50bn tonnes of sand and gravel extracted each year, finds UN study

A front loader is used to clear and area for sand mining on a dried lake bed in Jiangxi province, China. Photograph: Aly Song/Reuters

Humans extract 50bn tonnes of sand and gravel every year, according to UN research, enough to build a wall 27 metres high by 27 metres wide around the planet.

Sand is the most-exploited resource after water. But unlike water, it is not recognised as a key strategic resource by governments and industry, something, the UN says, that must change and fast.

The UN report makes the case for greater monitoring of extraction and supply chains, measures to compensate for the associated loss of animal and plant species as well as the uneven social and economic impacts of sand mining.