28 mila fiumi scomparsi in Cina. Cosa è accaduto ?
Il governo e le fonti ufficiali cinesi danno varie spiegazioni, più o meno tutte riconducibili agli effetti del cambiamento climatico. Ma la realtà ci dice altro. Come racconta il servizio di
Angel Hsu and William Miao apparso il 29 aprile 2013 su The Atlantic
As recently as 20 years ago, there were an estimated 50,000 rivers in China, each covering a flow area of at least 60 square miles. But now, according to China’s First National Census of Water, more than 28,000 of these rivers are missing. To put this number into context, China’s lost rivers are almost equivalent, in terms of basin area, to the United States losing the entire Mississippi River.
Why have these rivers “vanished” from the maps and national records?
Official explanations from the Chinese government have attributed the significant reduction to statistical discrepancies, water and soil loss, and climate change.
“The disparity in numbers was caused mainly by inaccurate estimates in the past, as well as climate change and water and soil loss. Due to limited technology in the past, the previous figures were estimated using incomplete topographic maps dating back to the 1950s,” said Huang He, China’s Deputy Director of the Ministry of Water Resources, in an interview with the South China Morning Post.
While this explanation seems plausible, Chinese web users, an active and formidable force for raising environmental issues with the Chinese government, are not satisfied. One user named Yami Laoliu, writing on the popular Chinese social media platform Sina Weibo, voiced skepticism: “I am surprised to learn that 28,000 rivers have already disappeared in the map. Is it natural disaster? Or man-made mistake? I think both played a role, but it was mainly a man-made mistake.”
Peter Gleick, president of the Pacific Institute and a leading water expert agrees: “Climate change is a real threat to the world’s resources, and we already see evidence of impacts on water availability, quality, and extreme events. But the water challenges in China are far greater than just climate change,” he said.
Pinning the rivers’ disappearance on climate change is politically palatable right now, and the human origin of global warming is not controversial in China. But in an unusual twist, blaming climate change allows officials to absolve themselves of the poor management, governance, lack of groundwater extraction controls, and rapid development that are more likely culprits for the river’s disappearances.
“As China’s population and economy have rapidly grown, the country has experienced serious degradation of its water resources, including massive overuse and contamination,” Gleick said. “The ‘disappearance’ of major rivers and streams is far more likely to be directly connected to uncontrolled and unsustainable extraction of water for industry and agriculture, though climate change may play a greater role in the future.”
The past 30 years in which these rivers vanished have coincided with a phase of rapid industrialization and urban growth in China. From 1990 to 2000, urban areas expanded by more than 5,000 square miles, an area the size of Puerto Rico, and the expanding economy has correspondingly strained water and energy resources. In Yale University’s 2012 Environmental Performance Index, China is one of the worst performers (ranked 116 out of 132 countries) with respect to its performance on changes in water quantity due to consumption, including industrial, agricultural, and household uses.
Poor management of water resources has also exacerbated the situation. The main water resource law in China only requires permits for groundwater extractions for “large-scale” projects. The lack of specificity in this language has led to what Gleick says is substantial overdraft of groundwater throughout the country. Weak water governance also caused last September’s red water flow in to the Yangtze River, an occurrence that left even Chinese officials perplexed.
What about the statistical discrepancies that the government says could have factored in to the rivers’ disappearance? While some updates to river classification are plausible, cartography and mapping techniques have been very sophisticated in China for many years. One user on Sina Weibo tweeted an old map of waterways for Qingdao, showing abundant waterways in considerable detail. The maps are accurate and Qingdao’s rivers have not been wiped away by “improved surveying methods” — they have simply been converted into Qingdao’s sprawling roadways, said one of the city’s urban historians.
So why is the Chinese government blaming only climate change and statistical inaccuracies? Climate change is an easy and popular scapegoat and allows the government to save face by pinning the disappearance on natural causes rather than anthropogenic (and arguably preventable) ones.
However, as the Chinese online reaction demonstrates in this case and in recent air pollution events, the Chinese public may not be as willing to accept such a backseat approach to environmental management. Given the current state of the waterways and growing demand for water in China, authorities would be better served by thoroughly examining the root causes of the challenge and striving to be more transparent about both the certainties and the uncertainties surrounding the issue.