National Geographic has a recent article on a bold plan to stop the advancement of the Sahara desert.
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 of a plan to thwart the southward spread of the Sahara, Senegalese officials said earlier this month at the UN’s Copenhagen climate conference. The trees are meant “to stop the advancement of the desert,” Senegalese president and project leader Abdoulaye Wade told National Geographic News in Copenhagen. 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 (explore an interactive Sahara map). 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.
Having just finished reading Alan Weisman’s 2006 The World Without Us, I am reminded of Chapter 13 where he imagines ‘the world without war’ and writes of another type of ‘great wall’. In this chapter he describes what has happened within the Demilitarized Zone (DMZ) between South Korea and North Korea which has been ‘a world essentially without people since September 6, 1953’. It is now, somewhat ironically, critical habitat for many species including red-crowned cranes. He writes,
As the Korean naturalists watch, cameras and spotting scopes poised, over the bulrushes glides a dazzling white squadron, 11 fliers in perfect formation. And in perfect silence. These are living Korean national icons: red crowned cranes – the largest, and, next to whooping cranes, rarest on Earth. They’re accompanied by four smaller white-naped cranes, also endangered. Just in from China and Siberia, the DMZ is where most of them winter. If it didn’t exist, they probably wouldn’t either.
They touch down lightly, disturbing no buried hair-triggers. Revered in Asia as sacred portents of luck and peace, the red-crowned cranes are blissfully oblivious trespassers who’ve wandered into the incandescent tension of 2 million troops faced off across this accidental wildlife sanctuary in bunkers every few dozen metres, mortars poised.