Select Committee on Environment, Food and Rural Affairs Written Evidence


Memorandum submitted by English Nature

CLIMATE CHANGE AND WATER SECURITY

KEY ISSUES AND SUMMARY

Implications of climate change

  1.  During the 21st century winters are likely to become wetter and summers drier, continuing the present trend. These effects will be most marked in south and east England. Sea-level rise is also due to continue.

  2.  In terms of available water resources, as these are already tight in the south-east, greater emphasis will need to be placed on winter storage and on the efficient use of water.

  3.  Flood management will need to adapt to storm events by adopting a catchment-wide approach, involving reduction of run-off and using the natural storage capacity of floodplains. At the coast, many of the current defences are unsustainable, and a strategic programme of managed realignment should be promoted.

  4.  Government should seek to create a better public understanding of the need to adapt to climate change: this could help make consumers more aware of the true costs of meeting their demands for water and lead to a more flood-tolerant society.

Implications for biodiversity

  5.  Wetlands are already under pressure due to water abstraction, particularly from ground water in the summer months. Action must be taken forward during the AMP4 period to tackle known problems due to water company abstraction. The changes in the licensing system under the Water Act and the introduction of Catchment Abstraction Management Strategies have the potential to reduce damaging abstractions, provided this is not overridden by the duty on the Environment Agency under the Water Resources Act to meet the needs of water companies. Full recovery of wildlife habitats may in some cases require restoration work, which should be funded from licence charges.

  6.  Increasing demand, particularly in the south-east, makes it crucial that winter storage, metering and water-efficient housing become the norm if wildlife habitats are not to suffer further. Such measures will not, however, prevent some of the major changes to wildlife habitats predicted under climate change scenarios. Approaches must be developed, particularly through the planning process, which enable vulnerable and important nature conservation sites to adapt to climate change and minimise losses to biodiversity.

  7.  The current situation in relation to flood and coastal defence is particularly serious—a large proportion of wildlife sites across England is adversely affected by drainage. However, adoption of a catchment approach, involving land-use change and increased floodplain storage, could produce a "win-win" situation for flood risk management and nature conservation. Similarly, managed realignment at the coast will benefit salt-marsh and other intertidal wildlife habitat, although future planning will need to ensure provision of habitat to compensate for consequent losses to freshwater habitats. Both of these will require a change in the cost-benefit system, which currently favours hard defences installed at the point of flooding/erosion.

1.  INTRODUCTION

  English Nature is the statutory body that champions the conservation and enhancement of the wildlife and geological features of England. We work for wildlife in partnership with others, by:

    —  advising—Government, other agencies, local authorities, interest groups, business, communities, individuals on nature conservation in England;

    —  regulating—activities affecting the special nature conservation sites in England;

    —  enabling—others to manage land for nature conservation, through grants, projects and information;

    —  enthusing—and advocating nature conservation for all and biodiversity as a key test of sustainable development.

  We have statutory responsibilities for nationally important nature conservation sites: Sites of Special Scientific Interest (SSSIs), the most important of which are managed as National Nature Reserves.

  Through the Joint Nature Conservation Committee, English Nature works with sister organisations in Scotland, Wales and Northern Ireland to advise Government on UK and international nature conservation issues.

2.  CLIMATE CHANGE EFFECTS ON PRECIPITATION

  2.1  The UK Climate Impacts Programme (UKCIP02) projects considerable changes in precipitation over the UK during the 21st Century. Winters are likely to become wetter and summers drier, continuing the trend observed in the last century. The frequency and intensity of winter precipitation will continue to show a marked increase, and very dry summers might occur in 30% of years by the 2050s.

  2.2  The largest changes in precipitation are likely to be experienced in eastern and southern England, and the smallest in the north-west of Scotland. Depending upon levels of greenhouse gas emissions, winter increases in precipitation could range from between 10-15% and 15-35%, and summer decreases from up to 35% to 50% or more. Soil moisture would decrease across the whole of the UK, with reductions of 20% to 40% being experienced in south-east England. Snowfall is likely to decrease by up to 90% or more in coastal areas and in the English lowlands, and 60% or more in the Scottish Highlands.

