Green water management to sustain agricultural production in a changing climate
Stockholm Environment Institute
Agricultural production is increasingly water limited in many semi-arid to sub-humid regions. In these regions, climate change is often projected to reduce water availability further, while increasing evaporative demand, variability and extremes, as well as uncertainty in agricultural water management. Conventional blue water solutions and adaptation practices can no longer maintain productivity. In particular further intensification of groundwater pumping and irrigation is not sustainable in many regions of India, China, US and MENA. In order to produce more food for a growing and partially undernourished population, green water solutions have to receive more attention and investment. Green water productivity can be increased by improved land management and well-known practices and interventions that offer multiple benefits, such as conservation agriculture, soil and water conservation, rainwater harvesting and supplementary irrigation. Many of these solutions are more decentralized, smaller in scale and more affordable for the poor than conventional blue water options. With that they can increase diversity and resilience to climate and other disturbances. True integrated water resources management will simultaneously address green and blue water management, e.g. by integrating improved soil and land management with water harvesting and managed aquifer recharge. Finding a way to nest green water management opportunities within the development of blue water management plans is a critical challenge that will be explored.