Africa-wide “Great Green Wall” to Halt Sahara’s Spread?<\/a><\/p>\nChina built its famous Great Wall to keep out marauders. Now, millennia later, a “Great Green Wall” may rise in Africa to deter another, equally relentless invader: sand.<\/p>\n
The proposed wall of trees would stretch from Senegal to Djibouti as part of a plan to thwart the southward spread of the Sahara, Senegalese officials said earlier this month at the UN’s Copenhagen climate conference.<\/p>\n
The trees are meant “to stop the advancement of the desert,” Senegalese president and project leader Abdoulaye Wade told National Geographic News in Copenhagen.<\/p>\n
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).<\/p>\n
Crops have died and soils have eroded\u2014crippling local agriculture. If the trend continues, the UN forecasts that two-thirds of Africa’s farmland may be swallowed by Saharan sands by 2025 (explore an interactive Sahara map).<\/p>\n
Trees are almost always formidable foes against encroaching deserts, said Patrick Gonzalez of the University of California, Berkeley’s Center for Forestry.<\/p>\n
That’s because stands of trees act as natural windbreaks against sandstorms, and their roots improve soil health\u2014especially by preventing erosion.<\/p>\n
But choosing the right tree species to populate the wall will be crucial to the project’s success, Gonzalez said via email.<\/p>\n
Similar tree-planting efforts by outside agencies have failed, he said, in part because they planted foreign species that soon perished in the harsh desert.<\/p>\n
“We Have to Do What We Have to Do”<\/p>\n
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.<\/p>\n
All 11 countries that would house the Great Green Wall have pledged to help fund the project. <\/p>\n
But the wall has been slow to break ground: Of the 4,350 miles (7,000 kilometers) it needs to cover, only about 326 miles (525 kilometers) have been planted so far, all within Senegal.<\/p>\n
In Copenhagen, President Wade emphasized that he has made the wall a priority, and he has already asked scientists working on the project to choose species hardy enough to survive in arid conditions without maintenance.<\/p>\n
“One thing the president has insisted is \u2026 we have to begin the work now, right now,” added Ndiawar Djeng, advisor to the Senegalese environment minister.<\/p>\n
“If other international committees follow us, that’s OK. If not, we have to do what we have to do,” Djeng told National Geographic News.<\/p>\n
“It’s in the interest of our local people.”<\/p>\n
Farming Boon<\/p>\n
The lush channel through the desert would help farmers already displaced by drought\u2014and may even stem the exodus of “environmental refugees,” organizers say.<\/p>\n
More than 70 percent of Africa’s poor depends on farming, according to the IPCC.<\/p>\n
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.<\/p>\n
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.<\/p>\n
Senegal also plans to dig rainwater reservoirs along its portion of the wall\u2014virtual lifesavers in a region where rain falls only three months out of the year, supporters say.<\/p>\n
“France is helping us by bringing its soldiers, who are working with us planting trees and building reservoirs,” President Wade added.<\/p>\n
The gigantic tree barrier would also trap some atmospheric carbon dioxide, a potent greenhouse gas, and produce a refuge for native animals and plants.<\/p>\n
Some of the trees themselves may become valuable crops.<\/p>\n
The native acacia senegal tree, which is to be a staple plant in the Great Green Wall, produces gum arabic, a main ingredient in consumer products such as cosmetics and soft drinks.<\/p>\n
Farmers could collect the sap and even sustainably harvest some of the wood to make tools or produce charcoal, Senegalese environment advisor Djeng said.<\/p>\n
Local Know-How<\/p>\n
But Senegal may do more for farmers by simply supporting age-old solutions to desertification, UC Berkeley’s Gonzalez noted.<\/p>\n
For example the ethnic groups of the Sahel\u2014a swath of semi-arid savanna on the Sahara’s southern border\u2014have long been successful at reforesting their land using “natural regeneration.”<\/p>\n
In this method, farmers plant small native trees from seeds found in the region and raise the trees in agricultural fields protected from nibbling livestock, Gonzalez said.<\/p>\n
“The Great Green Wall is less feasible than supporting and reinforcing local farmers and the practice of natural regeneration,” he said.<\/p>\n
What’s more, planting trees alone will not stop the Sahara’s spread, according to Matt Brown, senior conservation advisor for the Nature Conservancy’s Africa program.<\/p>\n
Instead, African governments need to find ways to protect existing vegetation and water sources from overuse, Brown said by email.<\/p>\n
Overall, though, the Great Green Wall is an “extremely bold” undertaking, he said, and “sometimes thinking big is what is needed to draw attention to a problem.” <\/p>\n
E. Fudd<\/p>\n","protected":false},"excerpt":{"rendered":"
Works for me! From National Geographic: Africa-wide “Great Green Wall” to Halt Sahara’s Spread? China built its famous Great Wall to keep out marauders. Now, millennia later, a “Great Green Wall” may rise in Africa to deter another, equally relentless invader: sand. The proposed wall of trees would stretch from Senegal to Djibouti as part […]<\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[172,127,175,73,22,7,9,28,8],"class_list":["post-698","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-africa","tag-climate-change","tag-desert","tag-food","tag-forest","tag-green","tag-purpose","tag-science","tag-values"],"_links":{"self":[{"href":"https:\/\/www.greenbelief.com\/index.php?rest_route=\/wp\/v2\/posts\/698","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.greenbelief.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.greenbelief.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.greenbelief.com\/index.php?rest_route=\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/www.greenbelief.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=698"}],"version-history":[{"count":2,"href":"https:\/\/www.greenbelief.com\/index.php?rest_route=\/wp\/v2\/posts\/698\/revisions"}],"predecessor-version":[{"id":715,"href":"https:\/\/www.greenbelief.com\/index.php?rest_route=\/wp\/v2\/posts\/698\/revisions\/715"}],"wp:attachment":[{"href":"https:\/\/www.greenbelief.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=698"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.greenbelief.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=698"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.greenbelief.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=698"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}