Water problems exacerbated by rising temperatures threaten global crops

A new report says a quarter of the world’s crops are grown in places experiencing high levels of water stress, unreliable water supplies, or both. The analysis, conducted by research nonprofit World Resources Institute (WRI), highlights the challenge of growing enough food to meet growing demand on a warming planet.

According to a recent United Nations report, one out of every 11 people in the world is hungry, meaning they do not get enough food to maintain basic health. Water issues identified in the latest WRI study could potentially contribute to rising levels of food insecurity, especially as global temperatures continue to rise.

The report looks at both irrigated crops, which transfer water from reservoirs to cropland, and rain-fed crops, which receive water through rainfall. The authors drew on existing WRI data on global water risk and compared them with crop production data from the International Food Policy Research Institute.

Analyzing both sets of data, the report’s authors found that both irrigated and rain-fed crops face challenges when it comes to accessing water. For example, about 60 percent of irrigated crops by weight come from regions of the world experiencing high or extremely high levels of water stress. Water stress means increased competition for water resources; it is considered high if 40 percent or more of a region’s local water supply is used in agriculture, energy, industry, and households.

According to Sam Kuzma, one of the report’s authors, areas experiencing high levels of water stress require robust water management. The problem, she says, stems in part from a general tendency to take water for granted and treat it as an infinitely renewable resource available on demand. “Because we don’t put a value on water, you can irrigate and not pay much at all for the water you use,” said Kuzma, who manages the water data program at WRI. “This means we can be quite reckless with how we grow and in what environments. That’s why you see alfalfa being grown in the desert.”

Most of the world’s irrigated crops—72 percent—are grown in just 10 countries, including Brazil, China, India and the United States, according to WRI. These crops include staple foods such as rice, wheat and corn, which account for a significant portion of the world’s calories.

High levels of water scarcity in areas where irrigated crops are grown poses challenges to global food security. India, for example, is a major agricultural producer and the world’s largest exporter of rice. The country faces significant water risks; About a quarter of total crop production comes from areas that use more water than can be naturally replenished, according to WRI analysis. Kuzma noted that this could lead to groundwater depletion in parts of the country that rely on a water source that “simply won’t be there forever” if current rates of use continue. “If this is a key part of our global food supply chain and we no longer have the water to produce these goods, then, sorry, everyone is affected,” she added.

WRI also looked at the problem of water supply insecurity facing rain-fed crops, which make up two-thirds of the world’s food supply. The analysis found that 8 percent of rain-fed crops by weight face high to extremely high levels of water unreliability due to fluctuations in annual water supply, such as periods of drought and extreme rainfall caused by climate change. As the planet continues to warm, the number of rain-fed crops affected by these conditions could jump 40 percent by 2050 compared to 2020 levels. Rising temperatures can also affect irrigated crops, as crops require more water to survive in hotter climates.

Nicole Silk, global director of freshwater at environmental nonprofit The Nature Conservancy, said these issues are having a severe impact on people and communities. Floods and droughts could put both “people and crop production” at risk, she said. “We are increasingly moving towards a world in which both people and food production will be located in places that are particularly water-stressed,” she added.

As a sector, agriculture is the world’s number one consumer of freshwater, accounting for 70 percent of freshwater abstraction—the process of removing freshwater from surface water sources such as rivers and lakes, as well as groundwater sources such as aquifers horizons. In its latest report, WRI names agriculture as the largest driver of water stress. And yet food has to be grown somewhere, by someone, by someone. Indeed, all signs point to the need to grow more food as the global population is projected to reach 10 billion by 2050. The challenge, then, is how to grow crops without exacerbating the water situation.

“We have to be smarter about what we grow, and we can be smarter about how we grow what we grow,” Silk said. She endorsed some of the measures suggested by WRI as potential solutions, particularly focusing more on soil health (since the more moisture the soil can hold, the less water farmers will have to add to crops). WRI also recommends moving away from meat, which requires huge amounts of land and water to produce, in favor of less water-intensive foods.

Silk also talked about introducing more nature-based solutions, “green” strategies that try to replicate the natural rhythms of an ecosystem, as opposed to “gray” interventions that involve people building new infrastructure. The most effective natural solutions for managing water resources on cropland will vary from place to place, depending on geography, as well as what is being grown. Silk noted that “because water is always on the move,” finding the best management strategies will require taking a step back to see the full picture—for example, reforestation can improve water quality and regulate the water cycle in the landscape. “I think this will end up being a really interesting opportunity for conservationists to meet with farmers and ranchers, meet with local water regulators and utilities, and meet with First Nations and communities,” she said.

Kuzma noted that farmers know better than anyone — and usually before anyone else — about the water issues they face, and that WRI’s analysis is really intended to communicate those risks to a broader audience. And she acknowledged that these management changes and policy recommendations involve asking farmers to “change the way they operate,” which typically requires them to shoulder the financial burden of adapting to climate change alone. “We also need to think about what kind of financial policies and corporate sponsorships we can provide” to make these changes possible, she said.

Silk agreed. “Sometimes farmers and ranchers are willing to change their practices, but they don’t necessarily have the financial resources to do so,” she said. “So if they have an incentive to change this practice or someone else can come and help them, that makes a big difference.”

This article originally appeared in Grist at https://grist.org/article/water-availability-farmers-crops-food-agricultural/.

Grist is a nonprofit, independent media organization telling stories about climate solutions and a just future. Find out more at Grist.org.