Memorandum submitted by the Department
for Environment, Food And Rural Affairs
CLIMATE CHANGE AND WATER SECURITY
1. INTRODUCTION
1.1 The Department for Environment Food
and Rural Affairs (Defra) was set up in June 2001 to drive forward
the Government's aim for sustainable development. This memorandum
outlines how Government policy takes account of the possible implications
of climate change on water issues, such as water resources, flooding,
agriculture and biodiversity.
1.2 The Earth's climate is changing. Global
atmospheric temperatures have risen by about 0.6ºC over the
last century, and the last decade appears to have been the warmest
in the last millennium. The UK's climate has followed the global
trend. Central England temperatures have risen by almost 1ºC
over the last century.
1.3 As global greenhouse gas emissions continue
to increase throughout the 21st century, the Third Assessment
Report of the Intergovernmental Panel on Climate Change (IPCC)
also suggests that global temperatures will rise by between 1.4
to 5.8ºC, and global mean sea levels by 9 to 88 cm, by 2100.
1.4 Defra funded the development of climate
change scenarios for the UK, based on climate modelling carried
out by the Hadley Centre for Climate Prediction and Research (part
of the Met Office). These scenarios (referred to hereafter as
UKCIP02 scenarios) were produced in 2002; they suggest:
— Average annual temperatures across
the UK may rise by between 2ºand 3.5ºC by the 2080s.
— High summer temperatures will become
more frequent and very cold winters will become increasingly rare.
— Winters will also become wetter and
summers may become drier across all of the UK.
— Heavy winter precipitation will become
more frequent, while the amount of snow could decline by 60-90%
by the 2080s.
— Extreme high water levels, which
currently have a 2% annual probability of occurring, could become
10 to 20 times more frequent at some east coast locations by the
2080s.
1.5 Through the UK Climate Impacts Programme
(UKCIP), we are also building a picture of what climate change
means for the UK. Some key impacts relating to water policies
could include:
— Increased flooding risk in many lowland
areas, due to more frequent river flooding and more severe storm
surges.
— Increased occurrence of low flow
and worsening water quality in UK rivers due to lower summer rainfall
coupled with warm temperatures.
— Greater challenges for water supply
due to increased water demand and more frequent droughts.
— Greater climate risks for UK businesses
(including the insurance industry) due to increased weather variability,
with the possibility of transport disruption and damage to buildings;
warmer, drier and sunnier summers could benefit domestic summer
tourism.
2. WHETHER EXISTING
WATER SUPPLIES
ARE ADEQUATE,
AND WHAT
ADDITIONAL SOURCES
OF WATER
MIGHT BE
NEEDED
2.1 The Government's approach to management
of water resources is predicated on the "twin track"
approach of managing demand and developing sustainable resources
where needed.
Management of water resources by the Environment
Agency
2.2 The Environment Agency is the statutory
body with a duty to manage water resources in England and Wales.
The principal mechanism for achieving sustainable management and
development of water resources is through the Agency's system
of abstraction licensing.
2.3 The Environment Agency's Catchment Management
Abstraction Strategies (CAMS) are a mechanism to ensure a sustainable
balance, at the catchment level, between the needs of abstractors
and the environment. CAMS are reviewed and revised every six years.
This allows them to consider the effects of climate change as
further information becomes available. The extension of time-limiting
to more abstraction licences allows the Agency to make adjustments
to ensure that the right balance is struck to both protect the
environment and provide sufficient water for human use.
Environment Agency and water industry forward
planning
2.4 The Environment Agency has national
and regional water resource strategies that set out the pressures
on water resources over the next 25 years and how the Agency will
manage them. Water companies have 25 year water resource plans
which complement the Agency strategies and describe how the companies
aim to achieve a sustainable supply-demand balance for the public
water supply. The plans and strategies will develop over time
as the implications of climate change become clearer and may include
recommendations for development of new resources, such as reservoirs,
as necessary.
Impacts of climate change on the availability
of water resources for the public supply
2.5 The water industry has sponsored work
to link the effects of climate change on water resources. The
Tyndall Centre has developed a procedure[12]
to allow strategic assessments of the effects of climate change
on river flows and groundwater recharge to be made (using UKCIP02
scenarios).
2.6 The 2004 Periodic Review of water prices
is underway. As part of the review, water companies decide how
they will meet their legal obligations to supply water over the
next five years and design schemes to deliver their services in
ways that are acceptable to the environmental and economic regulators.
The Environment Agency has advised water companies to use the
Tyndall Centre research outputs to estimate the effects of climate
change on their water resources in their plans. Ministers expect
water company plans to consider the impact of climate change and
to put forward imaginative and flexible solutions that help to
cope with the full range of climate scenarios that may occur.
