杏吧原创

As many as 5 billion people could be denied a regular supply of water by 2050, warns UNESCO in its . Currently, 3.6 billion鈥攈alf the world鈥檚 population鈥搇ive in areas that are water-scarce at least one month a year, and this is set to rise as the population approaches 10 billion.

But shortages could be eased if countries use natural methods to conserve and trap more water in soil, wetlands and vegetation, rather than relying solely on human-made infrastructure such as reservoirs, irrigation channels and water treatment plants. As many as 1.7 billion people could benefit, says .

鈥淚f we do nothing, some five billion people will living in areas with poor access to water by 2050,鈥� says , director-general of UNESCO. 鈥淭his report proposes solutions that are based on nature to manage water better.鈥�

The report says that 鈥済reen infrastructure鈥� alone聽can鈥檛 solve shortages, but where it is being deployed alongside 鈥済rey infrastructure鈥� to supplement and safeguard water supplies. It estimates that agricultural production could be boosted by as much as 20 per cent globally if nature-based solutions are fully adopted.

Green solution

Both farmers and drought-hit city-dwellers could benefit, say UNSECO. One study looking at agricultural projects deploying natural water harvesting measures in 57 low-income countries found crop yields increased by 79 per cent.

New York City, meanwhile, has been enjoying the benefits of the largest unfiltered water supply in the USA by protecting and extracting water from its natural reservoirs since the 1990s, saving $300 million each year on water treatment and maintenance costs.

And in China, the government plans to build 16 pilot 鈥渟ponge cities鈥� by 2020 which will aim to recycle 70 per cent of rainwater through better soil permeation, retention and storage, alongside restoration of adjacent wetlands.

Restoring natural elements of the landscape such as flood plains could also help buffer predicted increases in floods and droughts as climate change becomes more pronounced. The report says that by 2050, 1.6 billion will be at risk of floods, up from 1.2 billion today.