According to a 2013 report by the United Nations Convention to Combat Desertification (UNCCD), desertification, land degradation, and droughts have accelerated globally during the twentieth and twenty-first centuries, particularly in arid, semi-arid, and dry sub-humid areas. Throughout the past 40 years, the Earth has lost a third of its arable land to erosion and degradation.
In a big move to address the problem, in 1978, the Chinese government implemented the Three-North Shelterbelt Project, a national ecological engineering effort that called for the planting of millions of trees along the 2,800-mile border of northern China’s encroaching desert, while increasing the world’s forest by 10 percent. Also known as the “Great Green Wall,” the project’s end date isn’t until 2050; so far, more than 66 billion trees have been planted.
“With the Great Green Wall, people are planting lots of trees in big ceremonies to stem desertification, but then later no one takes care of them, and they die,” says Jennifer L. Turner, director of the China Environment Forum at the D.C.-based Woodrow Wilson Center.
Additionally, afforestation can exceed the land’s carrying capacity, dooming the trees to an eventual death without constant human intervention.
“People crowded into the natural sand dunes and the Gobi to plant trees, which have caused a rapid decrease in soil moisture and the groundwater table,” Xue says. “Actually, it will cause desertification [in some regions].”