Betting the farm while irrigation supplies dwindle

One of the editors of a new international agricultural journal recently invited me to write a guest essay about the impacts of climate change and water scarcity on irrigated farmland, which produces nearly 40% of global food supplies. My essay was published last week in Discover Agriculture.

The invitation to write this essay came as a surprise, a challenge, and an opportunity.

It was a surprise because I am by no means an expert on irrigation. Yes, I’ve been fortunate to have worked with very knowledgeable agricultural experts in recent years in publishing a series of papers on agricultural water use (see below), but the motivation behind those papers has been environmental conservation, not farming or food security per se.

Hence, the invitation was a challenge. I needed to learn a lot very fast if I was going to offer a credible account of the state of irrigated farming from a global perspective.

I accepted this challenge because it provided an opportunity to take stock of the food security risk posed by climate change and water scarcity, and to make the case that global food supplies, farmer livelihoods and farm viability, urban drinking water supplies, and the vitality of freshwater ecosystems are all tightly intertwined. In at least two-thirds of the water-stressed basins (rivers, lakes, aquifers) around the globe, you cannot make progress on any of these issues without addressing the use of water in agriculture because irrigated agriculture accounts for nearly 90% of all water consumed on our planet.

The picture I paint in my essay is not pretty. Three-quarters of irrigated farmland suffers from water shortages. One-third of all water use is unsustainable, meaning we are consuming water supplies faster than they are being replenished, resulting in depletion of water stored in reservoirs and aquifers. Climate change is rapidly increasing water risks because of the impact of global warming on water availability. Water scarcity is measurably impacting our food supply, farmer livelihoods, and the economic viability of many farms around the globe.

Our unsustainable overuse of water is also impacting cities that depend on the same water sources as farmers. If water sources are heavily drawn down by irrigation diversions or groundwater pumping, there is less water to support vibrant urban communities and economies.

When the flow of rivers is depleted by diversions to farms and cities, it has a devastating impact on freshwater biodiversity and ecosystem services. Global populations of freshwater animals have declined by 85% over the past half-century, and water depletion is a leading cause.

In closing my essay I struggled mightily to offer hope for the future. As some of my colleagues have said about my usual glass-half-full mentality, “how can you be optimistic when there is so much evidence to the contrary?” The good news is that we have all the know-how and technology we need to feed a growing global population while also sustaining healthy rivers and lakes and wetlands. But the massive challenge is that we desperately lack the leadership, will power, and water governance to bring our knowledge to fruition, and to bring our water use back into balance with nature’s replenishment of our water sources.

It’s often said that people rise to a challenge when their back is against a wall. We’re there now, my friends.

For those interested in other recent work I’ve done with amazing colleagues on water and agriculture:

Richter, B. and M. Ho. 2022. Sustainable Groundwater Management for Agriculture. World Wildlife Fund, Washington DC. https://www.worldwildlife.org/publications/sustainable-groundwater-management-for-agriculture

Richter, B.D.,  K.F. Fowler, G. Lamsal, C.L. Lant, W.J. Ripple, and R.R. Rushforth (2025). Reducing irrigation of livestock feed is essential to saving Great Salt Lake. Environmental Challenges,18. https://doi.org/10.1016/j.envc.2024.101065

Richter, B.D., G. Lamsal, L.Marston, S. Dhakal, L. Singh Sangha, R.R. Rushforth,D. Wei, B.L. Ruddell, K.F. Davis, A. Hernandez-Cruz, S. Sandoval-Solis, and J.C. Schmidt (2024).  New water accounting reveals why the Colorado River no longer reaches the sea. Communications Earth & Environment 5, 134. https://www.nature.com/articles/s43247-024-01291-0

Richter, B.D., E. Prunes, N. Liu, P. Caldwell, D. Wei, K.F. Davis, S. Sandoval-Solis, G.R. Herrera, R.S. Rodriguez, Y. Ao, G. Lamsal, M. Amaya, N. Shahbol. (2023) Opportunities for Restoring Environmental Flows in the Rio Grande–Rio Bravo Basin Spanning the US–Mexico Border. Journal of Water Resources Planning and Management 150(2) https://doi.org/10.1061/JWRMD5.WRENG-6278

Richter, B.D., Y. Ao, G. Lamsal, D. Wei, M. Amaya, L. Marston & Davis, K.F. (2023) Alleviating water scarcity by optimizing crop mixes. Nature Water. https://doi.org/10.1038/s44221-023-00155-

Richter, B.D., D. Bartak, P. Caldwell, K.F. Davis, P. Debaere, A. Y. Hoekstra, T. Li, L. Marston, R. McManamay, M.M. Mekonnen, B. Ruddell, R.R. Rushforth, and T.J. Troy. 2020. Water scarcity and fish imperilment driven by beef production. Nature Sustainability, https://doi.org/10.1038/S41893-020-0483-

Richter, B.D., J.D. Brown, R. DiBenedetto, A. Gorsky, E. Keenan, C. Madray, M. Morris, D. Rowell, and S. Ryu. 2017. Opportunities for saving and reallocating agricultural water to alleviate scarcity. Water Policy,  https://doi.org/10.2166/wp.2017.143