A new global overview of the impact of agricultural trade on groundwater, food security, and energy use has been launched by professors Cecilia Tortajada and Francisco González-Gómez.
The research assesses global trends in groundwater-based, export-oriented agriculture, and highlights its role in aggravating groundwater depletion as well as national energy use.
The use of groundwater has facilitated a doubling in international trade in food and agricultural products since 1995. It has also enabled a 55 percent increase in global production of primary agricultural products between 2000 and 2019. This expansion was made possible in large part due to the use of external inputs such as irrigation water, fertilisers and pesticides as opposed to improved farming practices and high yield crops.
In total, approximately 30 percent of the global land area used for irrigated agriculture depends on groundwater. The authors note a clear global trend towards the expansion of irrigated areas for export agriculture, which increases productivity but also results in groundwater depletion.
The article cites examples from India, the United States, Mexico, Peru and Spain to illustrate the overdrafts on sustainable groundwater supply. In spite of some increases in overall production efficiency, increases in production have continued to place pressure on groundwater resources. There is, in fact, a rebound effect at work that encourages the use of more land, more water, and more fertilisers.
Groundwater use also consumes 30 percent more energy than surface water. Energy subsidies for agricultural water pumping has served to hide the real economic and environmental cost of groundwater. At the same time, despite encouraging recent advances, the protection of groundwater is undermined by poor regulation, policy, management, and governance.
The authors therefore argue that groundwater governance mechanisms with joint management of resources are urgently needed. So too are appropriate forms of shared decision making at national and local levels around broadly agreed goals.