Overview
- The UNU‑INWEH assessment finds roughly three‑quarters of people live in water‑insecure countries and about 4 billion face severe scarcity for at least one month each year.
- Evidence cited includes long‑term declines across about 70% of major aquifers, significant volume losses in roughly half of large lakes, and widespread wetland disappearance.
- Urban systems are straining, with reporting that half of the 100 largest cities face extreme shortages and Day Zero risks flagged for cities such as Chennai and Tehran.
- Authors attribute worsening shortages to climate warming interacting with chronic mismanagement, pollution and land‑use change, contributing to subsidence, sinkholes and agricultural stress.
- The report calls for protecting remaining natural water capital, stronger global monitoring and agricultural reforms, and its framework is set to shape Dakar preparatory talks for the 2026 UN Water Conference, with UNU noting recent U.S. withdrawal moves have not yet disrupted operations.