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A Great Green Wall for Africa?

If a metaphorical wall of trees gets built as grassroots activists envision, it could help save the continent from hunger, poverty and climate change.

Mark Hertsgaard

November 2, 2011

At first the women weren’t sure they could do it. Or should do it. Many in the village agreed. Digging holes, planting trees, being leaders—weren’t these men’s jobs?   “Everyone said we were crazy,” recalls Nakho Fall, a stocky, vivacious woman in a red-and-white print dress. With a dozen women neighbors and their children, Fall is seated beneath a shade tree in Koutal, a village in western Senegal where goats and chickens amble across the sandy lanes that separate one household from the next. At 11 in the morning, it is already blazing hot, though in a month’s time the rains and humidity of summer will make today’s weather seem sublime.

The men of Koutal could not plant the trees, Fall explains, because they were already occupied. Some worked in the nearby salt factory, transported there by beat-up vans that did not return them home until dark. Others had migrated to Dakar, the distant capital, in search of whatever jobs they could find.

But something needed to be done. Trees were disappearing in Koutal, and with them much else. “We didn’t even hear birds singing anymore,” says Fall.

None of the women beneath the shade tree are familiar with the term “climate change,” but all affirm that Koutal’s weather has grown more forbidding in recent years. Persistent drought has turned the soil dry and hard. It has also grown salty.

Although Koutal is located fifty miles from the Atlantic Ocean, two “arms” of the sea extend inland all the way to the village. The Senegalese government lacks precise data on how much the sea has risen, says Adama Kone, an agricultural extension agent, but soil tests indicate that seawater has penetrated the underground freshwater table, increasing the soil’s salinity and making it harder to grow crops.

“Taste it,” says one woman, pressing her index finger into the chalky white earth. “You will see we are telling the truth.”

Defying local stereotypes, the women of Koutal decided to fight for their village. With seedlings and technical expertise supplied by the Senegalese government and foreign donors, the women spent six years transforming 290 hectares of land from bare, crusted soil into a thriving agro-forestry reserve. There, they harvest timber to sell in the local markets while also growing millet and other crops to eat. Incomes and food production have risen substantially, and the women look to the future with a new sense of confidence.

“We are very proud that our children will benefit from this land,” says Adam Ndiaye, a hearty grandmother. “And they will know this work was done by women.”

* * *

Little did the women of Koutal know it, but by planting trees to save their village they were also building part of what advocates are calling the Great Green Wall of Africa. At the moment, this wall is more vision than reality. If it gets built, a Great Green Wall could be a game-changer for Africa—a solid advance in the fight against not only the emerging threat of climate change but the enduring scourges of poverty and hunger. Much depends, however, on which version of this wall gets built. Will it be, as some African heads of state have urged, a literal wall of trees stretching across the continent like a long and narrow plantation? Or will it be a more metaphorical wall that brings to scale such local successes as the achievements in Koutal?

These questions should be front and center when diplomats arrive in Durban, South Africa, this month for the next round of international climate negotiations. Two years ago, the Copenhagen climate negotiations ended in failure and recriminations, as the United States and other big polluter nations refused to limit their greenhouse gas emissions. But the success of grassroots initiatives like Koutal’s, and the prospect of establishing a Great Green Wall across Africa, suggest that there are practical solutions to the climate crisis, if one knows where to look.

And not a moment too soon. The horrific famine unfolding in the Horn of Africa is the latest reminder of what scientists have been saying for years: Africa is the continent that will suffer first and worst from the extra heat and drought that climate change will unleash over the coming decades. Of course, climate change is hardly the only reason that 750,000 people—half of them children—are projected to die in the Horn in the coming months, according to the United Nations; Somalia, the epicenter of the famine, has been plagued by civil war and a nonfunctioning government for years. But this famine was brought to a head by the worst drought to afflict Somalia in sixty years, a drought that has also brought widespread deprivation and hunger to neighboring Kenya and Ethiopia, two relatively peaceful and stable countries.

With Africa projected to get even hotter and drier in the years ahead, the need to prepare seems obvious. As does the need for fresh approaches. Rather than dispatching emergency food aid at the last minute—which lets Western governments and citizens feel good about themselves but does little to address the root causes of hunger—are there solutions that will help Africans avoid such dire circumstances in the first place?

