Water Risk to Agriculture in Central America

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1 World Resources WRI Water Risk to Agriculture in Central America September 24 and 25 (c) WRI/Moray McLeish

2 DROUGHT IN CENTRAL AMERICA Guatemala s and El Salvador s crop losses were as high as 70% and 60%, respectively In Nicaragua, thousands of cattle died and price of corn and beans have quadrupled Panama s Canal Authority threatened to restrict ship traffic do to low levels in lakes NPR, August 29, 2014

3 WATER RISKS TO AGRICULTURE Uncertainty in water supply and availability due to climate change Uncertainty in water demands by other sectors Agriculture is the largest consumer of water in Latin America

4 BARRIERS TO ACTION Lack of climate change and socio-economic growth scenarios Lack of information on baseline water conditions Inadequate water governance IICA Workshop, July 3, 2014

5 OPEN ACCESS TOOL

6 SCENARIOS FOR PROJECTED CHANGE IN WATER SUPPLY AND DEMAND Optimistic scenario RCP4.5/SSP2, cautiously optimistic RCP4.5, cautiously optimistic 4.5 W/m2 radioactive forcing 650 CO2 ppm, >2.5 C by 2100 SSP2, business as usual for population growth, economic growth, and urbanization Business-as-usual scenario RCP8.5/SSP2, present trends will continue RCP 8.5, business as usual 8.5 W/m2 radioactive forcing 1,370 CO2 ppm, >4 C by 2100 SSP2, business as usual Pessimistic scenario RCP 8.5/SSP3, worst case RCP 8.5, business as usual 8.5 W/m2 radioactive forcing 1,370 CO2 ppm, >4 C by 2100 SSP3, unmitigated emissions are high

7 PROJECTED CHANGE IN WATER SUPPLY AND DEMAND Climate data From an ensemble of 6 CMIP5 GCMs following carbon emissions scenarios (RCPs) Water supply Crop evaporation rates Water demand data Driven by assumptions of population, economic growth, and urbanization (SSPs) Competition from other sectors Following slides assume business as usual emissions and economic growth (RCP8.5 SSP2)

8 Higher global temperatures will increase amount of water needed by crops Water demand expected to outpace changes in soil water availability Increases irrigation requirement Reduces rain-fed productivity DRAFT

9 All parts of Central America are expected to have higher crop water demand Mean change in crop water demand in rainfed lands by 2040 Equivalent to decrease of 20-50mm/year in rainfall Change in average annual PET-AET from assuming business as usual emissions (RCP8.5) DRAFT

10 Economic and population growth and climate change will affect availability of water for irrigation Mid-latitudes expected to lose water supply while low latitudes to gain supply DRAFT

11 Central America are expected to face greatest rates of increased competition for water Median change in water stress in irrigated lands by 2040 Increased municipal and industrial water use may shift water away from irrigation Change in ratio of average annual withdrawal to supply from assuming business as usual emissions and economic growth (RCP8.5 SSP2) DRAFT

12 Greater differences between wet and dry seasons expected Many regions may see more severe differences in water availability between months of the year DRAFT

13 Central America should expect mild to moderate increases in seasonal variability Median change in seasonal variability of supply in irrigated lands by 2040 Expect drier dry seasons and higher runoff and erosion potential in wet seasons Change in within-year coefficient of variance of monthly water supply from assuming business as usual emissions (RCP8.5) DRAFT

14 USE OF PROJECTED CHANGE IN WATER SUPPLY AND DEMAND Understand future water stress for planning and zoning Understand future water stress to address vulnerability to large scale irrigation projects Understand future crop yields and losses to safe guard food security

15 RECOMMENDATIONS I. Understand risks and vulnerabilities Working with key stakeholders across sectors, develop estimates of future water supply and demand at a river basin scale, and promote the collection of robust farmlevel soil and water data to help identify key vulnerabilities of the agricultural sector and the associated risks to long-term water security II. Increase investments in research, technology and capacity building Support the development and implementation of agricultural technologies and practices and build capacity to improve the integrated management of water resources and help the agricultural sector continue to adapt to changes in water availability while improving crop productivity. III. Improve water demand managment working across sectors In collaboration with agriculture, businesses and municipalities within a watershed, minimize the demand for freshwater and seek new opportunities for collaborative solutions to reduce pressures on water resources.

16 (c) WRI/James Anderson Muchas gracias Tien Shiao Paul Reig Francis Gassert DRAFT