UN: half world's population to face water stress by 2030

Almost half the world's population will live in areas of high water stress by 2030 as a result of climate change, according to a new report this week from the UN, which urged political and business leaders to increase investment in water infrastructure or risk economic activity and development goals being seriously undermined.

Released at the annual World Water Forum in Istanbul, the World Water Development report warned that the combination of climate change, population growth, and increased demand for food, energy and biofuels meant that in a little more than two decades 47 per cent of the global population would be living in areas of high water stress.

It also warned that "some countries are already reaching the limits of their water resources", resulting in an intensification of competition for water resources that threatens to stoke conflicts and make water supplies an " increasingly politicised issue".

Speaking at the conference in Istanbul, Koïchiro Matsuura, director general of the UN Educational, Scientific and Cultural Organisation (UNESC), said that the threat of water scarcity could become "insurmountable" if action is not taken quickly to increase investment in improved water infrastructure.

"With increasing shortages, good governance is more than ever essential for water management," he said, adding that development efforts to combat poverty were also dependent "on our ability to invest in this resource".

The report warned that a number of factors are combining to increase demand for water at a time when climate change means more regions are likely to face prolonged droughts.

According to the report, population growth combined with increased demand for meat and dairy products means demand for water from the global agricultural sector is expected to increase by between 70 and 90 per cent by 2050.

Meanwhile, increased demand for biofuels has also put pressure on water resources in countries such as the US and Brazil, with an estimated 1,000-4,000 litres of water required to produce a single litre of biofuel. The report concludes that "despite their potential to help reduce dependence on fossil energy, biofuels, with current technology, are likely to place a disproportionate amount of pressure on biodiversity and the environment".

Similarly, the report warns that an expected 60 per cent increase in hydroelectric power capacity between 2004 and 2030 will increase pressure on water resources in countries such as China and India.

The report concludes that these risks mean there is a strong economic case for investing in water infrastructure, calculating that each dollar invested in improving access to water and sanitation will deliver a boost to GDP of between $3 (£2.14) and $34.

It also argues that there are numerous cost-effective initiatives that can be undertaken to tackle water scarcity, noting that in the Mediterranean region an estimated 25 per cent of water in urban areas and 20 per cent of water in irrigation canals is lost through leakage.