Impacts of Climate Change on demand for water
2.7 The Government sponsored the Climate
Change Demand for Water project (CCDeW)[13]
which evaluated the impact of climate change on the demand for
water in England and Wales. It concluded that domestic demand
for water, using medium to high climate change scenarios, would
rise slowly by up to 1.8% in the 2020s and by up to 3.7% by 2050.
Climate change impacts on industry were found to be greater, with
demand rising up to 2.8% in the 2020s and up to 6.1% by 2050.
The study concluded that regional changes in demand brought about
by climate change vary from 1.3% in the North West to 3.9% in
the Anglian region.
2.8 Some water companies have identified
steep rises in household demand, especially those in areas of
housing pressure, as a driver for additional water resource development
in their draft water resource plans. So although the demand for
water affected by climate change is envisaged modestly to increase
nationally in the short term, the combination of regional effects
and large scale housebuilding is expected to have a significant
effect in the south and east of England where water resources
are already under greatest pressure.
Demand management initiatives
2.9 The Government expects demand management
measures to play a full role in achieving a sustainable balance
between supply and demand for water. The scale of new resources
necessary to meet future demand, including that from new housing
development, will be influenced by the extent of advances in water
conservation. Significant gains in leakage reduction have been
made since 1997, and there is now general scope for further improvements.
Further potential for water savings exist in new and existing
buildings, for example through increased metering of households
and use of tariffs to encourage sensible water use, as well as
greater uptake of more water efficient fittings and appliances.
By adopting demand management and water efficiency measures, both
the water industry and its customers are able to moderate the
demand on existing water resources and lessen the need for additional
water resources. Demand management is especially effective at
reducing peaks in demand such as those generated by hotter, drier
summers.
2.10 The Office of the Deputy Prime Minister
(ODPM) has overall responsibility for the planning system. Accordingly,
the ODPM has submitted a separate Memorandum to the Committee
which includes a section on sustainable communities, climate change
and water security. Defra actively participates in ODPM's reviews
of its planning policy guidance.
2.11 Defra is involved in a number of initiatives
to reduce the demand for water. These range from sector-specific
programmes such as Envirowise, to influencing customer behaviour,
to setting minimum standards for water efficiency through regulation.
2.12 The Enhanced Capital Allowance scheme for
water also promotes more sustainable water use by offering tax
relief to businesses investing in certain water efficient technologies[14].
3. WHAT WILL
BE THE
IMPACT ON
RESOURCE MANAGEMENT
(AND PARTICULARLY
THE NEED
FOR CHANGES
IN IRRIGATION
AND WATER
CONSERVATION FOR
AGRICULTURE)
Evaluating the effect of climate change on agriculture
3.1 Over the past 15 years a considerable
amount of research has been funded, through both MAFF and Defra,
on Climate Impacts on Agriculture—including effects on crop
yields. A summary of the research was published in February 2000
entitled: "Climate Change and Agriculture in the United Kingdom."[15]
3.2 Research is continuing and further information
is available on both the Farming and Science pages of the Defra
website.
3.3 Recent studies include:
— An evaluation of regional impacts
of climate change, through an integrated methodology, on the agriculture,
hydrology, biodiversity, and coastal sectors. The project is now
in its second phase and will deliver a software tool for analysing
the impact of potential adaptation strategies.
— An assessment by an independent contractor
to evaluate current understanding of climate change within the
agricultural industry and raise awareness of potential problems
so that the industry can plan for and respond to its effects.
— An assessment of drought risks for
UK crops using UKCIP02 scenarios.
3.4 Overall, research shows that in the
short to medium term, agriculture has the ability to adapt to
a changing climate, although adaptation is more difficult in response
to extreme weather events. The publication, later this year, of
an independent review of Defra's Sustainable Agriculture Unit's
Climate Change Impacts and Adaptations research programme is expected
to inform strategy for commissioning further research and transfer
of information to stakeholders. This will complement initiatives
outlined in the Department's Sustainable Farming and Food Strategy
including ways which are designed to reduce agricultural greenhouse
gas emissions.
Impact of climate change on water resources and
irrigation
3.5 As set out in paragraph 1.5, the effect
of climate change in the long term is likely to place more stress
on water resources.
3.6 According to the CCDeW study, climate
change could affect irrigation water use via changes in plant
physiology, altered soil water balances, cropping mixes, cropping
patterns, and change in demand for different foods. The study
indicates that by the 2020s, central England will experience conditions
similar to those currently typical of eastern England, and by
the 2050s eastern, southern and central England will have irrigation
needs higher than those currently experienced anywhere in England.