3.  EXISTING CONCERNS—ARE WATER SUPPLIES ADEQUATE?

  3.1  The balance between water supply and demand—for industry, irrigation and households—varies across England, but in some areas water supplies are already insufficient. For example, the Environment Agency reports that in its Southern Region, the total quantity licensed for abstraction from rivers and streams already exceeds that which would be available in a drier-than-average summer. Corresponding considerations for a dry winter suggest that parts of Kent and East Sussex are potentially over-licensed. The Region's groundwater resources are already over-licensed in relation to a dry year and future demand in the Region will continue to grow, with plans for economic growth as well as demand for further housing. Government planners suggest that provision will need to be made for some 380,000 additional houses in the region by 2016[12].

4.  IMPACTS OF CLIMATE CHANGE ON BIODIVERSITY

  4.1  English Nature and the Environmental Change Institute (University of Oxford) are leading a major research project (the MONARCH project: Modelling Natural Resource Responses to Climate Change) into the potential impacts of climate change on nature conservation in Britain and Ireland. The project is funded by a consortium of 15 governmental organisations and NGOs.

  4.2  Computer simulation models are used to predict the possible impacts of climate change on plant and animal species, their habitats and on the functioning of the ecological systems with which they are associated. The results are being used to assess current nature conservation policy and management practice, and to formulate adaptation measures to accommodate change, both in protected areas and in the wider landscape, and in association with other key sectors which influence land and water use. The model predictions for water requirements in two habitat types are illustrated below:

Example 1: Wet heath

  The MONARCH study[13] predicts changing distributions of wet heath over the next 50 years. The distribution of this habitat type may expand in Ireland and some northern and western areas of Britain, where increased winter rainfall may tend to saturate formerly dry heath. However, in south-east England, low rainfall and increased rates of evapotranspiration in summer may reduce water availability in many wet heaths, which could revert to dry heath or be replaced by acid grassland. Recent more detailed work in the New Forest supports this prediction and suggests that wet heath may become progressively restricted following falling water tables. The characteristic wet heathland plant, cross-leaved heath, best adapted to wet conditions and currently found throughout Britain, may give way to more drought-tolerant species, such as bell heather.

Example 2: Beech woodlands

  The natural distribution of beech is confined to the south of England (the historical limit of its spread during the Holocene), although it has been planted extensively and thrives elsewhere. Beech is a drought-sensitive species which, in parts of its natural range, is likely to decline as soils become drier in summer. Results from the MONARCH study suggest that, by the 2050s, such areas may not support beech woodlands in their current form, as more drought-tolerant species increase their competitive ability. Oak could spread into habitat vacated by beech, and yew could expand its range. Again, this prediction is supported by recent work in Hampshire, where beech woodland could be negatively affected by soil-moisture stress and invasion of competitive species. The natural range of the beech is likely to shift northwards with climate change, but this will only be realised if appropriate "managed" opportunities are put in place to aid dispersal.

  4.3  The first phase of the MONARCH project had as its primary focus terrestrial systems, and this is underpinning subsequent phases of the study. Complementary programmes for coastal and marine environments have been established by other research consortia: a new project dealing with climate change impacts on freshwater ecosystems is due to start this year. Led by the Environment Agency, this work will consider standing water bodies, lowland rivers, upland headwater streams and managed water courses, together with other wetland habitats not covered in MONARCH.

5.  IMPACTS OF ABSTRACTION

  5.1  Drainage and water abstraction are drying out many of the wetland habitats of lowland England. Abstraction from groundwater is an important cause of unfavourable condition for standing open water SSSIs (especially aquifer-fed lakes) and for river and stream SSSIs (particularly chalk rivers). Some fen types and other spring-fed wetland habitats are very sensitive to abstraction and recharge of groundwater aquifers. Restoration of lowland raised bogs, degraded through habitat loss and drainage, may require the reduction or prevention of groundwater abstraction. Populations of breeding waders have declined in England's lowland wet meadows due to the long-term effects of land drainage and water abstraction[14].

