A conference of water experts meeting in Bonn, Germany, has issued a warning that, without major reforms, "in the short span of one or two generations, the majority of the 9 billion people on Earth will be living under the handicap of severe pressure on fresh water, an absolutely essential natural resource for which there is no substitute.
"This handicap will be self-inflicted and is, we believe, entirely avoidable," the statement said.
The concern now extends far beyond "classic" drinking water and sanitation issues and includes water quality and quantity for ecosystems at all scales, a release from the Global Water System Project, based in Bonn, said.
The effect on water supplies of mismanagement, overuse and climate change pose long-term threats to human well-being, the researchers said.
"The list of human activities and their impact on the water systems of planet Earth is long and important," project executive officer Anik Bhaduri said.
"Humans are changing the character of the world water system in significant ways with inadequate knowledge of the system and the consequences of changes being imposed," he said.