By Alison Hawkes
A fine yellow dust has gripped Beijing and parts of central and northern China, blown in from the Gobi Desert in a whirling cloud. Nothing, including China’s “Great Green Wall,” an ongoing project to develop a 2,800-mile belt of planted trees, could stop it.
On the ground, people went about their days draped in face masks, as Beijing reached a pollution index of 500 — the worst possible level — because of all the particulate matter in the air. From above the view is just as obscure, as this image captured by NASA’s Terra satellite on March 20 reveals little of the landscape below.
The sandstorms are expected during the springtime. Known as “Mongolian cyclones,” they draw up sand and dust particles and fed by strong, cold Siberian winds, spits it south some 500 miles (sometimes the dust travels as far as Arizona). Though the process is natural, the frequency and severity of sandstorms have been influenced by human factors.
Sandstorms were the worst during the 1950s and 60s communist revolution campaigns that raised farm and factory production, denuding the area of vegetation. These days the worsening sandstorms are attributed to deforestation, overgrazing, and a prolonged drought which are all causing the Gobi to grow on the order of one million acres of grassland a year.
Of course, climate change could be making this all worse. Unpredictable rainfall is causing vegetation, a buffer to the marching desert, to die off. Temperatures have risen 0.9 to as much as 3.6 degrees Fahrenheit since the 1970s, causing less rain to fall and creating desert conditions. As the desert expands, the cyclones have more dust and sand to draw from and from new areas. The Chinese Academy of Science estimated that about two dozen such sandstorms are occurring a year, a six fold increase in the past 50 years.
China’s sandstorm crisis demonstrates that it’s the worsening of natural processes and predilections that we should worried about, equally to reversals like melting sea ice. The Gobi Desert is already a harsh climate, and it could get a whole lot less habitable.