Climate change impacts on the water cycle, resources and quality

Research Needs

Most water and flood risk planning horizons end before the 2050s, the point at which climate-driven changes in regional rainfall (and some river flows) are expected to emerge from natural variability. Figure 5 shows that for the UK, temperature will be a much stronger climate change signal for some time and that we are unlikely, in most cases, to detect climate-driven trends in river flows for several decades to come (Wilby, 2006).

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  Comprehensive appraisal of water sector risks in all sectors and biomes related to rising air, river, ground, estuarine, and coastal water temperatures.
  
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  Robust statistical techniques for separating climate change signals in “noisy” environmental data sets from natural variability.
  
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  Frameworks for capturing key sources of uncertainty affecting regional climate change scenarios and impacts in the 2020s.
  
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  Integrated tools for demonstrating economic and environmental benefits of adaptation at river basin scales over the next few decades and beyond.
  
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  Data mining and modelling campaigns to test that existing water supply and flood defence infrastructure can cope with the full range of natural variability (especially known historic extremes), as the first step in climate-proofing.
  
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  Better data collection on impacts and responses to current extreme weather events (which are expected to become the normal experience later in the century).
  

Defra, 2005. Adaptation Policy Framework: a consultation November 2005, 37pp.

Romanowicz, R., Beven, K., Wade, S. & J-P. Vidal, 2006. Effect of climate change on river flows and groundwater recharge, a practical methodology: Interim report on rainfall-runoff modelling. UKWIR Report 06/CL/04/7, London, pp71.

Wilby, R.L. & I. Harris, 2006. A framework for assessing uncertainties in climate change impacts: low flow scenarios for the River Thames, UK. Water Resources Research 42, W02419, doi:10.1029/2005WR004065.

Kilsby, C.G., Jones, P.D., Burton, A., Ford, A.C., Fowler, H.J., Harpham, C., James, P., Smith, A. & R.L. Wilby, 2006. A daily weather generator for use in climate change studies. Environmental Modelling and Software, under review.

McKenzie Hedger, M., Connell, R. & P. Bramwell, 2006. Bridging the gap- empowering decision-making for adaptation through the UK Climate Impacts Programme Climate Policy in press.

Environment Agency, 2005. Effect of climate change on salmon fisheries. Environment Agency Science Report W2-047/SR, Bristol, 62 pp.

Wilby, R. L., 2006. When and where might climate change be detectable in UK river flows? Geophysical Research Letters 33, L19407, doi:10.1029/2006GL027552.

Session 5:

Climate change and the water dimension in the MS: research and policy

Case study 3: Netherlands policies and initiatives

Scientists are still debating exactly how things are likely to progress, but one thing is clear: the climate is set to change dramatically under the influence of human activity. As the Dutch Meteorological Office KNMI is already telling us, it is going to rain more often and more heavily in the future. More severe storms are already expected to become a feature of our weather this century. We might perhaps see a few less Elfstedentocht ice-skating marathons, but we can certainly expect more long, hot, dry summers like that of 2003. And also this year a long hot July was followed by an extremely wet month of August.