Water levels in rivers and aquifers will decline in semi- arid regions of the Americas, Australia and southern Africa, which are already dry, the Rome-based FAO said in a report today. In Asia, crop-growing areas that rely on snowmelt and mountain glaciers for water will also be affected, it said.
Drought already threatens crops in China and France, helping to push up wheat prices in Paris by 85 percent in the past year. Costlier food has contributed to riots across northern Africa and to inflation, leading central banks in at least two dozen countries to raise interest rates this year.
“Climate change will have major impacts on the availability of water for growing food and on crop productivity in the decades to come,” the FAO said. “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.”
Increased global temperatures will lengthen the growing season in northern growing areas and reduce it for the rest of the world, according to the report. Water evaporation caused by rising temperatures will lead to lower crop yields and reduced production, the UN said.
The “loss of glaciers” that support 40 percent of the world’s irrigation will affect the amount of surface water available for agriculture, the FAO said. Heavily populated river deltas are at risk of reduced water flows, increased salinity and rising sea levels, according to the FAO.
To reduce the damage of climate change, countries can account for their water by measuring supplies and growers can conserve soil moisture through better farming practices, according to the report.
“At the farm level, growers can change their cropping patterns to allow earlier or later planting, reducing their water use and optimizing irrigation,” the FAO said. “Yields and productivity can be improved by shifting to soil moisture conservation practices.”
World food production will have to rise 70 percent by 2050 to feed a population forecast to grow to 9 billion people, the FAO has said.
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