  5.2  In response to existing pressures from over-abstraction by water companies, about £60 million is being spent under AMP3 on water resources schemes affecting 18 SSSIs, with investigations taking place at a further 27 SSSIs. Under AMP4 (2005-10), schemes to tackle water resources problems are needed at 46 sites and investigations are required at a further 61.

6.  BIODIVERSITY AND FLOOD DEFENCE—LAND-USE APPROACH

  6.1  The increased frequency of flooding in recent years is due not only to more severe rainfall events, but also to changes in land-use which lead to more rapid run-off from catchments. These changes include: large-scale moor gripping of upland bogs; underdrainage of agricultural fields; canalisation of streams to convey rainwater more quickly to rivers; afforestation and clear-felling; ploughing of grassland for crop production, causing topsoil to be washed into streams and rivers and reducing their channel capacity; intensive stocking of sheep; building of roads and other developments with hard surfaces which act as pathways for run off. Many of these changes have also led to increased diffuse pollution. All of them have negative impacts on biodiversity and such effects will be exacerbated by more severe winter rainfall and summer drought events driven by climate change.

  6.2  Climate change models have predicted an increase of up to 20% in river peak flows, and hence flooding risk, over the next 50 years. This places even greater importance on the need to ensure sustainable approaches to flood management through a catchment wide approach, maximising habitat recreation opportunities as well as reducing the need for further hard engineering solutions to protect urban areas.

  6.3  A catchment-wide approach to flood management means starting in the upland headwaters and securing land-use changes which will lead to less rapid run-off. In the lower catchment, greater use can be made of natural floodplain storage. The potential for multiple benefits from such measures needs to be realised. However, there is not an integrated funding source which would enable these more sustainable approaches to begin to replace the conventional engineered defences. In 2004, Defra—working with English Nature and the Environment Agency, and drawing in the RDS (agri-environment schemes), Forestry Commission, the local council and others—has initiated a pilot project on the catchment upstream of Ripon. This aims to test how land-use changes can be incorporated with a flood-defence scheme.

7.  IMPACTS OF SEA-LEVEL RISE

  7.1  Sea-levels are rising in the southern half of Britain due to natural geological processes. In areas where this is most pronounced (southern and eastern England), this results in "coastal squeeze" where intertidal habitats, trapped between rising sea-levels and fixed seawalls are eroded away. This process has implications for both flood management (increasing cost of seawall maintenance and the need to abandon some uneconomic defences, exacerbated also by the impact of increased storminess), as well as nature conservation (loss of intertidal habitats and of freshwater sites that are currently protected by seawalls). As a result of climate change, it is anticipated that "coastal squeeze" will accelerate, especially in southern and eastern England where sea level rise is likely to be greatest.

  7.2  Sea walls, erected to reclaim land from the sea, have constrained the ability of intertidal habitats, especially saltmarsh, to migrate over the coastal floodplain in response to relative sea-level rise. In the 25 years between 1973 and 1998 in what is now the Essex Estuaries Special Area of Conservation (cSAC), a quarter of the saltmarsh was lost to erosion. In the Blackwater Estuary alone, 142 hectares of saltmarsh were lost between 1973 and 1988, with a further 55 hectares in the following 10 years. The rate of sea-level rise on the Essex coast is predicted to rise to 6 millimetres a year over the next 50 years, and further significant losses of saltmarsh are predicted.

  7.3  Managed realignment, as has occurred at Tollesbury, Essex and Paull Holme, on the Humber, can effectively create new intertidal habitats and allow replacement of losses of saltmarsh, as well as delivering technically and economically sound and sustainable flood defences. However, the number of managed realignment schemes is currently inadequate to address existing ongoing losses.

