Peatlands and the global Carbon cycle during the past millennium: a global assessment using observations and models

Lead Research Organisation: University of Exeter
Department Name: Geography

Abstract

Future climate change is one of the most challenging issues facing humankind and an enormous research effort is directed at attempting to construct realistic projections of 21st century climate based on underlying assumptions about greenhouse gas emissions. Climate models now include many of the components of the earth system that influence climate over a range of timescales. Understanding and quantifying earth system processes is vital to projections of future climate change because many processes provide 'feedbacks' to climate change, either reinforcing upward trends in greenhouse gas concentrations and temperature (positive feedbacks) or sometimes damping them (negative feedbacks). One key feedback loop is formed by the global carbon cycle, part of which is the terrestrial carbon cycle. As carbon dioxide concentrations and temperatures rise, carbon sequestration by plants increases but at the same time, increasing temperatures lead to increased decay of dead plant material in soils. Carbon cycle models suggest that the balance between these two effects will lead to a strong positive feedback, but there is a very large uncertainty associated with this finding and this process represents one of the biggest unknowns in future climate change projections. In order to reduce these uncertainties, models need to be validated against data such as records for the past millennium. Furthermore, it is extremely important to make sure that the models are providing a realistic representation of the global carbon cycle and include all its major component parts. Current models exclude any consideration of the reaction of peatlands to climate change, even though these ecosystems contain almost as much carbon as the global atmosphere and are potentially sensitive to climate variability. On the one hand, increased warmth may increase respiration and decay of peat and on the other hand, even quite small increases in productivity may compensate for this or even exceed it in high latitude peatlands. A further complication is that peatlands emit quite large quantities of methane, another powerful greenhouse gas. Our proposed project aims to assess the contribution of peatlands to the global carbon cycle over the past 1000 years by linking together climate data and climate model output with models that simulate the distribution and growth of peatlands on a global scale. The models will also estimate changes in methane emissions from peatlands. In particular, we will test the hypotheses that warmth leads to lower rates of carbon accumulation and that this means that globally, peatlands will sequester less carbon in future than they do now. We will also test whether future climate changes lead to a positive or negative feedback from peatland methane emissions. To determine how well our models can simulate the peatland-climate links, we will test the model output for the last millennium against fossil data of peat growth rates and hydrological changes (related to methane emissions). To do this, we will assemble a large database of published information but also new data acquired in collaboration with partners from other research organisations around the world who are involved in collecting information and samples that we can make use of once we undertake some additional dating and analyses. Once the model has been evaluated against the last millennium data, we will make projections of the future changes in the global carbon cycle that may occur as a result of future climate change. This will provide a strong basis for making a decision on the need to incorporate peatland dynamics into the next generation of climate models. Ultimately we expect this to reduce uncertainty in future climate change predictions.

Publications

10 25 50
 
Description We have quantified carbon accumulation for a range of peatalnds and published extensively on individual areas during the main period of the grant. We have now completed a global synthesis of data and a major paper has been published in Nature Climate Change. The paper shows that there is a global relationship between peatland carbon accumulation and light availabuility during the growing season that enables us to begin to predict how the global peatland carbon store will change under future climate changes. We show that the global peatland carbon sink will increse over the next century and remain positive but gradually decline in magnitude after AD 2100. We have contributed to a large number of other regional studies with research groups from around the world, using the data colected through the project. We have undertaken further pilot work and now received further funding to explore the potential for an increased carbon sink in the Arctic, and work started in summer 2019.
Exploitation Route There is an extensive database for peatland carbon that can be used for further work in global modeling efforts. This is available and being actively used by the PAGES C_PEAT working group, coordinated by CoI Gallego Sala and a colleague in the US.
Sectors Environment

 
Description Our work has stimulated debate on the distribution of peatlands and the relationship between carbon storage and climate. In particular, it has been used to establish preinciples and priorities for peatland restoration and preservation.
First Year Of Impact 2012
Sector Environment
Impact Types Societal,Policy & public services

 
Description Fullbright Summer School
Geographic Reach Multiple continents/international 
Policy Influence Type Influenced training of practitioners or researchers
Impact The fullbright Climate change Summer School is run at the University of Exeter and attracts undergraduate and postgraduate students from a range of disciplines. Angela Gallego-Sala has been teaching a module focussed on the importance of peatlands as ecosystem service providers, including the role of peatlands in the carbon cycle.
 
