Droughts and extreme rainfall events are wreaking a heavy toll on lives and economies. Melting snow, ice and glaciers have increased hazards like floods and threaten long-term water security for many millions of people.

And yet, far too little is known about the true state of the world’s freshwater resources. We cannot manage what we do not measure. There must be improved monitoring, data-sharing, cross-border collaboration and assessments of water resources – and an accompanying increase in investments to facilitate this. This is vital to help society cope with increasing water extremes of too much or too little, it says.

The WMO State of Global Water Resources Report 2022 builds on a pilot issued last year. It contains more expanded information on important hydrological variables like groundwater, evaporation, streamflow, terrestrial water storage, soil moisture, cryosphere (frozen water), inflows to reservoirs, and hydrological disasters. It integrates field observations, satellite-based remote sensing data and numerical modelling simulations to assess water resources at the global scale.