Water-Energy-Food Stress, From Fruit to Nuts

Many folks’ thoughts are turning towards global climate change and its seemingly endless list of esoteric or distant problems such as sea water rise, loss in biodiversity, and skinny polar bears swimming endlessly in search for food as they celebrate the 45th annual Earth Day.  Will these almond-crusted granola-crunching mobs also mourn the future of their favored snack?

Detail from pre-climate change, 18th century painting by Antonio Ponce [Public domain],  via Wikimedia Commons

Detail from pre-climate change, 18th century painting by Antonio Ponce [Public domain], via Wikimedia Commons

A recent report by the Intergovernmental Panel on Climate Change lists almonds as one of several agricultural commodities that will be more difficult to grow in a warming world. In a recent report by National Geographic, David Wolfe, professor of horticulture at Cornell University predicts that farmers will likely have to take increasingly drastic and expensive measures to changing climate conditions that are not as simple as gradual warming; this will have an impact on our ability to afford a nutritious diet. An example is the low harvest of apples in 2012 from northern New York caused by an early bloom during unseasonably warm weather and then a late March cold snap.


A highly-charged problem associated with global warming is declining access to safe and reliable fresh water resources. This is not solely a problem of the developing world. The recent draught in California only highlights some of the less esoteric issues of water scarcity in an area that we have come to rely upon for production of nearly half of US-grown fruits, nuts, and vegetables. Major food crops produced in California include, among others, grapes ($4.45 B), lettuce ($1.45 B), tomatoes ($1.17 B), strawberries ($1.94 B), almonds ($4.35 B) and walnuts ($1.35 B); these crops require significant amounts of water to produce (see insert below).  Long-suffering water scarcity, California has already turned to direct reuse of treated wastewater for irrigation of food crops to support food production, food that, in turn, ends up on many of our tables.

The recent draught has also left many dairy farmers in California, the U.S.’s second largest dairy producing state, wondering how they will be able to provide food and water to their milk cows. This prompted a review by a panel of experts that I recently participated in regarding the potential issues that may be associated with direct potable reuse of tertiary treated wastewater for livestock animals as an emergency measure.

It is not clear how future competing demands for high-quality treated sewage will play out among agricultural and public interests seeking direct potable reuse of wastewater in draught-stricken California. There is certainly more to come as the effects of global warming, water scarcity, and impacts on energy and food production (the water-energy-food stress nexus) continues into the future.  Maybe on Earth Day 2024, our thoughts will shift from polar bears to our skinny selves searching through grocery stores for hours for reasonably-priced fruits and nuts?