Description UK Climate Change Committees - peatland restoration enquiry
Geographic Reach Asia 
Policy Influence Type Citation in other policy documents
Impact The research has informed the development of the UK Peatland Code, which is leading the way for the development of payment for ecosystem services programmes in the UK.
URL http://www.iucn-uk-peatlandprogramme.org/sites/all/files/Review%20Peatland%20Historic%20Environment,...
 
Description Undergraduate course GEO3232 Peatland Ecosystems - delineating fate of peatlands, including Arctic peatlands, in the future
Geographic Reach National 
Policy Influence Type Influenced training of practitioners or researchers
Impact Increased awareness of the importance of peatlands and effects of warming in the Arctic for the University of Exeter Geography student cohort.
 
Description Research Fellowship
Amount € 195,455 (EUR)
Funding ID EU project 658041 
Organisation Marie Sklodowska-Curie Actions 
Sector Charity/Non Profit
Country Global
Start 03/2016 
End 02/2018
 
Description Small Royal Society grant
Amount £15,000 (GBP)
Funding ID RG160877 
Organisation The Royal Society 
Sector Charity/Non Profit
Country United Kingdom
Start 03/2017 
End 03/2019
 
Description Effects of permafrost aggradation on peat properties as determined from a pan-Arctic synthesis of plant macrofossils 
Organisation University of Alaska Fairbanks
Country United States 
Sector Academic/University 
PI Contribution The research team contributed data compiled through the project to a wider compilation of a pan-arctic synthesis to examine the effect of permafrost aggradation on peat properties.
Collaborator Contribution Our partners led the synthesis and put the wider team of peatland scientists together. They analysed the data and lead the publication.
Impact The main output was a publication entitled "Effects of permafrost aggradation on peat properties as determined from a pan-Arctic synthesis of plant macrofossils" on Journal of Geophysical Research: Biogeosciences, detailing the findings of the synthesis. the DOI is 10.1002/2015JG003061
Start Year 2015
 
Description Global-scale pattern of peatland Sphagnum growth driven by photosynthetically active radiation and growing season length 
Organisation Lehigh University
Country United States 
Sector Academic/University 
PI Contribution Collaboration with Dr Julie Louisel has lead to the publication of an article in Biogeosciences (doi:10.5194/bg-9-2737-2012).
Start Year 2011
 
Description NSF project on Holocene peat C accumulation records 
Organisation Bowdoin College
Country United States 
Sector Academic/University 
PI Contribution Involvement as collaborators in the project entitled "Holocene peat C accumulation records" funded by the National Science Foundation in the U.S.A. Principal investigators in the grant are Prof. Zicheng Yu of Lehigh University, Philip Camill of Bowdoin College and Prof Dave Beilman of University of Hawaii. Prof D. Charman has been invited to co-edit a special issue in "Holocene" on peatland research.
Start Year 2012
 
Description NSF project on Holocene peat C accumulation records 
Organisation Lehigh University
Country United States 
Sector Academic/University 
PI Contribution Involvement as collaborators in the project entitled "Holocene peat C accumulation records" funded by the National Science Foundation in the U.S.A. Principal investigators in the grant are Prof. Zicheng Yu of Lehigh University, Philip Camill of Bowdoin College and Prof Dave Beilman of University of Hawaii. Prof D. Charman has been invited to co-edit a special issue in "Holocene" on peatland research.
Start Year 2012
 
