7 - Demonstrating the vulnerability of upland peatland ecosystems to climate change
Submitting Institution
Imperial College LondonUnit of Assessment
Biological SciencesSummary Impact Type
EnvironmentalResearch Subject Area(s)
Earth Sciences: Physical Geography and Environmental Geoscience
Environmental Sciences: Environmental Science and Management
Summary of the impact
UK upland peatlands constitute the world's greatest area of blanket bog,
an endangered biome, and are the UK's largest natural habitat, carbon
store, and pure water resource. The multi-institutional project "Climate
Change Impacts on UK Upland Soils" identified models to predict the
response of blanket bog to climatic and environmental changes and drew the
attention of diverse stakeholders to the challenge of conserving these
peatlands in a warming climate. The results have had impact on public
policy and the environment by stimulating and informing debate. Since
2011, they have been (i) used by local and national agencies such as the
Forestry Commission, (ii) included in the UK Climate Change Risk
Assessment, (iii) cited by the International Union for Conservation of
Nature (IUCN) Commission of Enquiry on Peatlands, and (iv) used in
evidence for policy making by Defra and the Scottish Parliament.
Underpinning research
Statistical and process-based models were used to predict the
distribution of blanket peat in Britain today, and to project its future
distribution under climate change scenarios obtained from the UK Climate
Impacts Programme. All models could predict accurately the present
distribution and all agreed that the area suitable for blanket peat to
form will shrink to a core area in NW Britain, the degree of shrinkage
depending on the severity of the scenario. High-end climate change
scenarios reduce this core area to a limited region of NW Scotland,
whereas low-end scenarios are less drastic but go in the same direction.
Modelling also showed, however, that extant peatland areas could continue
to exist and function - if current pressures (tending to promote erosion)
could be removed or reversed.
The initial funding for the research was in the form of a project, "Climate
Change Impacts on UK Upland (peatland) Soils", jointly funded by the
Environment Agency and the NERC research programme Quantifying and
Understanding the Earth System (QUEST). This project was initially led
from the University of Bristol by the QUEST Science and Policy Officer,
Joanna House, supervised by the QUEST Leader, Colin Prentice. Work was
carried out during this initial phase by Angela Gallego-Sala (then a
postdoctoral scientist at Bristol) and Joanna Clark (then a Ph.D. student
at Bangor University). The project's goals were to characterize and model
the distribution of upland peatlands and similar ecosystems nationally and
globally, to assess the consequences of climate change for their
distribution and condition, and to assess (in consultation with national
and regional stakeholders) the implications for policies regarding the use
and conservation of peatland landscapes.
By the start of 2010, both Prentice and Clark had moved to Imperial
College London. The project's publications, and the greater part of its
impact, date from 2010 and onwards. The research formed the subject of a
special issue of the journal Climate Research [1, 2, 3], a paper in Nature
Climate Change [4], and a paper in preparation for Nature Geoscience. The
research contributing to [1, 2, 3] was completed, written up and published
by Clark during her time at Imperial. The global analysis published in
[4], and subsequent research, have been led by Colin Prentice at Imperial.
Research outcomes can be summarized as follows:
i. The area suitable for the initiation of blanket bog in the UK is
projected to shrink, but existing areas of blanket bog could persist is
appropriately conserved.
ii. Statistical models constructed in several different ways can
accurately predict the present distribution of blanket bog in the UK. They
agree on the magnitude and direction of change in the area suitable for
the initiation of blanket bog, i.e. a progressive shrinkage towards a core
area in NW Britain, the degree of shrinkage dependent on the extent of
climate change.
iii. A simple process-based model (based on known requirements of
Sphagnum, the dominant type of moss that composes blanket peat, for cool
summers and year-round wet conditions) makes similar predictions to the
statistical models.
iv. This same process-based model, initially developed for the UK, also
predicts with remarkable accuracy the highly disjunct global distribution
of the blanket bog biome. With climate change, this distribution is
projected to shrink in many regions, although some potential new regions
appear.
The paper in preparation confirms (using palaeoclimate modelling and
palaeoecological evidence) that the distribution of blanket bog in the
British Isles has been closely controlled by climate changes over the past
12,000 years. This is an important finding because there is a residual
belief, based on work published in the 1970s, that blanket peats extended
after about 6,000 years ago because of human deforestation. This can now
be rejected. Policy should not now be based on the assumption that these
peatlands are anthropogenic.
The key researchers contributing to this work at Imperial College were
Professor I. Colin Prentice, Professor of Climate and Biosphere
Interactions at Imperial College from 1 Jan 2010 (now AXA Professor of
Biosphere and Climate Impacts, since 1 Mar 2013) and Dr Joanna M. Clark, a
full time Grantham Institute postdoctoral fellow from Jan 2010. Dr Clark
left Imperial to take up a lectureship at Reading University in Oct 2010.
Publications [1-3] are all from her time at Imperial.
