In light of the volume of irrigated agriculture globally, and the projected increase in water requirements for food production, increasing water productivity and thus improving the ratio of water used per unit of agricultural output is necessary globally to meet agricultural water demand  . For example, assuming a doubling of global maize production by 2050 increased water productivity could reduce total water consumption compared to the baseline productivity by 20- 60% . Under economic optimisation assumptions, shifts towards less water-intensive and less climate-sensitive crops would be optimal in terms of water use efficiency and absolute yield increases; however, this could pose risks to food security as production shifts away from main staple crops . Shifting currently rain-fed production areas to irrigation will be an important element in ensuring food security with increasing temperatures, though investment in storage capacities to buffer seasonal water shortage will be essential to ensure negative environmental impacts are minimised .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report