That is one rationale for the Great Green Wall, an idea that in its present incarnation was proposed by Olusegun Obasanjo, the Nigerian president in 2005. Obasanjo’s vision was quite literal: he urged planting a fifteen-kilometer-wide (nine-mile) strip of trees across the width of Africa to prevent the Sahara Desert from expanding southward as climate change intensifies. Extending from Senegal in the west to Djibouti in the east, this wall of trees, it was said, would protect the densely populated Sahel region just south of the Sahara, where tens of millions of poor farmers and herders face the same hot, dry conditions plaguing Koutal.

African heads of state endorsed Obasanjo’s vision in 2005, and the idea gained international traction when British Prime Minister Tony Blair urged Western governments to place greater emphasis on fighting poverty in Africa and shed the paternalism that had soured past efforts. In the spirit of collaboration between partners, African and European leaders established the Africa-European Union Partnership on Climate Change, which in 2007 adopted the Great Green Wall of the Sahara and Sahel Initiative (the project’s official name) as its Priority Action No. 2.

“The Great Green Wall is an African-owned flagship initiative that will fight desertification, land degradation, loss of biodiversity and climate change while also tackling rural poverty and food insecurity,” says Abdoulaye Dia, executive secretary and CEO of the Pan-African Agency for the Great Green Wall.

But over time, the initial vision of the Great Green Wall has drawn criticism from scientists, nongovernmental organizations and others who argue that it embodies a top-down approach to development that fatally undervalues the importance of ecology and local people. Planting what amounts to a vast tree plantation across thousands of miles of African drylands is bound to fail, the critics warn. Young trees need care to survive: watering, pruning, protection from animals. That requires giving local people the incentive to provide such care, not to mention irrigation facilities for which—oops!—there often is no water supply.

“There was a great razzmatazz in the 1970s around the same basic idea, and it was a catastrophic failure,” says Dennis Garrity, director general of the World Agroforestry Centre, an international agricultural research institute known by its original acronym, ICRAF. “It sounded good to [African] heads of state, and [the foreign aid that funded it] was a great money maker for the forestry departments of African governments. It was, ‘You give us the money; we’ll plant all the trees you need.’ So the forestry departments went out and planted millions of trees. And of course, the vast majority of them soon died.”

Rather than a wall of trees, Garrity and other agricultural and development experts urge a more metaphorical Great Green Wall, one that champions a grassroots-driven, science-based approach to environmental restoration and sustainable development. Tree planting remains central to this vision, but it will be integrated with local food production and livelihoods, as in Koutal. The goal is to reverse land degradation as well as increase crop yields, rural incomes and food security. What’s more, this vision of the Great Green Wall includes a mosaic of projects throughout the Sahel, whether or not they line up neatly on a map to form a “wall” across the continent.

* * *

There are plenty of success stories a metaphorical Great Green Wall could draw upon. In its report “Sustainable Land Management in Practice,” the United Nations Food and Agriculture Organization (FAO) catalogs scores of them, including one example—the
regreening of millions of acres in the Sahel by farmers who grow (not plant) trees that regenerate naturally among their crops—that I detailed in these pages (see “Regreening Africa,” December 7, 2009).

Garrity and his ICRAF colleagues refer to these and other similar techniques as “evergreen agriculture,” which they define as “a fresh approach to achieving food security and environmental resilience…[by integrating] tree species into annual food crop systems.” Growing trees interspersed with crops is actually an old practice in Africa; it lost favor with the arrival of “modern” farming techniques from industrialized nations but is making a comeback. Dubbed “intercropping” by modern agronomists, it relies on trees and their leaves to maintain a green cover on cropland throughout the year; this, in turn, improves the soil’s structure, fertility and capacity to absorb water—all good things.

One tree that has contributed to extraordinary results is a species of acacia called Faidherbia albida. Indigenous to Africa, this tree takes nitrogen out of the air and “fixes” it in the tree’s roots, producing a protein-rich foliage that fertilizes the soil when the leaves fall. It’s like having “a fertilizer factory in the fields,” Mariko Majoni, a small farmer in Malawi, told Garrity. Faidherbia albida also has a unique growing cycle: its leaves shed in the early rainy season (in effect, springtime) and regrow when the dry season begins (autumn). Thus, the tree doesn’t compete with crops for light, nutrients or water. Numerous peer-reviewed studies have documented that yields of maize, the most widely grown crop in Africa, have improved when it is intercropped with Faidherbia albida, with increases often topping 100 percent.

