(This article was a winner of the National Magazine Award Silver Medal for Photojournalism & Photo Essays. In October 2008, Benoit Aquin was awarded the Prix Pictet, an award given to projects that highlight sustainability issues.)

Walrus Online Exclusive: More photos from “The Chinese Dust Bowl” can be seen here.The k43-t69 train that follows China’s great northern steppes and the legendary Silk Road could be dubbed “the desertification train.” Travelling from east to west, from Beijing to Urumqi, it cuts through 3,343 kilometres of dusty grasslands, dried-up riverbeds, threatened oases, and deserts both ancient and new. A few hours after the train leaves Beijing, a lunar black mountain range welcomes passengers into a vast arid landscape.

Deserts cover 18 percent of China today. Of those, 78 percent are natural, while 22 percent were created by humans. Almost all of them lie along the k43-t69’s route through the provinces of Inner Mongolia, Ningxia, Gansu, and finally Xinjiang, at the edge of Central Asia.

Lulled by the rhythmic clang of metal wheels on rails, for two days passengers can watch a dreamscape of steppes and deserts go by. But the view also reveals one of the greatest environmental disasters of our time: the Chinese Dust Bowl, probably the largest conversion of productive land into sand anywhere in the world.

To date, Chinese farmers and herders have transformed about 400,000 square kilometres of cropland and verdant prairie into new deserts. The shepherds have overgrazed the steppes, allowing their sheep and goats to chew the grass all the way down to its roots. The farmers, for their part, have over-exploited the arable land by opening fragile grasslands to cultivation and over-pumping rivers and aquifers in the oases bordering the ancient deserts. The area of desert thus created is equivalent to more than half the farmland in Canada.

The soil, once it is barren, is swept up by the wind into dust storms, battering the capital, Beijing, and then moving on to Korea and Japan. The most massive of the yellow clouds of dust make their way across the Pacific and reach North America. The loss of precious topsoil for Chinese agriculture ends up polluting both China’s cities and countries halfway around the world.

The North American “dust bowl” of the 1930s forced three million farmers to abandon their land in the Midwest and the Canadian prairies. But the Chinese exodus could reach well into the tens of millions. Governmental relocation programs for ecological refugees are already in full swing.

From their choice vantage point at a window seat in the k43-t69’s upscale restaurant, train passengers can witness another equally spectacular sight: everywhere on the horizon, scores of men on old three-wheeler trucks wield shovels, tree seedlings, and shrubs. All over the desert, unnaturally straight rows of trees now stand against the wind. The k43-t69 also overlooks the greatest environmental restoration effort in history.

Since 1978, Chinese forestry engineers have been supervising the planting of the Great Green Wall. Some 4,500 kilometres in length, the tree barrier is intended, when completed in several decades, to prevent desertification by protecting the fragile land from wind.

Another project of equally immense proportions is the South-to-North Water Transfer. It aims to redirect to the north, by the year 2050 via a network of canals, about 50 billion cubic metres of water per year from the rivers of southern and central China. The project will obliterate heritage sites and engulf villages and towns.