Diverting water is not enough. Fragile land such as Xinjiang needs care, not exploitation.
In the Commentary “Agriculture of the future” (Nature 428, 215–217; 2004), T. C. Tso argues that the Chinese government should use the country's three most important resources — people, land and water — to their best effect. We agree with this general principle. But we have three reservations regarding turning the Xinjiang region into the “California of China”.
First, the author gives the impression that Xinjiang is largely undeveloped and has “abundant resources”. Yet the area is home to 11 people per km2, far exceeding the international population-density standard for arid areas of 7 people per km2. Some 95% of the population live in oases totalling less than 60,000 km2. The population density in oases, at 292 inhabitants per km2, reaches that of many coastal cities. Far from being “undeveloped”, the area is densely populated and would have difficulty absorbing new migrants. Also, far from having “abundant resources”, it already experiences pressure on water sources. Large-scale agricultural expansion will require large amounts of water that are currently not available. Tso argues for the diversion of water from southern China, but this has the potential to create great ecological harm and international conflict, as discussed by A. Chen and C. Chen (Nature 429, 501; 200410.1038/429501a).
Second, the arid Xinjiang region is more ecologically fragile than Tso suggests. Desertification has increased as a direct result of overgrazing and unsustainable farming practices. During the past 50 years the area of desert has increased by 4,210 km2, at an average rate of 84.2 km2 per year, while lakes have decreased from 9,700 km2 to 4,748 km2. Many famous lakes have actually disappeared.
The area's main river, the Tarim, has been steadily dwindling for 30 years as a result of dam building and irrigation upstream. This in turn has reduced the growth of vegetation, including ancient poplar groves, that had long formed a barrier between two deserts. It is now possible that the Taklimakan desert and the Kumtag desert will merge. Each year the frequency and intensity of dust storms increase, and the effects are felt as far away as Beijing, Tianjin, Korea and Japan. If more people move into Xinjiang, the problem of desertification will inevitably be exacerbated.
Finally, the large-scale migration proposed by Tso could have serious cultural implications. The Xinjiang region is inhabited by the Uighur people, the fifth largest ethnic minority in China. Immigration by ethnic Han people could alter traditional ways of life followed by the Uighur.
Development in Xinjiang requires an adequate understanding of its environment and people. Turning it into the “California of China” is not a viable option.