Aquifer Overdraft and Food Security
Water security and food security are firmly linked because all crops produced for human and animal food require water in an amount needed to produce a profitable and sustainable yield. Plus, 1) irrigated agriculture contributes significantly to worldwide food production, and 2) since water alone is also needed by both humans and animals, water security is arguably more important than food security. Regardless of which is more important, it is safe to say that all animals on the planet need both water and food to survive and develop normally.
In an article by Perez et al. titled “Ending groundwater overdraft without affecting food security“, the following points are presented regarding the use/overuse of groundwater [GW] to produce food.
• The managed use of GW is a key to accelerating agricultural growth and achieving food security for the world’s increasing human population.
• GW depletion over the last several years has resulted in the degradation of many underground water sources.
• Halting or significantly reducing GW depletion without concurrent policy actions would adversely affect food production and supply.
• Solar-driven irrigation pumps reduce greenhouse gas emissions, but likely encourage more rapid GW use and depletion.
• GW is increasingly being used for irrigation of crops since 1) rainfed agriculture results in erratic and unpredictable production, and 2) surface water availability for irrigation is becoming increasingly less dependable.
• Increasing GW depletion is a major challenge to global food security, especially with an increasing world population needing more and more food.
• Most of the world’s river basins with GW supplies are over-exploited.
• There is the potential for future GW exploitation of not-yet over-exploited aquifers in the world.
• Halting GW depletion will reduce agricultural production, which will increase food prices and subsequently result in an increasing number of people being at risk of hunger.
• Interestingly, one of the scenarios that is proposed to remedy GW depletion is for people in high-income countries [HIC] to reduce their consumption of meat products, which the authors project will reduce the demand for GW-fed animal feeds such as corn.
• Increased investment in the development of ways to improve the effective use of precipitation offers a viable policy alternative to that of increasing the water use efficiency [WUE] of irrigated crops.
• The authors question whether or not GW depletion can even be curtailed or halted, likely because of the slow recharge of depleted aquifers compared to the past, present, and projected future rates of water withdrawal from those aquifers.
• Achieving more sustainable GW management will require changes in/enactment of government policies plus a larger investment in research and development that should result in technologies that will improve crop plants’ WUE. These should be coupled with the curtailment of increasing human population on the planet [this begs the question “has the ‘carrying capacity’ of the planet been exceeded in terms of human population?”].
Final thoughts: 1) Is it possible that there are more people both now and in the future than the planet can support with current known resources? 2) Will people in HIC’s be willing to change their eating habits so that the people in low-income countries will have a dependable and sustainable food supply? 3) Will current and future GW conservation efforts be enough to ensure a sustainable food supply for an increasing world population?
Composed by Larry G. Heatherly, July 2024, larryh91746@gmail.com