Steven Wade

Climate change and water in the UK - past changes and future prospects

Climate change is expected to modify rainfall, temperature and catchment hydrological responses across the world, and adapting to these water-related changes is a pressing challenge. This paper reviews the impact of anthropogenic climate change on water in the UK and looks at projections of future change. The natural variability of the UK climate makes change hard to detect; only historical increases in air temperature can be attributed to anthropogenic climate forcing, but over the last 50 years more winter rainfall has been falling in intense events. Future changes in rainfall and evapotranspiration could lead to changed flow regimes and impacts on water quality, aquatic ecosystems and water availability. Summer flows may decrease on average, but floods may become larger and more frequent. River and lake water quality may decline as a result of higher water temperatures, lower river flows and increased algal blooms in summer, and because of higher flows in the winter. In communicating this important work, researchers should pay particular attention to explaining confidence and uncertainty clearly. Much of the relevant research is either global or highly localized: decision-makers would benefit from more studies that address water and climate change at a spatial and temporal scale appropriate for the decisions they make.

The UK climate change risk assessment 2012: assessing the impacts on water resources to inform policy makers

The Climate Change Act 2008 requires a series of assessments of the risks of climate for the UK, under both current conditions and over the long term, to 2100. This paper describes the research completed on the impacts of climate change on the UK water sector, involving stakeholder engagement and a mix of literature review, expert elicitation and broad-scale quantitative analysis to develop ten climate change risk metrics. These include measures of the demand for water, impacts on supply, water quality and asset performance using future scenarios based on the UK Climate Projections 2009 and future population projections from the Office for National Statistics. The analysis has resulted in a number of key findings that can help to inform policy in different parts of the UK. Overall the assessment showed that there is likely to be increased pressure on water resources in the UK. These pressures need to be considered in long term plans so that the needs of different users are met without impacting on the environment.