What’s 5,000 miles long, stretches from the Atlantic to the Red Sea, and has now secured over $14 billion of investment?

The answer? Africa's Great Green Wall.

But what exactly is it?

And how much progress has been made?

First, the concept.

The aim of The Great Green Wall is to halt desertification by growing the largest living structure on earth.

The planting of a strip of trees and other vegetation stretching from Senegal to Djibouti is intended to trap the sands of the Sahara and protect surrounding land, something that environmental experts say that would restore 100 million hectares of land, provide food security, create jobs, and offer young people an alternative to migration.

Speaking at a January summit in Paris, French President Emmanuel Macron announced that pledges had exceeded the initial target of $10 billion, with development banks and states now pledging over $14 billion over the next four years to protect Africa’s biodiversity.

For some, the acceleration seems long overdue.

Since the birth of the Great Green Wall initiative in 2007, progress has been arguably slow - with only 4% completed.

Speaking at the same event, the chairperson of the African Union Commission Moussa Faki Mahamat urged for more to be done.

''14 years later the launch of this initiative, the dream has faded slightly. Only four million hectares of land have been converted out of the 100 million planned.’’

The extra boost could push the initiative further towards its goal of restoring 100 million hectares of degraded land and creating 10 million green jobs by 2030.

Once complete, the Great Green Wall will be the largest living structure on the planet, three times the size of the Great Barrier Reef.