A red alert was issued by Beijing authorities late on Monday due to the thick smog blanketing the city and it will last until midday on Thursday. During this period, schools and kindergartens are advised to close, and companies and public institutions can choose flexible working. Cars are allowed to drive only on alternate days depending on their license plate numbers.

This is the first time that Beijing or any big city in China has raised the air pollution alert to the highest level with rigid precautionary measures taken. It carries a symbolic significance.

The concept of PM2.5 monitoring was only introduced to China in recent years. Monitoring equipment at the US Embassy in Beijing reported serious air pollution in the city in October 2011 and the result ignited uproar after it was posted on Weibo. People argued about the severity of the pollution, over-detailed indicators of PM2.5 levels and possible intervention of the US Embassy into China's environmental protection.

Ever since, Chinese people's opinions about PM2.5 have changed constantly. The index has not only become a standard to monitor air quality in China, but has prompted the evolution of the concept of environmental protection in Chinese society. Delicate changes have happened to the country's views of criticism and external factors. The shift from the controversy in 2011 to Monday's red alert can be called a revolution of ideas.  The country now faces its problems head-on and respects the public's appeals and demands. Generally it has adapted itself to confronting reality instead of covering up thorny issues. This last may be the most important.

The public grievances and discussions about the smog put the government under huge pressure to clean up the air. But people are more clearly aware that the smog, caused by all, needs concerted efforts from the whole of society to address it.

It is unlikely that the smog can be eliminated in the short term, but the red alert placated people that the government has attached utmost importance to it, which is largely considered as a core guarantee to solve problems.

The smog issue prompts the public and government to have in-depth exchanges and hence more mutual understanding and trust. They have highly consistent interests in eliminating the smog and more common interests than divergences in the hard choice between development and the environment.

The spat over the smog shows a key capability of Chinese society to break through barriers and reach consensus. This can boost our confidence in dealing with other complicated disputes in the future.

A climate in which both the government and the public respect the facts has been in the making. We must understand that no one can be kept out of the public campaign against smog.