Source: Global Times [00:27 August 03 2010]
Jiang Gaoming

Editor's Note:  It's been a restless summer for anyone living along the Yangtze River. Flooding has overwhelmed reservoirs, and flood-control facilities along the river are facing their biggest test since 1998. It's said that the flood is a once-in-a-century event caused by climate anomalies, but Jiang Gaoming (Jiang), chief researcher at the Chinese Academy of Sciences' Institute of Botany, holds a different viewpoint. He asserts that a seemingly natural calamity is actually a man-made disaster. Global Times (GT) reporter Wang Yuan talked to Jiang on the source of the flooding.

GT:  Why do you think the flooding in the Yangtze River this year is more of a man-made disaster than a natural one?

Jiang: Many experts attribute this year's flood to climate anomalies. It sounds right, since the precipitation in Yangtze River valley this year was extremely high, and global warming might have contributed to the high precipitation. However, high precipitation alone does not necessarily lead to such a devastating flood. It's not that simple. Devastating floods occurred in the past with normal frequency, but in recent decades the term like "once in a century" has been repeated over and over again to describe different floods. People still remember the severe flooding along the Yangtze River in 1998, and this year an even worse one has occurred. I think it's unnatural, and we should rethink the cause of the floods.

Actually, a more important factor than climate change is that the Yangtze River's capacity for precipitation is decreasing. This change is mainly man-made.

The vegetation in areas on the middle and lower reaches of the Yangtze River has been greatly damaged on account of replacing natural forests with tree plantations. For example, in Yunnan Province, natural tropical forests were replaced by fast-growing eucalyptus forests, and in Hubei Province, natural forests were burned out and man-made forests were established to produce paper. The water conservation ability of man-made forests, which have a seriously limited range of species, is much weaker than that of natural forests. Diversity leads to stability. Moreover, geographical environments along the Yangtze River have been changed. For example, Hubei Province was once called "the province of lakes," as its name reflects. In flood seasons, its numerous lakes served as irreplaceable flood storage channels.

However, now a large amount of lakes have disappeared due to land reclamation, boosting the pressure in the main channel. There have been hundreds of hydroelectric power stations, big and small, built along the whole of the Yangtze River. They also contribute a lot to frequent flooding, as they obstruct the flow of water.

These man-made factors have reduced the Yangtze River's capacity to endure high rainfalls. Consequently, the same amount of rain now leads to worse floods than in the past, and so we see "once-in-a-century" floods every few years.

GT: Why do experts automatically attribute flooding to climate change?

Jiang: High precipitation is indeed a direct cause of the floods, and global warming and climate change could lead to abnormal precipitation, so it's natural that people would put the floods down to climate anomalies.But at the same time, potential man-made factors are sorely neglected.Most people, including many meteorologists, lack a sense of self-examination. When natural disasters happen, their initial reaction is to put all the blame on outside causes.It does not just happen with floods, but also happens with many other natural disasters, like sandstorms and droughts. For example, every year winds blow over the Mongolian Plateau, but why are the sandstorms getting more serious year by year? It's because of water loss and soil erosion in the plateau caused by human disturbance. Sometimes, after the event, some would start to rethink the role of humanity in causing these disasters, but usually even such self-examination is not profound enough to strengthen public awareness and take actual and effective remedies. For example, after the severe flooding along the Yangtze River in 1998, preventing the destruction of vegetation and soil and water loss in the regions along the Yangtze River was
put on the agenda.  At that time, a number of relevant policies were set, but they produced very little effect.

GT: In China, the implementation of environmental policies is usually unsatisfactory. Many local governments insist on operating some projects that violate environmental laws. Do local governments seek advice from relevant experts, like you, when they make decisions on whether a project should be run?

Jiang: Yes, in many cases they do. I myself have been consulted in some cases. But the problem is whether experts' advices is considered seriously - it's a pity that sometimes they are not.Last year, the Chongqing government planned to establish the Xiaonanhai Hydroelectric Power Station on the Yangtze River, which would be located in the only national fish reserve in the Yangtze River and could lead to the extinction of a great number of rare fish species.Many environmentalists and experts dedicated themselves to halting the project. At last the project was stopped, but I'm afraid that it wasn't because of experts' objections. Actually, it was the central government's intervention that stopped it.

Economic profits and GDP are often the initial considerations of local governments and many interest groups, like large pulp corporations and power stations, while protecting the ecological environment cannot bring them visible profits in the short term. Usually some local governments will consider environmental problems seriously only if the central government interferes.We should ascertain where the responsibility lies, and those who neglect their environmental protection duties should be penalized.

Otherwise, actions that damage the environment will continue unabated.Maybe this year we can stop Hubei Province from burning natural forests and planting pulpwood forests, but without mandatory accountability, we cannot make sure the same project would not happen again.

GT: Since local governments are obsessed with profit, is there any way to put a price on environmental protection?

Jiang: Western scientists have introduced some measures to provide intuitive evaluation, which is called the valuation of ecosystem services. This can put a value on all kinds of ecosystem. For example, it can calculate how much oxygen a forest releases. But such methods might not be persuasive enough when providing advices to those local governments, which only emphasize the economy and GDP growth. The economic profits calculated are abstract, and could not be transferred into cash. However, those eco-unfriendly projects, like pulpwood forests, can bring local governments tangible profits. So it cannot be measured in terms of money. Making mandatory laws and regulations is the only effective way. Policymakers and lawmakers need to realize that a good natural environment can also bring economic benefit.Local residents can profit from it, as at least people's health and agricultural production would be guaranteed. It can also bolster the development of the tourism sector. More importantly, good environment could work up support for national security.  Each time there are serious natural calamities, like flood and draught, soldiers have to be sent to provide disaster relief. It seems that it has been our army' major task.  A better environment and less natural disasters could allow the army to spare more resources to improve their military abilities.

转载本文请联系原作者获取授权，同时请注明本文来自蒋高明科学网博客。
链接地址：https://blog.sciencenet.cn/blog-475-349698.html

上一篇：长江水灾：“怨天”更要“尤人”
下一篇：农民为何重新喜欢有机肥？