But even an apparent miracle tree like Faidherbia albida is not the right answer everywhere; each local situation has its own characteristics. The women in Koutal, for example, also achieved yield increases of more than 100 percent but with a very different tool: peanut shells.

Peanut shells are very easy to come by in Koutal; the village sits at the edge of the vast peanut-growing plain of Senegal. That fact led Kone, the extension agent, to investigate whether peanuts’ chemical properties include a propensity to absorb salt. His initial research seemed encouraging, so with help from a microloan charging 10 percent interest, the women bought a machine that separates peanuts from their shells. The nuts they turned into peanut butter, which they fed their families or sold to neighbors. The shells they hauled to the fields and spread on the soil like fertilizer. Then they intercropped their corn and millet amid the young trees and bushes they were planting and nurturing.

The experiment proved out. In 2007 plots of land that had been covered with peanut shells yielded 575 kilograms of corn per hectare versus only 150 kilograms per hectare on land that had gone without shells—a nearly fourfold difference. Millet plots registered a two-and-a-half-fold difference. By 2009, as overall production doubled, the ratios were less dramatic (because less salt remained in the soil) but still substantial: corn yields were two and a half times larger on plots with shells; millet yields were one and a half times larger.

The increased yields vindicated the one man in Koutal who had been willing to assist the women. Louis Charles Ndao is a retired soldier who had visited the village while serving in the army in the 1970s. Returning in 1996, he was shocked by how degraded the area had become. He tried to persuade the village’s young men to join him in restoring it, he recalls, “but they had no interest.” So he sought to recruit women, though he was careful to respect village sensibilities. “I told the women, Don’t argue about this with your husband,” says Ndao, a sinewy 54-year-old. “If he says don’t come, then don’t come. Soon they will see the results and change their minds.”

Eventually, 190 women joined the campaign, drawn by the evidence that trees were putting more money in the participating women’s pockets. That is important, not only because women typically have lower incomes than men in Senegal (and in Africa as a whole) but also because women tend to spend their money more prudently.

“It is not safe to give money to a husband,” says Elizabeth Loupy, 38, who wears a turquoise head wrap above a wide, smiling face. “We invest money in the household. A husband will spend it elsewhere.”

Where? On drink?

All the women rush to answer at once, and the chatter is so dense the interpreter finds it hard to follow. Eventually one voice rises above and declares, as the other women nod in agreement, “He might take a second wife!”

* * *

The Great Green Wall is too good an idea to be allowed to fail, its supporters say. But can its stakeholders—African and European governments, development agencies, NGOs in Africa and Europe and, above all, the ordinary Africans in whose name the idea is advocated—come together around a shared vision and a means of achieving it?

That question hovered over a conference in June where the major players discussed next steps. The location, Dakar, was significant. Senegal’s aging president, Abdoulaye Wade, has long been an adamant supporter of the literal vision of the Great Green Wall. In fact, according to his former aide Dia (the executive secretary of the Pan-African Agency for the Great Green Wall), it was Wade who named the Great Green Wall when President Obasanjo outlined the idea to fellow heads of state in 2005. Now it appears those heads of state remain committed to Obasanjo’s literal vision, and none more so than Wade, whose government was represented at the Dakar conference by military fatigue–wearing officers of the Senegalese forestry department.

But the Western donors whose resources are needed to
finance any Great Green Wall—the EU, the Global Environmental Facility of the World Bank, the FAO—believe that the literal vision is doomed and should be replaced by something closer to the metaphorical vision described above. They are also concerned about organizational issues. Three African entities—the Pan-African Agency, the African Union and the Community of Sahel-Saharan States—have at various times claimed to be leading the Great Green Wall effort.

Moreover, the literal vision of the Great Green Wall turns out to rest on a basic scientific mistake. High-resolution satellite images captured by the US Geological Survey show that the Sahara Desert is not, in fact, advancing southward like a wave. Rather, says Gray Tappan of the USGS, “there are many specific places where poor land management has led to severe land degradation”—which suggests that the metaphorical vision is a superior response. As Tappan says, “These blotches of degraded land are what need targeting, not the entire border of the Sahara and the Sahel.”

