The evidence

The hydrological cycle continuously replenishes the world¿s water resources and is the foundation of life on earth. Now we find that a combination of natural and human activities is having a disturbing influence on the cycle. Dramatically changing weather patterns mean that the replenishing water arrives as intense rainfall, overwhelming flood defences and escaping to the ocean before it can be stored to quench thirsts, irrigate crops, sustain ecosystems, drive hydroelectric turbines or meet the needs of industry. Distinguishing long-term climate change (CC) from short/medium-term climate variability (CV) is the first step in understanding and tackling our vulnerability to extreme weather events like typhoons, floods and droughts. In Chapter 1, graphs, charts and examples illustrate the way that weather patterns are changing. As our understanding of El Niño, La Niña and other climate-varying phenomena gets better, can we find better ways to cope with the resulting weather extremes? What will the trends towards more extreme weather mean for today¿s and tomorrow¿s water managers? Forecasting next week¿s weather and next season¿s climate is a crucial part of disaster preparedness and long-term planning. How good are the forecasts and the modelling systems, and do they really meet the needs of water managers? What we find is that scientists feel more confident about predicting what the world¿s climate might be like in 50 or 100 years time for different development scenarios than they do about forecasting when the next drought might hit Kenya. Which is not the way that Kenya¿s long-suffering farmers would prefer it