Select Committee on Environment, Food and Rural Affairs Written Evidence


Memorandum submitted by the Natural Environment Research Council (NERC)

CLIMATE CHANGE AND WATER SECURITY

  The Natural Environment Research Council (NERC) welcomes the opportunity to provide input.

  NERC is one of the UK's seven Research Councils. It funds and carries out impartial scientific research in the sciences of the environment. NERC trains the next generation of independent environmental scientists. Its priority research areas are: Earth's life-support systems, climate change, and sustainable economies.

  NERC's research centres are: the British Antarctic Survey (BAS), the British Geological Survey (BGS), the Centre for Ecology and Hydrology (CEH) and the Proudman Oceanographic Laboratory (POL). A list of NERC's collaborative centres is appended (Annex 4).

  For this inquiry, NERC is submitting evidence from BGS (Annex 1), CEH (Annex 2) and the Tyndall Centre for Climate Change Research (Annex 3), together with a summary of the main points and an introduction to relevant NERC programmes compiled by Swindon-Office staff.

INTRODUCTION

  NERC currently supports a number of programmes relevant to the issue of climate change and water security. Of most direct relevance is the LOCAR (Lowland Catchment Research) thematic programme, and it's companion project, CHASM (Catchment Hydrology and Sustainable Management). The major objective of both LOCAR and CHASM is to produce integrated hydro-environmental research on the input-storage-discharge cycle of in-stream, riparian and wetland habitats within groundwater-dominated systems.

  Also of relevance are: COAPEC (Coupled Ocean-Atmosphere Processes and European Climate), RAPID (Rapid Climate Change) and RELU (Rural Economy and Land Use). The goal of COAPEC is to determine the impact on climate, especially European climate, of the coupling between the Atlantic Ocean and the atmosphere. The major objective of RAPID is to improve our ability to quantify the probability and magnitude of future rapid change in climate, with a main (but not exclusive) focus on the role of the Atlantic Ocean's thermohaline circulation; major changes in this circulation obviously have significant implications for climate (and hence water availability) in Europe. The RELU programme focuses on understanding the social, economic, environmental and technological challenges faced by rural areas, including the issues of water quality and sustainability.

SUMMARY

  Much of the research into probable climate-change effects on water availability and flooding involves using scenario approaches (eg UK Climate Impacts Programme (UKCIP) scenarios) based on Global Climate Models (GCMs) and regional climate models. There is necessarily a limit to the number of scenarios which can be run, and to the number of factors which can be considered. The uncertainties involved make it difficult to make accurate predictions, although progress is being made in taking account of them. The following effects of climate change on water security appear probable.

  1.  Changes in seasonal rainfall and temperature are likely, with winters becoming wetter and summers drier and hotter. There will be a greater likelihood of weather extremes, and greater variability between years. Water-management systems will need to be flexible to cope with this.

  2.  The effects of climate change are likely to vary geographically; for example, temperatures are likely to increase more in the southeast than in the northwest of England.

  3.  Hotter and drier summers will lead to more demand for water, particularly for agricultural purposes and for potable water supply. Irrigation of all but the highest-value crops could be at risk, and the cultivation of some may have to migrate to higher-rainfall areas of the country.

  4.  Seasonal increases in demand for water will have to be met by increased use of reservoir and groundwater, in part to maintain good ecological status and amenity value of rivers. The effect of climate change on water supply reliability will depend to a large extent on how individual catchments are managed, in particular to cope with competing demands.

  5.  In the agricultural sphere, measures such as increased support for the construction of on-farm small-scale reservoirs and the use of trickle irrigation should be considered, and there is scope for developing rainfall-harvesting and "dirty"-water recycling technology.

  6.  Groundwater will be particularly important because of the size of the reserves and because it is less directly affected than surface water by the climate itself; however, there is concern that the quality of groundwater may suffer, and measures may also be required to enhance groundwater recharge, ie by artificial and induced recharge, especially if an increase in the frequency of extreme rainfall events alters the balance between runoff and natural recharge.

  7.  Flooding, especially groundwater flooding, is likely to become more common, partly because of an increase in the frequency of extreme rainfall events, partly because of the urbanisation of water meadows and similar areas. Our ability to make predictions in this area would benefit from the inclusion in models of changes in land use alongside changes in climate. Of three broad approaches to managing flood risk (reducing the physical hazard, reducing exposure to flood loss, and reducing vulnerability), reducing exposure to flood loss is likely to be the most resilient in the face of climate change.

  8.  Climate change affects in-stream and riverine ecosystems primarily through changes in river-flow regimes and water temperature. It may be possible to maintain current flow regimes and hence ecosystems, although if this becomes unsustainable, alternative approaches may have to be considered.

Natural Environment Research Council (NERC)

April 2004



 
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