Demand options to reduce the environmental impact
of agriculture on water resources
3.7 With increasing pressures on water resources
in the future it is important that more sustainable water use
patterns are adopted. Peak demands for irrigation coincide with
the season when there is least water available for abstraction
and are likely to have detrimental impacts on the water environment,
habitats, etc. These impacts can be mitigated by, for example,
employing more water efficient irrigation systems or utilising
alternative sources of water.
3.8 There is significant scope for improving
water conservation in agriculture through the use of more efficient
technologies and good management practices, such as monitoring
and managing water use, good maintenance of equipment and identifying
and repairing leaks. In water stressed regions in the UK, installation
of a winter storage reservoir can ease the need to abstract water
from existing sources for irrigation during the critical summer
months. For certain regions of England, Defra may be able to provide
funding under the Rural Enterprise Scheme[16]
towards the construction of winter storage reservoirs. The Enhanced
Capital Allowance scheme will also have some applicability.
4. THE IMPLICATIONS
FOR FLOOD
MANAGEMENT, INVESTMENT
IN MITIGATION
MEASURES, AND
FOR WIDER
POLICY SUCH
AS PLANNING
4.1 It has been recognised for many years
that climate change will have a significant impact on flooding
and coastal erosion. The primary drivers of changes in flood and
erosion risk will be changes in normal and extreme sea levels
and coastal storms; changes in precipitation and temperature will
also affect river flooding, other natural and man-made drainage
systems and coastal land stability.
4.2 There may be some regional differences,
with the south and east coasts more vulnerable to sea level change
(due to long term land movements) and the north and west possibly
more vulnerable to increased precipitation, though there is great
uncertainty attached to these forecasts. A precautionary approach
to the potential impact on flood and coastal erosion management
is taken into account in current guidance for strategic planning
and scheme appraisal and funding. This guidance is kept under
review as further research findings emerge.
4.3 The Foresight study of flood and coastal
defence (DTI 2004[17])
has suggested that with maintenance of current flood and coastal
erosion management infrastructure, the total risk in economic
terms could increase 2 to 20 fold, across a broad range of future
climate and socio-economic scenarios. This is largely due to the
increased frequency of extreme events and the increases in development
and wealth in risk areas. The changes in economic risk would be
reflected in changes in exposure for people and the natural environment.
Key issues for control of this risk in the future are the way
in which flood management infrastructure is maintained and developed
recognising that the areas most at risk in the future are those
that already depend on defences today.
4.4 It is recognised that future defence
management will involve some difficult decisions and that it will
not be physically possible, or desirable, to maintain all current
defences. A rational basis for decision making is encouraged through
strategic approaches which balance natural processes, the needs
of present and future generations and pressures on the natural
environment. Current guidance for all new Shoreline Management
Plans and Catchment Flood Management Plans is that they should
take specific account of potential climate change over the next
50 to 100 years.
4.5 The potential for increased frequency
of intense rainfall events could put particular pressures on urban
drainage systems. This may result in more surface water drainage
problems and sewer flooding events. Changes in rainfall patterns
may also affect the frequency of groundwater emergence, which
can also lead to flooding. There may be a need for integrated,
longer-term planning of both urban drainage and groundwater with
wider river and coastal flood risks which takes the potential
impacts of climate change into account.
4.6 Defra is currently leading work to update
the 1993 Strategy for Flood and Coastal Defence with a new Strategy
for Flood and Coastal Erosion Risk Management. This aims to fully
embed sustainable development in flood and coastal erosion risk
management policy in the context of future drivers, including
climate change.
Flood and Development Planning Issues
4.7 Other policy areas, such as development
planning will also have a significant role in flood management.
As described in paragraph 2.10, the ODPM Memorandum to the Committee
also includes a section on the relationship between planning,
flood management and climate change. The current planning guidance
on flood management—PPG25 Development and Flood Risk—will
be reviewed later this year. Defra will take an active part in
that review.
5. WAYS IN
WHICH THE
IMPACT OF
CHANGES IN
WATER AVAILABILITY
ON BIODIVERSITY
CAN BE
MINIMISED
Effects of climate change on biodiversity
5.1 Research studies have shown that climate
change is likely to have a major impact upon biodiversity in England.
Some species will be affected directly as climatic conditions
within their current distributions become less suitable. This
may lead to the local extinction of vulnerable species. Some habitats
and their associated species will be affected by changes to the
hydrological cycle, especially increases in summer drought in
south east England. Coastal habitats will tend to migrate landward,
or be lost as a result of being "squeezed" against hard
coastal defences, through rising sea levels and increased storm
frequency and intensity. An increase in the frequency and intensity
of flooding may also have an adverse effect on biodiversity on
fresh water sites.
