FAO: Climate change will have major impacts on water for farming
Contact: George Kourous
FAO Media Relations (Rome)
(+39) 06 570 53168
(+39) 348 141 6802
george.kourous@fao.org 9 June 2011, Rome – Climate change will have major impacts on the availability of water for growing food and on crop productivity in the decades to come, warns a new FAO report. Climate Change, Water, and Food Security is a comprehensive survey of existing scientific knowledge on the anticipated consequences of climate change for water use in agriculture. These include reductions in river runoff and aquifer recharges in the Mediterranean and the semi-arid areas of the Americas, Australia and southern Africa — regions that are already water-stressed. In Asia, large areas of irrigated land that rely on snowmelt and mountain glaciers for water will also be affected, while heavily populated river deltas are at risk from a combination of reduced water flows, increased salinity, and rising sea levels. Additional impacts described in the report: An acceleration of the world’s hydrological cycle is anticipated as rising temperatures increase the rate of evaporation from land and sea. Rainfall will increase in the tropics and higher latitudes, but decrease in already dry semi-arid to mid-arid latitudes and in the interior of large continents. A greater frequency in droughts and floods will need to be planned for but already, water scarce areas of the world are expected to become drier and hotter. Even though estimates of groundwater recharge under climate change cannot be made with any certainty, the increasing frequency of drought can be expected to encourage further development of available groundwater to buffer the production risk for farmers. And the loss of glaciers – which support around 40 percent of the world’s irrigation — will eventually impact the amount of surface water available for agriculture in key producing basins. Increased temperatures will lengthen the growing season in northern temperate zones but will reduce the length almost everywhere else. Coupled with increased rates of evapotranspiration this will cause the yield potential and water productivity of crops to decline. “Both the livelihoods of rural communities as well as the food security of city populations are at risk,” said FAO Assistant Director General for Natural Resources, Alexander Mueller. “But the rural poor, who are the most vulnerable, are likely to be disproportionately affected.” Responding to the challenge
FAO’s report also looks at actions that can be taken by national policymakers, regional and local watershed authorities, and individual farmers to respond to these new challenges. One key area requiring attention is improving the ability of countries to implement effective systems for ‘water accounting’ – the thorough measurement of water supplies, transfers, and transactions in order to inform decisions about how water resources can be managed and used under increasing variability. “Water accounting in most developing countries is very limited, and allocation procedures are non existent, ad hoc, or poorly developed,” the report says. “Helping developing countries acquire good water accounting practices and developing robust and flexible water allocations systems will be a first priority.” …
