A new study finds that eating less meat could be a solution to a looming water crisis in a drought-stricken world.
But not all vegetarians are created equal.
The U.S., Africa, and the Middle East would save a significant amount of water if people got their protein from plants. Asia, not so much.
The study, published in the journal Environmental Research Letters, is the first to assess how much water individual countries can conserve if residents eat less land-based animal protein—or none at all.
A third of the planet’s population suffers from water shortages, while about 90 percent of freshwater is used for agriculture. But crops are increasingly grown to feed cows, chickens, and other livestock as the new middle classes in countries such as China and India develop a taste for meat.
“The amount of water that was saved by removing land-based animal protein from the global diet was enough to feed about 1.8 billion more people,” said Mika Jalava, an engineer and a doctoral student at Aalto University in Helsinki, who led the research team.
Using that water to grow more crops for people, not pigs, would help feed a world population expected to reach 9.6 billion by 2050, according to the study.
By using national water footprint data—the volume of freshwater used within the borders of 176 countries—Jalava’s team was able to calculate how much “green” water (rainwater) and “blue” water (rivers, lakes, groundwater) would be affected by a change in diet.
The researchers looked at four scenarios: diets made up of 50 percent less meat, 75 percent less, 87.5 percent less, and 100 percent less. All the diets met World Health Organization nutritional requirements.
If the world’s population went totally veggie, global green water consumption would fall by 21 percent.
Which countries could get back a significant amount of their water from these dietary changes?
“The U.S. is one of those places,” Jalava said. “Saudi Arabia really stands out as well, because they have a very small amount of water resources.”
Israel, Libya, and Spain also would benefit.
“By far the biggest difference is in what are people eating,” Jalava said. “For example, the effects on the water footprints in Asia are really small, as the amount of meat in diets is much lower than in North America, Australia, Western Europe, and South America.”