The key external partner and principal funder of the initial project was
the Environment Agency. Other stakeholders who were consulted and attended
meetings included the Countryside Council for Wales, Defra's Soils Policy
Team, Forestry Commission, Macaulay Institute, Moors for the Future,
Natural England, the North Pennine Area of Outstanding Natural Beauty,
Royal Society for the Protection of Birds, United Utilities and the Welsh
Assembly Government.
References to the research
(* References that best indicate quality of underpinning research)
[1] * J.M. Clark, M.F. Billett, M. Coyle, S. Croft, S. Daniels,
C.D. Evans, M. Evans, C. Freeman, A.V. Gallego-Sala, A. Heinemeyer, J.I.
House, D.T. Monteith, D. Nayak, H.G. Orr, I.C. Prentice, R. Rose,
J. Rowson, J.U. Smith, P. Smith, Y.M. Tun, E. Vanguelova, F. Wetterhall
& F. Worrall (2010), `Model inter-comparison between statistical
and dynamic model assessments of the long-term stability of blanket peat
in Great Britain (1940-2099)', Climate Research, 45, 227-248 (2010).
DOI.
[2] * J.M. Clark, A. Gallego-Sala, T. Allott, S. Chapman, T.
Farewell, C. Freeman, J. House, H.G. Orr, I.C. Prentice and P.
Smith, `Assessing the vulnerability of blanket peat to climate
change using an ensemble of statistical bioclimatic envelope models',
Climate Research, 45, 131-150 (2010). DOI.
[3] * A.V. Gallego-Sala, J.M. Clark, J.I. House, H.G. Orr, I.C.
Prentice, P. Smith, T. Farewell and S.J. Chapman, `Bioclimatic
envelope model of climate change impacts on blanket peatland
distribution in Great Britain', Climate Research 45, 151-162 (2010).
DOI.
[4] A. Gallego-Sala & I.C. Prentice, `Blanket peat biome
endangered by climate change', Nature Climate Change, 3, 152-155
(2013). DOI.
Details of the impact
How to conserve and restore peatlands is already a major and
controversial issue for the relevant UK and devolved authorities, while
information about climate change impacts (on top of all the other
pressures) has previously been virtually non-existent.
Before the start of the "Climate Change Impacts on UK Upland
(peatland) Soils" project, many national and local agencies were
aware of the importance of peatlands to the UK carbon balance, water
supplies and biodiversity, and the tangible current threats to the
integrity of peatlands. But there was very little awareness of the
potential for climate change to add to these threats. The project changed
that situation radically (see source [A]). Information about potential
climate change impacts on UK upland peatlands is now well known to the
relevant stakeholders as a direct result of this project. The relevant
transfer of knowledge began via knowledge exchange meetings held in 2009,
and continues today.
The specific benefits of the research include: knowledge of where
peatlands are not threatened by climate change; and knowledge of where
conservation measures are most important to preserve the integrity of
peatlands, both nationally [1, 2, 3] and worldwide [4]. There has been
impact through various public bodies including the following detailed
below.
The peatlands climate change project produced a policy briefing [A],
which covered biodiversity, water, greenhouse gas emissions and land
management aspects. For each of these, it summarised the likely effects of
climate change and recommended actions to mitigate the changes. DEFRA
used this briefing in its UK Climate Change Risk Assessment,
"Climate Change Risk Assessment for the Biodiversity and Ecosystem
Services sector" [B]. This report presents research completed as part of
the "UK Climate Change Risk Assessment (CCRA) for a selected group of
risks in the Biodiversity and Ecosystem Services sector" [B]. Paper
[2] is cited several times and forms the principal evidence base for the
assessment of climate change impacts on blanket bogs.
The IUCN conducted a `Commission of Inquiry on Peatlands'
which was published in Oct 2011 [C, D]. The report represented the "culmination
of 18 months of focused collaboration between peatland experts from land
management, science and policy from across the UK, and revealed the
enormous importance of peatlands for people and wildlife" [D]. The
Inquiry "identified a clear strategy for action to bring peatlands back
from the brink, and point[ed] the way forward to avoid the social and
environmental costs of further deterioration" [D]. The assessment
focused on blanket bog and raised bog peatlands which represent over 95%
of all UK peatland habitat and which offer an opportunity to make early
and substantial progress in delivering a combination of economic, social
and biodiversity gains. The inquiry cited [2], as well as other related
Imperial College publications by Clark (DOIs: 10.1016/j.scitotenv.2010.02.046,
10.3354/cr00923, 10.3354/cr00982),
concluding that the UK needs a policy to conserve peatland carbon stores
[C, D].
In June 2012 an international conference, `Investing in Peatlands -
Demonstrating Success', was held at Bangor University which included a
broad cross-section of academics and stakeholders concerned with peatlands
[E]. The conference was sponsored jointly by the British Ecological
Society and the IUCN's UK Peatland Programme. It coincided with the
release of a report, `Opportunities for UK Business that Value and/or
Protect Nature's Services', which was commissioned for the Ecosystem
Markets Task Force by the Valuing Nature Network and was
financed by Defra and NERC [F]. The report outlined the business case for
valuing and protecting nature's services and highlighted a series of
drivers that are leading businesses to increasingly consider and manage
impacts on ecosystems and to look for business opportunities while they do
so. The report ranked a carbon funding proposal for peatlands as the UK's
top ranked business opportunity from the natural environment [F].
