IT IS A long way from Kew Gardens to the southern edges of the Sahara desert. Yet scientists from the botanical garden are helping to plant a 5,000-mile wall of trees across Africa.
Experts believe the project, known as the Great Green Wall, will not only halt the degradation of land in the Sahel, which is pushing the region’s inhabitants deeper into poverty, but also stem the rising tide of Islamic militancy in the region.
Northeast Nigeria is being terrorised by Boko Haram insurgents who in April seized more than 200 schoolgirls, while al-Qaeda in the Islamic Maghreb, which is committed to overthrowing the Algerian government, continues to pose a significant threat in Mali despite the presence of French troops there.
Last week France announced the formation of a 3,000-strong counterterror force in Chad, while the Commons foreign affairs committee has warned that Islamic extremism in the Sahel, if left unchecked, “may well spread, with its effects being felt more widely across the world”.
Such groups feed on poverty. Farmland in the Sahel is diminishing fast. The region’s population is set to triple by 2050. As demands for food and water soar, climate change will make it far harder for its inhabitants to survive.
“If you look at where climate change will have its greatest effect it is in that belt that runs north and south of the equator, so the Sahel is part of that,” said Neil Morisetti, a retired admiral who served as William Hague’s special adviser on climate change.
“There are already food shortages, water issues, land issues. Climate change will only increase the risk of conflict in the region.”
Enter the Great Green Wall and Kew’s expert team of botanists and seedologists. If completed, the nine-mile-wide belt of forest will be the largest feat of horticulture in human history. Costing £70m, the wall will pass through 13 countries from Senegal’s Atlantic coast in the west to Djibouti’s Red Sea in the east.
The idea was originally conceived by the British explorer Richard St Barbe Baker during his 25,000-mile expedition to the Sahara in the 1950s. Baker believed that tree-planting could reclaim the desert.
Now, experts from Kew are working with villagers in Mali, Niger and Burkina Faso to plant the trees and herbaceous plants that will form a barrier against the Sahel’s advance south.
“It’s not every species that will grow in the Sahel,” said Moctar Sacande, 51, a seedologist who grew up in Burkina Faso before joining Kew 10 years ago. “But the main challenge is getting the villagers to maintain their involvement. We’re trying to show them that they don’t need to wait for four or five years to see the benefit.”
Sacande hopes that by the end of next year his team will be working in 120 villages, having planted more than 2m seedlings on 4,000 acres.
Kew’s expertise is recognised as essential to the success of the entire endeavour.
The secret lies in its efforts to conserve the world’s flora. So far, Kew scientists have tracked down and stored 10% of the world’s seeds. By 2020, Kew plans to hold a further 15% in its Millennium Seed Bank in Sussex — a quarter of the world’s flora.
The knowledge gleaned on the way has made Kew’s scientists among the world’s best at propagating extremely troublesome native species — some, for example, need smoke solutions or sulphuric acid to trigger their germination.
The villagers’ co-operation is key to the success of the project. To enlist their help, Sacande encourages them to cultivate faster-growing herbaceous grasses that can be used in cooking and also grazed by livestock.
There are also longer-term economic benefits. One type of acacia tree that Sacande helps plant produces the gum arabic used in chewing gum, stamps and in the manufacture of Coca-Cola, giving villagers an extra source of income.
The desert date’s fruit can be turned into jam, its leaves eaten by camels and its edible kernel used to make soap while the flowers from the cotton tree provide a base for sauces in west African cuisine.
It is an approach that other African nations have asked Kew to help them mimic in an attempt to stop the spread of the desert.
As the United Nations bluntly puts it: “The effects of desertification are increasingly felt globally as victims turn into refugees . . . or they turn to radicalisation, extremism or resource-driven wars for survival.”
Lake Chad, which provides a lifeline to 30m people in Chad, Cameroon, Niger and Nigeria, has shrunk to one-fifth of its original size over the past 50 years, destroying livelihoods in the process.
“Most of the guys who are into terrorism in that region used to be farmers, fishermen and herders who depended on the lakes,” said Uche Okpara, an expert on agricultural economics from Leeds University who recently returned from the lake.
He said the men became easy prey for insurgents. “These people are so angry with the government because it has done nothing to help them recover. So they take up arms.”
Sacande agrees but insists that it is not too late to reverse the trend. “When the land goes and the trees go, people become impoverished. They become poorer and poorer and find it harder to survive,” he said. “But they won’t be rushing to listen to the Islamists if you can show them there’s hope and that there’s a future for them and that it’s sustainable.”