outputs will benefit these organisations in understanding permafrost systems and carbon cycling, with this being of heightened benefit to them given that our work will occur within, and extend, their framework of ongoing monitoring. We will visit NRC and DIAND partners to strengthen our relationship with the Canadian government and to increase the impact of our project for Canadian partners. We will contribute our data to their databases, and work with our partners to implement a knowledge exchange plan. Our project partners have been involved since the initiation of the proposal and will join us on our field work, including our preparatory field visits, ensuring optimum benefit of our work to them.
Our links with the UK Met Office (see Academic Beneficiaries) means that our findings will be incorporated into coupled climate-carbon cycle modelling, and thus influence predictions of 21st century climate change. This link will maximise the impact of work in terms of its relevance to the Intergovernmental Panel on Climate Change and international policy makers.
Our work will be of interest to communities concerned about sustainability of their way of life, water resources, and changes to permafrost and thermokarst. We will engage with local communities in Canada, to explain our research and to learn more about their views on, and experiences with, climate change. We will inform the public of our activities through information displays and talks at the Yellowknife Northern Heritage Centre and Yukon College at Whitehorse.
The subject area lends itself well to engagement of public interest, and will be an excellent opportunity to promote NERC science in the UK. The public are interested in high latitude ecosystems (e.g. BBC Frozen Planet series), and there is increasing reporting of permafrost issues in the media. The PI and Co-Is are committed to communicating science to the general public. For instance, we had a successful exhibit at the Royal Society Summer Exhibition (2007) on arctic warming. The Impact funding will also allow us to enhance our schools and museum outreach. These activities will include new presentations and development of mobile stands that can be used at museums (we already have good outreach experience with these) and with SciFun, the Scottish Science and Technology Roadshow. In addition, the PDRAs will visit local schools to explain their research, and promote science as a career. We will use the communication offices of our institutions to inform local and national media of our major findings.
Finally, a project website will be established to communicate project outcomes to key stakeholders and the public. We will include videos and footage from field sites and social networking technologies, including experiments with twitter to facilitate broad dissemination.
In summary, together with our plans for academic dissemination, our impact plan will ensure our results have the maximum impact in improving the representation of permafrost in IPCC-facing, coupled climate-C-cycle modelling. We will outline our findings to local government organisations through lectures and through links with our project partners. Furthermore, we will use various media, and museum, school and college outreach activities, to ensure that our research reaches wider society in the UK and Canada.

Publications

10 25 50
publication icon
Bloom AA (2016) The decadal state of the terrestrial carbon cycle: Global retrievals of terrestrial carbon allocation, pools, and residence times. in Proceedings of the National Academy of Sciences of the United States of America

 
Description We have demonstrated that mosses strongly influence carbon uptake and retention in Arctic dwarf shrub vegetation. Our research shows that Arctic models must included mosses to accurately represent ecosystem C dynamics.
We have shown a limited contribution of permafrost carbon to methane release from thawing peatlands.
With international partners, we have summarised and compared carbon fluxes across Arctic tundra, and produced recommendations on how to reduce uncertainty on these estimates.

We have shown why light use efficiency (the rate of photosynthesis per absorbed light) in arctic shrub canopies alters depending on illumination.

We have shown how vegetation interacts with permafrost thaw across boreal landscapes.

We have described and quantified the ecological interactions with permafrost thaw across a range of boreal ecosystem in Canada.

We have developed a mechanistic model of permafrost thaw and evaluated the model across ecological gradients. We have evaluated the degree of and determinants of ecological protection of permafrost.
Exploitation Route Our findings will be used to inform developments of the UK land surface model, JULES. This effort will help the Met Office to better improve simulations of permafrost thaw.
Sectors Environment

URL http://www.geos.ed.ac.uk/cyclops/
 
Description We have used our findings to explain the environmental impacts of global change on permafrost thaw, with presentations in Canada and the UK to schools and the public.
First Year Of Impact 2014
Sector Education
Impact Types Societal

 
Title CARDAMOM panarctic retrievals 2000-2015 
Description Pan Arctic estimates of C cycling at 1 degree resolution, from 2000-2015, at monthly resolution with confidence intervals. 
Type Of Material Database/Collection of data 
Year Produced 2018 
Provided To Others? Yes  
Impact This results underpin a publication by Lopez-Blanco et al. 
URL http://datashare.is.ed.ac.uk
 
Title DALEC2 
Description Data assimilation linked ecosystem carbon model - an intermediate complexity model of the terrestrial carbon cycle. 
Type Of Material Computer model/algorithm 
Year Produced 2015 
Provided To Others? Yes  
Impact DALEC is a core component of the CARDAMOM carbon-data model framework 
 
Title DecoChem v1.0 and DecoBio v1.0 models 
Description Two models of litter and soil carbon decomposition 
Type Of Material Computer model/algorithm 
Year Produced 2014 
Provided To Others? Yes  
Impact Insights into differing sensitivity of biological versos chemical models of organic matter decomposition 
URL https://www.geosci-model-dev.net/7/1519/2014/gmd-7-1519-2014-supplement.pdf
 
Description Our Dynamic Earth, EISF 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact A debate on global change as part of the Edinburgh International Science Festival
Year(s) Of Engagement Activity 2017
 
Description Poster presentation (North Slave Science Showcase) 
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 Members of the Canadian public attended a science showcase in Yellowknife, and viewed our poster

We responded to a request from Aurora College for display material. They reported significant interest, and the poster may also be displayed in Inuvik,.
Year(s) Of Engagement Activity 2014