Department of Energy
& Climate Change
3 Whitehall Place,
London SW1A 2HD
www.decc.gov.uk
Mr John Simpson
3 June 2009
[email address]
Our ref 09/0610
Dear Mr Simpson
Provision of requested information
Thank you for your request for information about future projections of UK and global
temperatures, which we received on 5 May. Your request has been considered under the
Environmental Information Regulations (EIR) 2004 because the information requested relates
directly to future changes of the state of the elements of the environment as defined by EIR
Regulation 2(a).
With respect to your request for future UK temperatures, following the creation of the
Department of Energy and Climate Change (DECC) in October 2008, policy responsibility for
projected UK temperatures remains with the Department for Environment Food & Rural Affairs
(Defra), who you will need to approach to obtain this information. They can be contacted via
their helpline 08459 33 55 77 or by e-mailing them at
[email address] and specify that
your request should be directed to the Adapting to Climate Change Unit (ACC) in Nobel House.
Regarding projections of future global temperatures, much of this information is already in the
public domain. In the first instance, the basic information can be obtained by consulting the
2007 Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change
(IPCC). In particular, chapter 10 of the Working Group 1 contribution to the AR4 gives
information relating mainly to unmitigated global greenhouse gas emissions scenarios (such as
‘business as usual’), but it also has some information on the effects of mitigation policies i.e. the
projected global temperature response to global emissions reductions. Chapter 3 of the Working
Group 3 contribution to the AR4 gives more detail on the projected effects on global
temperature, for a range of different levels of greenhouse gas emissions reductions. These
reports are available online at the IPCC’s websit
e www.ipcc.ch .
However, the IPCC report only reviewed scientific research published up to mid 2006 and there
has been some further work on future global temperatures since publication of that report.
Accordingly, we refer you to two studies published recently in the journal Nature; the main
study1 discusses the amount of greenhouse gases that can be emitted between now and 2050
to give a reasonable chance of restricting future global warming to 2°C over pre-industrial. The
1 Meinshausen, M, et al, April 2009, ‘Greenhouse gas emission targets for limiting global
warming to 2°C’, Nature, doi: 10.1038/nature08017
companion study2, undertaken mainly by UK scientists, also considers the effects of cumulative
carbon emissions on global warming.
For your information we also attach an unpublished powerpoint presentation that DECC holds
entitled ‘Mitigation scenarios developed to inform Defra at COP13’ which was originally
prepared by two scientists from the Met Office Hadley Centre to inform the UK’s contribution to
the international climate negotiations that was held in Bali, Indonesia, in December 2007. The
version attached is the one that was improved and updated in October 2008. This work provides
assessments of the probability of exceeding future warming levels of 2°C and 3°C above pre-
industrial for various greenhouse gas emissions projections.
You may be interested to know that DECC, in collaboration with Defra, is funding a major four
year project (called AVOID) which includes further work on emissions trajectories that aim to
limit future global temperature rises to a level that gives the best chance of avoiding dangerous
climate change. One of the results of this project will be an improved assessment, compared to
the attached powerpoint presentation, of the probabilities of exceeding specified future global
temperature targets and is scheduled for completion in May 2012. However, following the
project’s completion in December 2012 all the results of this project will be published on
DECC’s public website as well as in hard copy form. As this is material still being worked on (or
not yet started) with the aim of publication on completion we are entitled under EIR regulation
12.(4)(d) to temporarily withhold any interim information that we may hold.
You asked how accurate we consider these future temperature projections to be; as they are
entirely the result of climate model simulations of future climate, these global temperature
projections are inevitably subject to a degree of uncertainty and cannot be assessed for
accuracy. However, scientists are confident that climate models do give credible projections of
future climate change for the following reasons 1) they are based on fundamental physical
principles, 2) they correctly reproduce the main features of the currently observed climate, 3)
they correctly reproduce the 20th century global temperature history and 4) they have been
successfully tested on past climates such as the one that prevailed at the last glacial maximum
when conditions were very different from those at present. Also, modelling techniques enable
probability assessments to be made for future temperature projections, which indicate the
likelihood of their occurrence.
Finally, in response to your question on whether the department uses a specific forecast of
temperature increases to help form policy, the department has to consider the full range of
temperature projections and their implications, in line with the IPCC’s recommendation that all
future emissions scenarios should be considered equally likely, i.e. not weighted. However, we
would point out that the Government’s recent decision to aim for a greenhouse gas emissions
reduction target of 80% below a 1990 baseline by 2050 was taken on the advice of the
Committee on Climate Change (CCC)3, who in their analysis considered emissions trajectories
that would result in the highest probability of limiting future warming to around 2°C over pre-
industrial. The CCC’s report is publicly available and can be read on the CCC’s website at
http://www.theccc.org.uk/ .
The information supplied to you continues to be protected by the Copyright, Designs and
Patents Act 1988. You are free to use it for your own purposes, including any non-commercial
research you are doing and for the purposes of news reporting. Any other re-use, for example
commercial publication, would require the permission of the copyright holder. Most documents
supplied by DECC will have been produced by government officials and will be Crown
2 Allen, M.R., et al, 2009, ‘Warming caused by cumulative carbon emissions towards the
trillionth tonne’, Nature, doi: 10: 1038/nature08019.
3 The CCC is an independent body established by the Government under the terms of the
Climate Change Act to advise on carbon reduction targets and to monitor progress towards
achieving them.
Copyright. You can find details on the arrangements for re-using Crown copyright on OPSI
(Office of Public Sector Information) at:
http://www.opsi.gov.uk/click-use/index.htm
Information you receive which is not subject to Crown Copyright continues to be protected by
the copyright of the person, or organisation, from which the information originated. You must
ensure that you gain their permission before reproducing any third party (non Crown Copyright)
information.
In keeping with the spirit and effect of the Environmental Information Regulations 2004, all
information is assumed to be releasable to the public unless exempt. The information you
requested may now be published on our website together with any related information that will
provide a key to its wider context.
If you have any queries about this letter, please contact me. I also attach an annex giving
contact details should you be unhappy with the services you have received.
Yours sincerely
Paul Munro
Climate and Energy: Science and Analysis
Email [email address]
Annex
Complaints
If you are unhappy with the service you have received in relation to your request you may make
a complaint or appeal against our decision within 40 working days of the date of this letter.
Please write to the responding officer who wil then arrange with BERR’s Information Rights Unit
an internal review of your case.
If you are not content with the outcome of the internal review, you have the right to apply directly
to the Information Commissioner for a decision. Please note that generally the Information
Commissioner cannot make a decision unless you have first exhausted BERR’s own complaints
procedure. Contact details for The Information Commissioner are on their website at
http://www.ico.gov.uk/ .