5.2 Climate change will also have indirect
effects on biodiversity through, for example, changes in land
use, demand for water, and patterns of recreational activity.
In addition, conditions may become more favourable for the spread
of invasive non-native species. Such indirect effects need not
necessarily all be negative. For example, floodplain and coastal
management can provide opportunities to restore and re-create
wetland habitats. Actions to reduce carbon dioxide emissions by
improving carbon storage in vegetation and soils, can also provide
opportunities to enhance wetland ecosystems such as peatlands.
Action against damaging water abstraction
5.3 The Environment Agency is engaged in
its Restoring Sustainable Abstraction programme, which examines
the impacts of licensed abstractions on the environment. This
will lead the Agency to take action against damaging abstractions,
where necessary, in order to protect the flora and fauna dependent
upon rivers and wetlands. Action taken now to achieve sustainable
abstraction will lay the groundwork against future pressures resulting
from climate change.
Minimising effects of climate change on biodiversity
5.4 There is much uncertainty about future
climates so our response has to be to maximise the adaptive capacity
of the predominantly semi-natural ecosystems in England and to
avoid setting ourselves impossible tasks in trying to maintain
current or restore pre-existing patterns of biodiversity. The
UK has called for greater recognition of the mobility of species
and habitats as a consequence of climate change and for this to
be taken into account in amendments to the EC Habitats Directive.
5.5 All our objectives for 20 or 50 years
hence should take account of the likelihood of significant climate
change. In helping biodiversity to flourish now, we are also improving
its ability to cope with future pressures. In promoting policies
which regard biodiversity as a component of a larger ecosystem,
operating across whole landscapes or seas, we are better able
to manage change in those ecosystems to sustain biodiversity.
5.6 As our knowledge of the likely impacts
of climate change improves, through continued research and monitoring,
we will need to adjust our management strategies and target actions
where they will be most effective in enabling vulnerable species
to survive or to disperse to and colonise new areas whilst maximising
the benefits for biodiversity of other adaptation and mitigation
measures.
5.7 The UK Biodiversity Action Plan (BAP)
and the England Biodiversity Strategy provide the necessary policy
framework to adapt to the long-term implications of climate change.
It will be an important factor in the continuing management of
priority species and habitats and in the planning of actions to
conserve them. The BAP and the Strategy also provide systematic
frameworks of reporting and monitoring, which can be used to steer
adaptation to climate change over the coming decades; indicators
published as part of Measuring Progress: baseline assessment[18]
include: Changes in abundance of climate sensitive species at
Environmental Change Network sites in England.
6. CONCLUSIONS
— Climate change is expected to have
an impact on water resources, flooding, on agricultural demand
for water and biodiversity over the longer term in England.
— The Environment Agency will continue
to manage water resources and ensure that climate change implications
are built into water resource forward planning that encapsulates
the twin track approach.
— In the future the Environment Agency
will use CAMs to re-allocate water resources, and its powers to
take action against damaging abstraction where necessary.
— Demand management measures need to
play a full role in achieving a sustainable balance between supply
and demand for water.
— A review of Sustainable Agriculture
Unit's "Climate Change Impacts and Adaptations Research Programme"
will be published later this year, to inform the agricultural
research strategy.
— Defra is currently leading work to
update the 1993 Strategy for Flood and Coastal Defence with a
new Strategy for Flood and Coastal Erosion Risk Management.
— The UK Biodiversity Action Plan and
the England Biodiversity Strategy provide a policy framework to
adapt to the long-term implications of climate change.
Department for Environment, Food and Rural Affairs
April 2004
12 "Effect of Climate Change on River Flows
and Groundwater Recharge: UKCIP02 Scenarios" for UK Water
Industry Research Ltd (2002). Back
13
"CCDeW: Climate Change and Demand for Water"
February 2003, available from www.defra.gov.uk Back
14
Enhanced Capital Allowances are available on products listed
on the Water Technology List, for businesses that pay Corporation
Tax. Back
15
Available from the Defra website, www.defra.gov.uk Back
16
The Rural Enterprise Scheme (RES) is one of ten schemes which
form part of the England Rural Development Programme. The scheme
provides targeted assistance to projects that support the development
of more sustainable, diversified and enterprising rural economies
and communities. Back
17
Office of Science and Technology (2004), Foresight Flood and
Coastal Defence Project: Future Flooding Executive Summary
found at: www.foresight.gov.uk. Back
18
Available from www.defra.gov.uk/wildlife-countryside/ewd/biostrat/index.htm Back
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