In Hong Kong, where pollution is so bad that the government frequently advises the elderly and very young to stay indoors, there is a bittersweet joke about why millions of visitors come from the Chinese mainland to visit. Ah, say the wags, they come to enjoy the environment.
In fact, Hong Kong's pollution levels are lower than in most parts of China, where less than one percent of the largest cities managed to meet World Health Organization's air quality standards according to a 2012 Asian Development Bank report.
The statistics of environmental degradation in China are remorselessly depressing: 90 percent of underground water in cities and 70 percent of rivers are polluted, indeed a third of these rivers are so toxic that they endanger health; seven of the world's 10 most polluted cities are in China and smog contributes to around a million premature deaths each year. China is the world's largest emitter of carbon dioxide and choking smog in cities reaches levels that make it hazardous to go outside.
This level of environmental degradation is not really news, although even Chinese citizens would be alarmed if the state-controlled media permitted the publication of articles that pulled these pollution threats together. Yet the news is getting out and social media is playing an enormous role in conveying this information. Deng Fei, an environmental activist, for example, has some four million followers on Weibo, China's hybrid version of Twitter and Facebook. In February, the Chinese Communist Party mouthpiece, People's Daily reported an opinion poll that cited citizens' environmental concerns as one of their most pressing issues.
This growing awareness has sparked a wave of protests, most of it local and uncoordinated but nevertheless - and this is very unusual in China - protesters are managing to achieve a number of objectives in a country where the end point of most protests is jail or exile.
The latest official State of the Environment report recorded 712 cases of "abrupt environmental incidents" in 2013, up 31 percent from the previous year. Many of these "incidents" are in fact protests, and the level of protest in the current year is, if anything, on the up. Yang Chaofei, the vice-chairman of the Chinese Society for Environmental Sciences, told members of the powerful Standing Committee of the National People's Congress that environmental protests have been growing 29 percent annually from 1966 to 2011.
Most of the earlier protests were in rural areas; now they have moved to the towns and are harder to ignore.
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In May, a protest against the building of what was billed as Asia's largest waste incinerator plant in Zhejiang province, in eastern China, resulted in a back down when the government declared it would not proceed with construction without "the support of the people". An earlier protest in the Songjiang district of China's biggest city, Shanghai, against the building of a massive lithium battery factory, also resulted in the plans being put on hold. In Ningbo, another major eastern city, protesters managed to block the construction of an $8.9bn petrochemical plant in 2012.
These protests can be dismissed as part of a not-in-my-backyard syndrome. But they are also powerful reminders of public awareness over the environmental impact of manufacturing activity, and the profound consequences of pollution.
However, by far the biggest cause of pollution is coal burning, much of it derived from electricity generation.
The government is vividly aware of this problem, and has now become one of the biggest spenders on renewable energy production. $290bn was committed to these projects in the five years to 2015 but this is dwarfed by even greater investment in nuclear energy - which carries risks of a different kind - yet is far more environmentally friendly than coal power generation.
The government led by President Xi Jinping has shown itself to be far more proactive than that of his predecessor, and makes every effort to demonstrate its understanding of environmental concerns. Last year Premier Li Keqiang pledged "even greater resolve" to tackle the pollution crisis. This is not merely a matter of pacifying public opinion but stems from an awareness of the cost of pollution which World Bank economists put at $242bn per year, based on 2010 figures; clearly the cost has risen since then.
'War on pollution'
In December 2013, the government issued its first nationwide blueprint for tackling climate change, accompanied by a list of objectives to be achieved by 2020. This was followed in January by instructions to 15,000 factories requiring them to report real-time air emission and water-discharge data. Li is now speaking about a "war on pollution".
In April, China's parliament finally got round to legislation providing extensive powers to punish, control and supervise polluters. This comes after a two-and-a-half decade hiatus since the last environmental protection law was enacted.
The length of time it has taken to introduce this legislation is a reflection of the intense battle within China's ruling circles between those who adhere to the idea of economic growth at all costs - and those who believe that these costs are becoming too high.
As ever, internal battles within the Chinese leadership are only spoken of obliquely and it is never quite clear how these discussions are going. Environmentalists in China say that passing laws is one thing, implementing them is quite another. Their scepticism over the leadership's true commitment to tackling these problems will only be assuaged once evidence emerges of decisive action against polluters on a par with, say, the current crackdown on corruption.
Tacit toleration of environmental protests is highly unusual in a nation that regards all protest as a threat to state security. The fact that some of these protests have achieved their objectives is even more significant. The big questions now are whether the current protest trend will continue to escalate - and how the state will respond.
Stephen Vines is a Hong Kong-based journalist, broadcaster and author of several books. He was a founding editor and publisher of three newspapers and magazines in the Asian region. In London, he worked as an editor for The Observer, and several other publications.
The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policy.