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WATER RESOURCES/
QUALITY
source: www.thewaterpage.com/
climatech_fact_sheet13.htm
www.unep.org/themes/climatechange/
PDF/ipcc_wgii_guide-E.pdf
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Changes to the earth's climate have a direct effect on the global hydrological cycle and hence on water…- climate change will lead to more precipitation - but also to more evaporation. In general, this acceleration of the hydrological cycle will result in a wetter world. Some scenarios suggest that 10% of the Earth’s surface area would be subject to water stress;
- changing precipitation patterns will affect how much water can be captured. Several models suggest that downpours will become more intense. This would increase floods and runoff while reducing the ability of water to infiltrate the soil. Changes in seasonal patterns may affect the regional distribution of both ground and surface water supplies;
- reservoirs and wells would be affected. Changes at the surface would influence the recharging of groundwater supplies and, in the longer term, aquifers. Water quality may also respond to changes in the amount and timing of precipitation;
- above 2 to 2.5°C global average temperature increase, it is projected that an additional 2.4 to 3.1 billion people will be at risk of water stress;
- in Africa’s large catchment basins of Niger, Lake Chad and Senegal, total available water has decreased by 40 - 60%;
- an intense summer storm over London in 2004 caused sewers to overflow directly into the Thames estuary;
- livelihoods are increasingly affected by hydro-meteorological disasters. In the 1990s, 500,000 people lost their lives to these events, and over 2 billion more were affected. During the decade 1991-2000 more than 90% of the people killed by natural hazards lost their lives as a consequence of extreme hydrological events;
- by 2050 over 2 billion people are expected to be affected annually. It is the poor who are the most vulnerable and suffer the greatest.
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