  7.4  One key element of this approach is the need to re-create freshwater wetlands that cannot be conserved in situ, in sustainable locations inland. At least 29,000 hectares of internationally important floodplain wetlands (Special Protection Areas for birds (SPAs), Ramsar sites and cSACs) are currently protected by seawalls in south-east England and so are potentially vulnerable to the effects of sea-level rise exacerbated by climate change[15]. A long-term strategic programme is needed to recreate wetlands further inland on floodplains to compensate for these losses. Although there are some local initiatives by English Nature, the Environment Agency, Wildlife Trusts, RSPB and others (Great Fen Project in Cambridgeshire, Severn and Avon Vales Wetland Partnership, Gainsborough Washlands), the means for recreating wetlands at the coast and inland need to be incorporated in flood-risk planning and funding and in agri-environment schemes. If this is to be delivered in a strategic way there is a need to identify suitable locations and to ensure that there is an adequate water supply to enable and sustain good quality habitat creation. Further research is needed in this area.

  7.5  Rising sea-levels will also result in increased saline intrusion into aquifers, with implications for both water supply and nature conservation. Locations where this is a concern include Dungeness, Kent and Pevensey Levels, East Sussex. In both instances these sites are important abstraction points for freshwater supply and are of nature conservation interest. One of the outcomes of such saline intrusion inland will be a gradual evolution of the type of nature conservation interest that is present to one that is less characteristic of freshwater.

8.  MANAGING AND ADAPTING TO CLIMATE CHANGE FOR BIODIVERSITY

  8.1  Evidence suggests that we are currently committed to at least 50 years of rapid climate changes (and an average warming of 1.5ºC in that time). In the longer-term, the amount of climate change will be determined by decisions made now about the management of the world's greenhouse gas emissions. However, due to the lengthy activity times of greenhouse gases once in the atmosphere, the effects of measures to halt and reverse such trends are unlikely to be realised until well into the second half of this century. Over the short to medium term, adaptation measures are essential if we are to maintain levels of biodiversity in the face of inevitable impacts of climate change.

  8.2  Future water resources planning strategies will need to consider measures which will mitigate the effects of climate change on water resource demand. Such measures should include the promotion of more sustainable use of water, through household metering and more efficient use of water by industry (including agriculture), as well as educating and encouraging consumers on the measures they can take as individuals (see for example advisory literature produced by Thames Water[16]).

  8.3  Provision of alternative sources will be important. More flexible arrangements are needed to manage and exploit different sources of water within different regions. Water companies will need to work with Government to switch resources from primarily groundwater in summer to surface water in winter (especially in the south east of England), and emphasis should be placed on the need to plan for water storage areas to enable exploitation of heavier, more episodic winter rainfall, and aquifer recharge. More sustainable solutions are needed to achieving and maintaining the quality of water supplies by taking action to control diffuse pollution at source.

  8.4  Adaptation to climate change will require changes in the long-term planning for nature conservation. In addition to improvements in our ability to predict where habitats and species are likely to be lost, measures will be needed which facilitate dispersal and colonisation as areas change in their suitability for different habitats and species, link fragmented habitats, and ensure that new locations for colonisation are available. The rationale and actions needed to build adaptation into nature conservation policy, planning and management is set out in Climate change and nature: adapting for the future, an information paper published by English Nature, IUCN-The World Conservation Union, RSPB and WWF[17].

  8.5  Under the Water Framework Directive, River Basin Management Plans are due to be introduced by 2009. They present a long-awaited opportunity for integrated catchment management. Although the Directive focuses on water quality and does not cover all of flood management, water resource management or vulnerable wetlands, English Nature has proposed to Government that steps should be taken to integrate all aspects of managing the water environment in one Plan (rather than having a set of parallel plans).

English Nature

April 2004



12   Environment Agency (2001) Water Resources for the Future-a summary of the strategy for the Southern RegionBack

13   The MONARCH study: (www.ukcip.org.uk/model_nat_res/model_nat_res.html) Back

14   English Nature (2004) State of Nature: Lowlands-future landscapes for wildlifeBack

15   English Nature (2003) Living with the sea: managing Natura 2000 sites on dynamic coastlinesBack

16   Thames Water (2003) Saving Money by Saving WaterBack

17   Climate change and nature: adapting for the future: www.iucn.org/themes/climate/docs/climateandnature.pdf. Back


 
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