The Green Wall for the Sahara Initiative will plant a wall of trees to stop the spread of the Sahara. Photo: Dale Gillard (flickr)

Ever heard of the Great Green Wall?

Concerns about the rapid southern spread of the Sahara desert have prompted African nations to build a wall – out of trees.

The Sahara has been moving south at a rate of almost a square kilometer a year, consuming villages and wiping out agricultural lands.

Slowing the desertification has become a huge priority — and a huge community effort.

International aid groups are helping build community gardens, institute new irrigation techniques, and teach sustainable farming. Projects are especially successful in the areas of the Sahara, like northern Burkina Faso, where new farming techniques are taking advantage of increased rainfall due to climate change.

The biggest project to date is the Green Wall for the Sahara Initiative. The $3-million, two-year initial phase will plant a belt of trees 7,000-kilometers long and 15 kilometers wide, and was formally approved at the Community of the Sahel-Saharan States in Benin last month.

The African Union says future phases will plant trees from Mauritania to Djibouti in two parallel belts, creating a strip of protected topsoil for high-yield farming. Nigeria has launched its own complimentary Desert-to-Food Program.

The AU hopes the Green Wall Initiative will arrest soil degradation, reduce poverty, conserve biodiversity, and increase land productivity in more than 25 countries. Others hope the project will create millions of jobs, promote ecotourism, alleviate the food crisis, and even introduce new fishing and livestock-breeding industries.

Who would have thought a wall of trees could have such a big impact?

Social entrepreneur Steven Redgrave gained renown by winning gold medals in rowing in five consecutive Olympics from 1984 to 2000. After retiring from competition, Redgrave was knighted in 2001, launched a line of men’s leisurewear and started a charitable trust focusing on educational and social needs in the UK.

In 2005 he visited Africa, and was moved to action by the poverty he observed. With the help of a major British retailer, Redgrave relaunched his clothing line, FiveG (short for "Five Gold"), as a 100-percent fair-trade enterprise.

In this video diary, produced by Fairtrade Foundation, we follow Redgrave as he visits a rural farming community in Mali that produces cotton for his products.

Thanks to fair trade, not only do these rural farmers receive a higher wage, but their community as a whole benefits as well. The video explains how the community receives what is called a "social premium" that is used for community development projects, including a new health center and a primary school.

For an in-depth look at fair-trade cotton, check out this analysis from the Center for Strategic and International Studies in our archives.