The world’s hottest desert in the world is also one of the largest, covering an area that stretches across the North of Africa from the Red Sea in the east to the Atlantic in the west. In total, it spans 9,400,000 sq km (3,500,000 sq mi) - nearly as big as China or the United States.

In the searing heat of the day it is hard to imagine a more desolate place. But hidden within the vast dunes and swathes of dust are minerals left from an earlier, more fertile time when the region was home to agriculture, along with plants and animals now more commonly found in the savannahs further south.

Today, these minerals continue to support life. But to do that they must first go on an extraordinary journey.

Blown up into the high atmosphere, this dust is carried across the Atlantic where it falls with the rain across the Amazon rainforest, injecting much needed nutrients into this bio-diverse ecosystem.

In this film Charlie Bristow, Professor of Sedimentology at Birkbeck College, Dr M Sanjayan lead scientist at The Nature Conservancy, and environmental economist Pavan Sukhdev reveal not only the natural beauty of the Sahara but also its hidden ability to nourish ecosystems round the planet.

If you would like to comment on this video or anything else you have seen on Future, head over to our Facebook page or message us on Twitter.