Forest Research, the research agency of the Forestry
Commission published `A Strategic Assessment of the Afforested Peat
Resource in Wales' in October 2012 [G]. The report assessed the
distribution of the Welsh peatlands and provided an overview of the likely
factors impacting peat formation and afforested peat restoration, and
management of the biodiversity, hydrology and greenhouse gas benefits.
Papers [1] and [2] are cited in the report numerous times in relation to
the climate change impacts on peat distribution and the viability of sites
for restoration ([G], sections 4 and 5.2.6).
The work [2, 3] has been cited in a briefing report by the Scottish
Parliament, intended as background to policy making for peatlands
[H]. The following is an excerpt from this Scottish Parliament report (`Box
5 The effect of climate change on Scottish peatlands', p22), where
the references cited are [3] and [2] respectively: "Peatlands are
vulnerable to climate change. As temperatures increase, the areas
suitable for peatlands in Scotland could reduce with the south and east
of their range likely to be under greatest stress [3]. High water
tables in peatlands are maintained by high rates of precipitation and
low evapotranspiration. Peatlands are particularly sensitive to changing
weather patterns for the following reasons:
- Higher temperatures lead to drying out of peat, falling water
table, cracking and erosion
- Increased likelihood of wildfire, leading to significant vegetation
loss
- More heavy rainfall events are likely to cause more erosion on
damaged peatlands However, specific changes to particular peatlands are
very difficult to predict. Climate model predictions apply over large
regions and their implications are often difficult to interpret at small
scales. Warming is expected to have the most significant effect on
peatlands that are already degraded and under pressure - pristine bogs
may be more resilient to small changes in temperature [2]" [H].
The project has generated favourable commentary and further requests for
access to the model outputs by stakeholders including Forest Research, the
James Hutton Institute, the Peatscapes project in the North Pennines and
Scottish Natural Heritage. Some examples (extracted from e-mails to Jo
House) are:
From Judith Stuart, Soils Policy Team, DEFRA:
"I thought the [Climate Research] special issue was very useful. ....
there are so many interesting and relevant papers..... I have been
weaving the information into policy work on peat. So if influencing
policy is a measure of success ..."
From Iain Brown, James Hutton Institute, lead author of the UK
Climate Change Risk Assessment for the biodiversity and ecosystem services
sector:
"Do you think it would be possible for us to use the information,
particularly the headline bioclimate map, in the UK Climate Change Risk
Assessment, appropriately referenced of course? In the Biodiversity
& ESS sector I asked them to look at Blanket Bog as a key habitat
under risk from climate change (we also have changes in soil organic
carbon as another related risk). However the analysis on this currently
in the CCRA is somewhat lacking and I disagree with its findings. Based
upon work we have done previously...your method and findings are much
more robust."
Continuing impacts are expected on two fronts: (a) ongoing policy shifts
at the level of the UK and devolved administrations, recognizing the
implications of climate change for policies concerning upland peatlands:
and (b) increasing global recognition (by IUCN and other bodies) of the
unique nature of the blanket bog biome, the potential restriction in its
area due to climate change, and the importance of identifying and taking
steps to conserve "refugial" areas of this biome.
Sources to corroborate the impact
[A] House, J., Clark, J., ..., Prentice, C., et al., "Vulnerability of
peatland ecosystem services to climate change", Environment Agency
Report SC 070036 (2011). [Can be supplied on request.]
[B] "Climate Change Risk Assessment for the Biodiversity and Ecosystem
Services sector", UK Climate Change Risk Assessment, Defra project code
GA0204 Brown I., Ridder B., Alumbaugh P., Barnett C., Brooks A., Duffy L.,
Webbon C., Nash E., Townend I., Black H. and Hough R., (2012) (available here)
[C] IUCN Commission of Inquiry on Peatlands Final Report, http://www.iucn-uk-peatlandprogramme.org/resources/188
(archived here
on 2/7/13)
[D] IUCN UK Committee, Peatland Programme, `Commission of Inquiry on
Peatlands', Oct 2011 (available here)
[E] Investing in Peatlands - Demonstrating Success, British Ecological
Society,
http://www.britishecologicalsociety.org/blog/2012/06/29/investing-in-peatlands-demonstrating-success/
(archived here
on 3/7/13)
[F] Ecosystem Markets Task Force, Final Report, 14/6/12, http://www.valuing-nature.net/sites/default/files/EMTF-VNN%20study%20final%20report%20140612.pdf
page 53 (archived here)
[G] Forestry Commission document, Oct 2012, http://www.forestry.gov.uk/fr/INFD-8Z7BSH
(archived here)
[H] Scottish Parliament Information Centre (SPICe) briefing, 20/4/12,
http://www.scottish.parliament.uk/ResearchBriefingsAndFactsheets/S4/SB_12-28.pdf
(archived here)
Individual users/beneficiaries who could be contacted by the REF team to
corroborate claims:
[I] Research Fellow, Environment Agency.