Water is one of the essential elements to life on Earth. Our planet’s water cycle drives our weather and climate. Water is indispensable to our social and economic well-being.

Some 70% of planet Earth is covered in water, 97% of that water is in the oceans and only 3% is fresh water. But two thirds of that fresh water is locked in glaciers in the Arctic and Antarctic, leaving only 1% in mostly ground water and a very small fraction in our lakes and rivers.

Mountainous regions – often referred to as Water Towers of the world – cover about a quarter of the Earth’s land surface and are important sources of freshwater. Billions of people around the world use waters from mountain river sources for agriculture, forestry, food production, fisheries, hydro-electric power production, transportation, tourism, recreation, infrastructure, domestic water supply and their health. The Third Pole (TP) alone – it encompasses the Tibetan Plateau, the Himalayas, the Hindu Kush, the Pamirs and the Tien Shan Mountains – supports a population of 1.7 billion and has a gross domestic product (GDP) of US$ 12.7 trillion.

Rising global temperatures are causing changes to meteorology, hydrology and ecology, including the cryosphere – snow, glaciers, frozen ground on high mountain tops and the poles.  Risks related to natural hazards, environmental alterations and the loss of critical ecosystems are increasing for local, downstream and coastal populations.  Uncertainty in water availability increases vulnerability and brings significant economic risk.

The world’s 6.7 billion people consume about 4 500 km3 (4.5 teralitres) of freshwater annually. Approximately 10% is for domestic use, 70% is for food production and 20% is for industrial purposes. Freshwater precipitation makes up 2.5% of the available resource and much of that falls in remote areas, leaving only 10% of the total continental precipitation input as easily available for human use (about 9 000–12 000 km3).

Source: Water Prospects in the 21st Century (2010)

Effective, sustainable management of water resources requires transboundary collaboration along river basins as well as international collaboration. Efficient water management to meet the needs of all sectors requires that hydrometeorological data and information systems be combined with social, economic and environmental data. Investments in water management protect our natural resources and global stability. Constructive, inclusive participation in effective water management builds public trust.

WMO and its partners are implementing effective, sustainable and efficient hydrometeorological services for water management at the local, transboundary basin, regional and global levels.