Most people do not think of China as a desert nation – and yet it is among the world's largest. A staggering third of China’s land area, 2.5 million square kilometres, is useless sand. Incredibly, only 7 % of Chinese land feeds a fifth of the world’s population. But this makes China particularly vulnerable. China’s soil erosion is the most serious of any country in the world, and an estimated 400 million people are now being moved in order to secure more arable land for farming. Plans are already underway to move these people into the urban centres of China by 2030.