Water use has been growing at more than twice the rate of population increase in the past century – to the point that now about 1.2 billion people lack access to safe drinking water; another 3 billion do not have adequate sanitation.

Further, as climate change alters weather patterns, areas such as the Mediterranean region and Southern Africa may face reduced rainfall – placing the 1 billion people who live in these already dry regions at risk of increased water scarcity.

For people in more than one-third of the World’s largest cities – including Jakarta, Bogotá and Mexico City – clean water starts in protected forests, where water is captured, stored and purified.

Rivers, lakes and irrigation systems stay filled only when those upstream trees are left standing – but deforestation and land-use conversion from forest to agriculture and development pose serious threats to critical watersheds around the World, reducing the supply of water for millions of people.

Our pale blue dot seems covered in abundant water – but of all that blue, only 3% is fresh, and of that, only 1% is found in accessible lakes, rivers and underground sources; the rest is frozen or too deep underground for humans to reach.

As the global population grows, so does demand for fresh water. Many water systems around the World have already collapsed – and according to one estimate, by 2030 the global demand for water will outstrip supply by 40%.