Description NSF project on Holocene peat C accumulation records 
Organisation University of Hawaii
Country United States 
Sector Academic/University 
PI Contribution Involvement as collaborators in the project entitled "Holocene peat C accumulation records" funded by the National Science Foundation in the U.S.A. Principal investigators in the grant are Prof. Zicheng Yu of Lehigh University, Philip Camill of Bowdoin College and Prof Dave Beilman of University of Hawaii. Prof D. Charman has been invited to co-edit a special issue in "Holocene" on peatland research.
Start Year 2012
 
Description Sensitivity of peatland carbon loss to organic matter quality 
Organisation Agroscope
Department Reckenholz-Tänikon Research Station (ART)
Country Switzerland 
Sector Public 
PI Contribution Collaboration with Dr J. Leifeld, lead to the publication on an article in Geophysical Research Letters.
Start Year 2011
 
Description AGU poster presentation: Hydrological reconstruction for the last millenium 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Poster sparked questions and possible future collaborations

Possible future collaborations
Year(s) Of Engagement Activity 2013
 
Description Blanket bogs need protection from climate change 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Phys Org presented the press release of the blanket bog article published in Nature Climate Change

After this review was published on-line, I had a lot of interest in receiving copies of the article.
Year(s) Of Engagement Activity 2012
 
Description Chinese State Key Laboratory for Soils and Sustainable Agriculture - blanket bogs 
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 Professional Practitioners
Results and Impact The blanket bog article has been reviewed by the Chinese State Key Laboratory for Soils and Sustainable Agriculture and a link to the full article added to their website.

Chinese scientists have requested the dataset behind the publication and collaborations have come out of this review.
Year(s) Of Engagement Activity 2013
URL http://english.issas.cas.cn/rh/rd/200908/t20090827_34421.html
 
Description Climate change threatens blanket bogs 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Planet Earth online published a review of the blanket bog manuscript published in Nature Climate Change.

A review of the article pubished in Nature Climate Change on the effect of climate change on blanket bog global extent was published on-line by Planet Earth. Tom Marshall interviewed A. Gallego-Sala over the phone, when they discussed the article extensively. After this article was published, I received further requests to share my article.
Year(s) Of Engagement Activity 2012
URL http://planetearth.nerc.ac.uk/news/story.aspx?id=1288
 
Description Hawaii invited talk 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact Tropical peatland workshop at Univeristy of Hawaii at Manua Loa. Invited talk at a workshop on the results of the millipeat project especifically around tropical peatlands. This will lead to future collaborations and research efforts on tropical peatlands.
Year(s) Of Engagement Activity 2017
 
Description Holocene C accumulation workshop at Lehigh 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Talk about our experience in the Millipeat project informed the Holocene collaborative project.

International colleagues became aware of our project and offered to share data
Year(s) Of Engagement Activity 2013
 
Description India Environment Portal - blanket bogs threatened 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact A brief review and a link to the article on blanket bogs is available in India via the India Environment Portal. http:// http://www.indiaenvironmentportal.org.in/feature-article/blanket-peat-biome-endangered-climate-change




After the review was published, I got contacted by email to get a copy of the article.
Year(s) Of Engagement Activity 2013
 
Description Invited talk at Leeds University 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Professional Practitioners
Results and Impact The talk sparked questions and discussion afterwards.

A Chinese colleague who was visiting Leeds showed intersest in our project, and wanted to collaborate with us.
Year(s) Of Engagement Activity 2014
 
Description Invited talk at Manchester University: Peatlands during the last millennium - a global synthesis using observations and models 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Professional Practitioners
Results and Impact The talk sparked questions and discussion afterwards. I strengthen collaboration possibilities with colleagues at Manchester.

