The World Meteorological Organization’s (WMO) first State of Global Water Resources report assesses the effects of climate, environmental and societal change on the Earth’s water resources.

The aim of this annual publication is to support monitoring and management of global freshwater resources in an era of growing demand and limited supplies. The report gives an overview of river flow, as well as major floods and droughts. It provides insights into hotspots for changes in freshwater storage.

Currently, 3.6 billion people face inadequate access to water at least a month per year. This is expected to increase to more than 5 billion by 2050. Between 2001 and 2018, 74% of all natural disasters were water related. WMO’s Unified Data Policy seeks to accelerate the availability and sharing of hydrological data, including river discharge and transboundary river basins information.

The cryosphere (glaciers, snow cover, ice caps and, where present, permafrost) is the world’s biggest natural reservoir of freshwater. Mountains are the source of rivers and freshwater supplies for an estimated 1.9 billion people. Changes to cryosphere water resources affect food security, human health, ecosystem integrity and maintenance.

“There is insufficient understanding of changes in the distribution, quantity, and quality of freshwater resources,” said WMO Secretary-General, Professor Petteri Taalas. “The State of Global Water Resources report aims to fill that knowledge gap and provide a concise overview of water availability in different parts of the world. This will inform climate adaptation and mitigation investments as well as the United Nations campaign to provide universal access in the next five years to early warnings of hazards such as floods and droughts.”