Monday, 07 December 2020
Preserving the world's peatlands – and the vast carbon stores they contain – is vital to limiting climate change, researchers say.
The study, led by the University of Exeter and Texas A&M University, in collaboration with the University of Nottingham, examines peatland losses over the course of human history and predicts these will be "amplified" in the future.
Peatlands are expected to shift from an overall "sink" (absorbing carbon) to a source this century, primarily due to human impacts across the tropics, and the study warns more than 100 billion tons of carbon could be released by 2100, although uncertainties remain large.
Peatlands are currently excluded from the main Earth System Models used for climate change projections – something the researchers say must be urgently addressed.
"Peatlands contain more carbon than all the world's forests and, like many forests, their future is uncertain," said Professor Angela Gallego-Sala, of Exeter's Global Systems Institute.
"Peatlands are vulnerable to climate change impacts such as increased risk of wildfires and droughts, the thawing of permafrost and rising sea levels.
"However, the main threats to peatlands are more direct – particularly destruction by humans to create agricultural land.
"So the future of peatlands is very much in our hands."
Peatlands are a type of wetland found in almost every country on Earth, currently covering 3% of the global land surface.
Professor Gallego-Sala says they have been "overlooked" in some climate models because they are seen as "inert" – neither absorbing nor emitting carbon at a rapid rate when left alone.
This exclusion from models makes it hard to estimate future changes, so the study combined existing research with survey estimates from 44 leading peatland experts, including Professor David Large, Head of Chemical and Environmental Engineering and Professor Sofie Sjogersten, from the School of Biosciences at the University of Nottingham.
Based on this, it estimates total carbon loss from 2020-2100 at 104 billion tons.
Previous research by Professor David Large, from the Department of Chemical and Environmental Engineering at the University of Nottingham informed the Exeter study. With expertise of how peatland behaves over days to millions of years, Professor Large was also an author on the paper.
“Peatlands are a major and potentially vulnerable global carbon store. Under future climate change what will happen to this vast carbon store is uncertain. Peatlands need to be included in future climate models and more work is required.”
Professor Sjogerston said: “Preserving the world’s peatlands, including the ones discovered more recently in the Amazon and Congo is vital to limit climate change, and we can collectively reduce peatland destruction and conversion by implementing sustainable practices and effective policies as soon as possible.”
The authors stress this estimate is highly uncertain (losses up to 360 billion tons to gains of 103 billion tons) – but it demonstrates the need both for inclusion in models and better peatland preservation.
"Even though we would like more information, we clearly need to make decisions now about how we manage these ecosystems," Dr Gallego-Sala said.
"We simply can't afford for peatlands to go up in smoke."
New “discoveries” of tropical peatlands in the Amazon and Congo are mainly intact, and the researchers say it is important to make sure we have solid policies in place.
"We have a responsibility to find a way forward that works for people and the planet," Dr Gallego-Sala said.
"Where people have a strong economic incentive – or even necessity – to destroy peatlands, we need plans and policies that offer more sustainable alternatives."
The international research team included the universities of Helsinki and Quebec.
Funders included the PAGES (Past Global Changes) project, the International Union for Quaternary Research (INQUA) and the Natural Environment Research Council (NERC).
The paper, published in the journal Nature Climate Change, is entitled: "Expert assessment of future vulnerability of the global peatland carbon sink."
Story credits
More information is available from Professor David Large, on david.large@nottingham.ac.uk or Emma Lowry, Media Relations Manager (Engineering) on 0115 84 67156 or emma.lowry@nottingham.ac.uk
Notes to editors:
About the University of Nottingham
Ranked 32 in Europe and 16th in the UK by the QS World University Rankings: Europe 2024, the University of Nottingham is a founding member of the Russell Group of research-intensive universities. Studying at the University of Nottingham is a life-changing experience, and we pride ourselves on unlocking the potential of our students. We have a pioneering spirit, expressed in the vision of our founder Sir Jesse Boot, which has seen us lead the way in establishing campuses in China and Malaysia - part of a globally connected network of education, research and industrial engagement.
Nottingham was crowned Sports University of the Year by The Times and Sunday Times Good University Guide 2024 – the third time it has been given the honour since 2018 – and by the Daily Mail University Guide 2024.
The university is among the best universities in the UK for the strength of our research, positioned seventh for research power in the UK according to REF 2021. The birthplace of discoveries such as MRI and ibuprofen, our innovations transform lives and tackle global problems such as sustainable food supplies, ending modern slavery, developing greener transport, and reducing reliance on fossil fuels.
The university is a major employer and industry partner - locally and globally - and our graduates are the second most targeted by the UK's top employers, according to The Graduate Market in 2022 report by High Fliers Research.
We lead the Universities for Nottingham initiative, in partnership with Nottingham Trent University, a pioneering collaboration between the city’s two world-class institutions to improve levels of prosperity, opportunity, sustainability, health and wellbeing for residents in the city and region we are proud to call home.
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