Two-thirds of the world’s population, or four billion people, face severe water shortages, according to Dr. Arjen Y. Hoekstra, a professor of water management at the University of Twente in the Netherlands.
“We find that 4 billion people live in areas that experience severe water scarcity at least part of the year, which is more than previously thought, based on those earlier studies done on an annual basis,” says Dr. Hoekstra.
An area experiences severe water scarcity when its farms, industries and households consume double the amount of water available in that area. People in Mexico, the western US, northern and southern Africa, southern Europe, the Middle East, India, China, and Australia are hardest hit.
“That means that groundwater levels are falling, lakes are drying up, less water is flowing in rivers, and water supplies for industry and farmers are threatened,” Dr. Hoekstra said.
The problem isn’t just depleted reservoirs and barren riverbeds; more than 95% of Earth’s liquid freshwater is stored in underground aquifers, and this groundwater is being used far more quickly than it is being replenished.
In January, water crises were rated as one of three greatest risks of harm to people and economies in the next decade by the World Economic Forum, alongside climate change and mass migration.
“Freshwater scarcity is a major risk to the global economy, affecting four billion people directly,” Dr. Hoekstra said. “But since the remaining people in the world receive part of their food from the affected areas, it involves us all.”