Young scientists in particular, approached me for discussion of results right after the talk, and further contacted me by email.
Year(s) Of Engagement Activity 2014
 
Description Invited talk at Northeast Normal University, Changchung, China, June 2019 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Invited talk at Northeast Normal University, Changchung, China, June 2019. There were mainly undergraduate and postgraduate students, together with more senior academics. There were lots of questions and discussion afterwards. It has led to new collaborations with colleagues in China.
Year(s) Of Engagement Activity 2019
 
Description Invited talk at Plymouth University 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Professional Practitioners
Results and Impact An invited talk at Plymouth University - covering both results of the "Peatlands and the global Carbon cycle during the past millennium: a global assessment using observations and models" project and the new ICAAP project.
Year(s) Of Engagement Activity 2020
 
Description Invited talk, University of Helsinki, Sept 2018 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact An invited talk in Helsinki University, to present the results of the Peatlands and the global Carbon cycle during the past millennium: a global assessment using observations and models project. The audience asked many questions and a discussion resulted.
Year(s) Of Engagement Activity 2018
 
Description Joint BES / IUCN UK Peatland Programme Symposium 2012 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Type Of Presentation keynote/invited speaker
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact The preliminary findings of the project and previous NERC funded projects were presented in the IUCN Symposium, at University of Bangor, 26 - 28 June 2012, where policy makers and peatland managers were present.

A Gallego-Sala was an invited speaker at the BES/IUCN peatlands symposium in Bangor. After my talk, a lot of intersest was sparked on the findings, and decision makers came to talk to me and ask me questions.
Year(s) Of Engagement Activity 2012
 
Description Keynote at AGU December 2019 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact An invited talk at AGU (B22F-01 Planetary Drivers of Carbon Accumulation in Peatlands (Invited) ). There were Q&As after the talk. New discussions around the results of the project.
Year(s) Of Engagement Activity 2019
URL https://agu.confex.com/agu/fm19/meetingapp.cgi/Session/87470
 
Description Keynote at the Quaternary Research Association Annual Meeting in Leeds, January 2020 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact A keynote at the Quaternary Research Association Annual Meeting. The talk was about the peatland carbon sink (results from the Peatlands and the global Carbon cycle during the past millennium: a global assessment using observations and models project were presented) but also about what questions remain unanswered (ICAAP project). The audience was made up of scientists, but also members of the public and practitioners.
Year(s) Of Engagement Activity 2020
URL https://qraleeds2020.com/
 
Description Peatlands and Climate Change - lecture 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Postgraduate students
Results and Impact Lecture given to undergraduates at Bristol University

After the talk, many students contact me for further information.
Year(s) Of Engagement Activity 2011,2012,2013,2014
 
Description Penryn - Indonesian peatlands and fire 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact A workshop with Indonesian politicians, managers and scientists to spark collaborations between University of Exeter and Indonesian institutions.
Year(s) Of Engagement Activity 2017
 
Description Quaternary Research Invited Talk - University of Cambridge Nov 2017 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact An invited talk to the Quaternary Association in Cambridge University. The audience was mixed, with undergraduates, postgraduates and diverse mix of scientists. Q&A followed.
Year(s) Of Engagement Activity 2017
 
Description Soapbox Science 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact - We had lots of people asking questions, both children and adults.
- People engaged with the "props" I used, these included sphagnum moss, peat cores, and a layered cake that people could "core" with straws.

After my talk, families wanted to know more about where I worked, and what we do at the University. Lots of them were fascinated by the idea of time encapsulated in peat.
Lots of people were interested in the event, the best part of it was that mostly people did not realise all of the scientists were women, i.e. that they did not expect science to belong exclusively to men. This was the most important outcome for me.
Year(s) Of Engagement Activity 2015
URL http://soapboxscience.org/
 
Description Video on the global carbon cycle for A-level students 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact An educational video "The short-term carbon cycle" has been made by Time for Geography (https://timeforgeography.co.uk/) in which Angela Gallego-Sala was one of the writers and presented peatland-related content (https://timeforgeography.co.uk/videos_list/carbon-cycle/short-term-carbon-cycle/).

The video has only just been released, so no impact has been recorded.
Year(s) Of Engagement Activity 2019
URL https://timeforgeography.co.uk/videos_list/carbon-cycle/short-term-carbon-cycle/