Urban air pollution: smog in Chinese cities

Satellite image of China showing extent of the air pollution in December 2013, Source: NASA

PM 2.5 Concentrations

While monitoring of overall levels of pollution have caused alarm, the levels of PM 2.5 concentrations as a component of this air pollution have caused particular concerns.

PM 2.5 is particulate matter that has the diameter of 2.5µm (micro metres) which is around 1/30 the width of a human hair. This means it is small enough to enter into the human lungs and even into the blood system, and therefore has serious health implications.

The WHO has set a maximum safe limit of exposure to these particles to 25 per cubic metre of air.

Many Chinese cities regularly experiences levels of PM2.5 and PM10 well above 200 per cubic metre (Beijing has even reached 800).

Until recently data on PM2.5 was not released by the Chinese government, readings could only be based on those published by the US embassy however the policy was changed due to pressure via social media.

You can monitor the Beijing levels via twitter or Shanghai.
 
You can also view pollution levels for London.

Causes of the pollution problem

The Environmental Performance Index (produced by Yale and Columbia universities) ranks countries according to air quality (calculated form a number of indicators).
 
According to their 2014 Environmental Performance Index China ranks overall 118 out of 178 countries. This is based on indicators for air quality, water quality, sanitation, forest and fishery conservation and climate control policies. However, it was the worst ranked country (178 out of 178) for PM2.5 concentrations.

There are a number of reasons why the pollution problem has developed in China:

• The use of coal in China has increased ten-fold since 1960s. Rapid growth in population, industrialisation and urbanisation has meant that demand for and use of, the amount of fossil fuels used has increased dramatically.

• Much of the air pollution is blamed on coal-fired power plants. 

• Growth in population, and in particular a rising number of people who can afford the use of a car has meant there has been a rapid rise in the number of vehicles in cities.

• In many northern Chinese cities coal fired heating systems are still used, which means additional pollution is produced.

• In some cities the landscape makes the problem worse. For example Beijing is surrounded by hills which can result in pollution remaining trapped, particularly if there is little wind.

According to the US Energy Information Administration coal supplies the majority of energy consumption in China as much as 70% (while oil is 19%, hydroelectric is 6%, natural gas is 4%, nuclear is 1% and other renewables around 0.3%). However, China has set targets to raise their energy consumption from non-fossil fuel sources by 2015.

Costs and Solutions

The Chinese Academy for Environmental Planning has estimated that it will cost ¥1.7 trillion Yuan (around £180 billion) between 2013 and 2017 to be able to significantly reduce the pollution in the skies. The Chinese government have recognised the need to address the pollution problems. From March 2014, no further oil refining, steel, cement and thermal power plants will be permitted in Beijing. In a five-year action plan, the Chinese government stated it would try to reduce the level of airborne particulates (PM2 and PM10) by at least 10% in major Chinese cities by 2017.
 
The Chinese government has already invested ¥1.7 trillion Yuan (£180billion) to clean up power stations and traffic fumes. Officials in China are confident that green technology will help overcome the country’s air pollution problem and that just like other cities they can progress from polluted to cleaner cities.

The BBC conducted an interview with a senior environmental official:

"You can see those big cities like in London in Britain, Los Angeles in America and Tokyo in Japan, they all had huge air problems in the past – for example, London was nicknamed Smog city – which was caused by fast industrialisation…We have already moved fast to cope with this issue. So we are very confident about reaching a good level of air quality and changing our capital into a Green Beijing in the future" ( BBC News, 2014).

A growing global issue

There are also studies which suggest that the pollutants are drifting back across the Pacific Ocean to the extent that a quarter of the sulphate pollution in the Western US originates from China as seen in the map produced by the University of California, Irvine. Black carbon is particulate matter (also known as PM 2.5) and is produced by incomplete combustion of fossil fuels, biofuels and biomass.