5.6A - Inputs and Outputs
Climate change affects inputs and outputs within the hydrological cycle: trends in precipitation and evaporation
Precipitation
- A warmer atmosphere has a greater water-holding capacity
- It is argued that the mode of precipitation may be more important than the amount in determining the impacts
- Widespread increases in rainfall intensity are expected more than large increases in total amounts
- Areas of precipitation increase include the tropics and high latitudes
- Areas of precipitation decrease lie between 10° and 30° north and south of the Equator
- The length and frequency of heatwaves is increasing in some locations and is resulting in the increased occurrence of drought
- With climate warming, more precipitation in northern regions is falling as rain rather than snow
Evaporation and Evapotranspiration
- Evaporation over large areas of Asia and North America appears to be increasing
- Transpiration is linked to vegetation changes, which in turn are linked to changes in soil moisture and precipitation