To thwart the southward spread of the Sahara desert Senegalese officials are proposing to build a wall of trees that would stretch from Senegal to Djibouti as part of a plan.
The trees are meant "to stop the advancement of the desert," Senegalese president and project leader Abdoulaye Wade told National Geographic News during UN's Copenhagen climate conference.
In many central and West African countries surrounding the Sahara, climate change has slowed rainfall to a trickle, according to the UN's Intergovernmental Panel on Climate Change (IPCC).
Crops have died and soils have eroded, crippling local agriculture.
If the trend continues, the UN forecasts that two-thirds of Africa's farmland may be swallowed by Saharan sands by 2025.
"Trees are almost always formidable foes against encroaching deserts," said Patrick Gonzalez of the University of California, Berkeley's Center for Forestry.
That's because stands of trees act as natural windbreaks against sandstorms, and their roots improve soil health, especially by preventing erosion.
"But, choosing the right tree species to populate the wall will be crucial to the project's success," Gonzalez said.
"Similar tree-planting efforts by outside agencies have failed, in part because they planted foreign species that soon perished in the harsh desert," he added.
Nigerian President Olusegun Obasanjo first proposed the idea of a desert-blocking wall in 2005, and it was approved by the African Union in 2007.
All 11 countries that would house the Great Green Wall have pledged to help fund the project.
The lush channel through the desert would help farmers already displaced by drought-and may even stem the exodus of "environmental refugees," according to the organizers.
More than 70 percent of Africa's poor depends on farming, according to the IPCC.
But, drought, desertification, and other climate-related disasters are forcing many farmers to abandon their lands, spurring a heavier flow of immigrants out of central and North Africa.
The 9.3-mile-wide (15-kilometer-wide) wall of trees would improve the surrounding, now-degraded soils, allowing farmers to again grow crops and more easily raise livestock in the region.
Senegal also plans to dig rainwater reservoirs along its portion of the wall-virtual lifesavers in a region where rain falls only three months out of the year.
The gigantic tree barrier would also trap some atmospheric carbon dioxide, a potent greenhouse gas, and produce a refuge for native animals and plants.