Making drinking water out of seawater is a growing trend but a potential threat to the environment that could exacerbate climate change, according to WWF, a prominent conservation organization.

The WWF review, Making water: Desalination – option or distraction for a thirsty world?, shows that some of the driest and thirstiest places are turning to desalination.

“Desalinating the sea is an expensive, energy-intensive and greenhouse gas emitting way to get water,” says Jamie Pittock, a WWF director. “It may have a place in the world's future freshwater supplies, but regions still have cheaper, better and complementary ways to supply water that are less risky to the environment.”

It is estimated that around 60 percent of freshwater needs in the Arabian Gulf are met through desalination, and the Australian city of Perth may be looking to source one-third of its freshwater the same way. Spain is devoting an astonishing proportion of its desalinated water to agriculture – at 22 percent, the highest level in the world – as well as to holiday resorts in arid areas.

Impacts of desalination include brine build-up, increased greenhouse gas emissions, destruction of prized coastal areas and reduced emphasis on conservation of rivers and wetlands. Many of the areas of most intensive desalination activity also have a history of damaging natural water resources, particularly ground water.