Years of such push-back, especially coming from potential donors, appear to have caused African leaders to modify their visions of the Great Green Wall, if only rhetorically. Indeed, to hear Dia tell the tale, no one is more committed than he to ensuring local participation. “The Great Green Wall is for the local population, and it must be made by the local population,” he says. “That is our slogan.” But Dia, like other African civil servants who may want to do the right thing, has a dilemma. A geologist, he understands the scientific arguments against the literal vision of the Great Green Wall. But to embrace such arguments would alienate his patron, Wade, and other heads of state who have endorsed the opposite point of view.

In an interview, Dia denies that there is any divergence of vision about the future of the Great Green Wall, insisting that “we have one vision and one strategic approach.” Finessing differing perspectives, he adds, is an unavoidable requirement of politics: “At the beginning, the idea in [the heads of states’] minds was that the Great Green Wall must be a wall. If then the scientists had said, ‘No, a wall is not good,’ then the idea would not have gone ahead.”

Western donors apparently have made a similar calculus. “There is a shadow play going on [at this conference], which is often the case in international politics,” says Garrity of ICRAF. “We don’t try to fight the battle of redefining the Great Green Wall, because the heads of state have already defined it. We’ve decided instead to go along with political realities in order to create an operational momentum that will allow for successful implementation of truly valuable land-regenerating practices throughout the Sahel.” In other words, let the politicians call it what they like, but let the rest of us start working on the ground, doing what science and practical experience have shown is best, and the results should prove themselves.

Elegant it’s not, but this muddling-through approach just might work. The two contending visions of the Great Green Wall have come closer together over time, says Jozias Blok, the EU’s point person on the issue. “The focus on planting trees is much less than in the beginning,” he adds. “Instead, [the Great Green Wall] has been elaborated as a more integrated program of sustainable development that will address desertification, climate change, biodiversity and food security. One shouldn’t see the Great Green Wall as a single program but rather as a packet of different activities undertaken at the local level in each participating country.”

How much it will cost to create a Great Green Wall is not yet known. Countries will complete proposals for the Great Green Wall activities they want to pursue within their borders by the end of 2011; these will then be consolidated into regional plans by the spring of 2012 and submitted to donor agencies.

Which is where the ultimate decisions will be made, to the relief of critics of the literal vision. “My great hope is that the Global Environmental Facility [of the World Bank] will shoot down projects that are not scientifically valid,” confides Garrity. That seems likely. Monique Barbut, CEO of the GEF, is a keen advocate of the local participation in sustainable land management embodied by the metaphorical Great Green Wall. If such practices, along with the Evergreen Agriculture revolution ICRAF and others are advocating, can be scaled up across the continent, the Great Green Wall of Africa could become worthy of its name.

All sides agree that continuing with business as usual is unfeeling and unwise. Through no fault of their own, the people of the Sahel find themselves on the front lines of the fight against climate change. They are more than willing to help themselves, and there is much they can accomplish, as the remarkable feats in Koutal demonstrate. But the women of Koutal couldn’t have achieved what they did without the (very small) sums of aid they received from Western donor agencies to buy seedlings and pay for an agricultural extension agent. It’s fashionable nowadays to denigrate foreign aid programs as hopelessly misguided and self-interested, but the truth is more complicated. Years of effort and, yes, mistakes have left behind a fairly clear record of which practices work and which do not. A Great Green Wall of Africa can work, if the relevant parties so decide.

To wealthy Western taxpayers who ask why they should fund such efforts in faraway places, Garrity has a brisk reply: “I’d say, pay a few cents now in order not to pay billions later. The Sahel region is approaching the verge of social explosion because of food insecurity and a lack of economic opportunity, especially for the young. There is recruitment for Al Qaeda going on right now. We need to provide a better alternative.”

Mark HertsgaardTwitterMark Hertsgaard is the environment correspondent of The Nation and the executive director of the global media collaboration Covering Climate Now. His new book is Big Red’s Mercy:  The Shooting of Deborah Cotton and A Story of Race in America.


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