The Great Green Wall may be the most aptly named thing ever. It's great, stretching nearly 5,000 miles across the continent of Africa. It's green, consisting of millions of trees. And it's a wall — not a solid wall, but a wall of trees meant to keep the Sahara from encroaching further into communities as a result of climate change and desertification.

It has been under construction for a decade and is about 15 percent done. Once completed, it will be the largest living structure on the planet at three times the size of the Great Barrier Reef.

The Great Green Wall is rooted in Africa's Sahel region, which is the southern border of the Sahara. It stretches through at least 20 nations, some of them among the poorest in the world, including:

  • Senegal
  • Mauritania
  • Mali
  • Burkina Faso
  • Niger
  • Nigeria
  • Chad
  • Sudan
  • Eritrea
  • Ethiopia
  • Djibouti

The Wall's ultimate ambition

Great Green Wall The Great Green Wall is rooted in Africa's Sahel region, which is the southern border of the Sahara. (Photo: Great Green Wall)

Millions of residents in these nations are hard-hit by the effects of climate change, such as droughts, famine and conflict over natural resources, which has led to mass migrations overseas.

"By 2020 an estimated 60 million people could move from the desertified areas of sub-Saharan Africa towards North Africa and Europe. By 2050, 200 million people may be permanently displaced environmental migrants," according to a report by the United Nations Convention to Combat Desertification.

Some of those migrants die in overcrowded boats attempting to cross into Europe. Others arrive but are immediately arrested and jailed. The hope is that the Great Green Wall will boost food production, limit conflicts over natural resources, and improve job prospects so that people will stay. By 2030, the Wall hopes to restore 100 million hectares (or 247 million acres) of degraded land and create 10 million jobs.

However, as The Guardian reports, the opposite could happen:

While donors hope the project will encourage would-be migrants to enjoy better conditions at home, some migration experts say such development policies might have the opposite effect. With a little more money in peoples’ pockets, migration becomes more tenable.

The Wall, as it stands

African women working in agriculture The hope is that the Great Green Wall will boost food production and improve job prospects so that people will stay in Africa. (Photo: Great Green Wall)

Because the Wall touches so many nations, it can be tricky to proceed in a unified way. Different nations have adopted their own initiatives to combat desertification and have committed to the Wall in varying degrees. The project now "consists of a mosaic of projects implemented by over 20 countries in the region," according to the International Tree Foundation (ITF).

Still, the progress so far has been encouraging. The ITF provides these highlights:

  • In Ethiopia, 15 million hectares (37 million acres) of degraded land have been restored.
  • In Nigeria, 5 million hectares (12 million acres) of land have been restored.
  • In Sudan, 2,000 hectares (5,000 acres) of land have been restored.
  • Senegal has planted over 12 million trees.
  • In Burkina Faso, the tree population has increased by over 3 million.

With more than $8 billion pledged for the Wall, according to The Telegraph, there are even more trees to come.

Angela Nelson ( @bostonangela ) is an exhausted mom of two young daughters and two old cats, and a Pulitzer Prize-winning digital editor with more than 15 years of experience delivering news and information to audiences worldwide.

Can Africa's Great Green Wall combat climate change and mass migration?
The Great Green Wall is rooted in Africa's Sahel region on the southern border of the Sahara. Once completed, it will be the largest living structure on Earth.