The effects of climate change due to global warming on river flows in Great Britain

Global warming due to an increasing concentration of greenhouse gases in the atmosphere will affect temperature and rainfall, and hence river flows and water resources. This paper presents results from an investigation into potential changes in river flows in 21 catchments in Great Britain, using a daily rainfall-runoff model and both equilibrium and transient climate change scenarios. Annual runoff was simulated to increase by 2050 by over 20% in the wettest scenarios and decline by over 20% in the driest scenarios - and different catchments respond differently to the same change scenario. Monthly flows change by a greater percentage than annual hows, and under all the scenarios considered there would be a greater concentration of flow in winter. Snowfall, and hence snowmelt, would be almost entirely eliminated. Progressive changes in river flows over the next few decades would be small compared with year-to-year variability, but would be noticeable on a decade-to-decade basis.