As you already know, China is facing a serious air pollution problem. The following set of pictures is night views taken from an airplane by my Chinese friend who recently visited Tokyo, Seoul, and Beijing. You cannot see the lights of Beijing city completely covered by the thick smog.
The following images are Beijing city that my friends took over a different period of time. When having serious air pollution, we cannot see even the buildings, behind the smog with high-level PM2.5.
The air Quality Index (AQI) has never been over 70 in Tokyo, Japan, in 2013 (Reference), but the following picture shows a day in Beijing when AQI marked over 500.
Causes of Air Pollution in China
Among many causes for air pollution in China, I hear most often followings:
- Over-dependent on cheap, inefficient, low-quality coal energy
- Increase of automobiles in city areas as result of economic development
You can also see the details on the following link, which is a self-financed documentary film, “Under the Dome”, made by Chai Jing, a former CCTV journalist.
Besides, China’s unique cultures often causes AQI to jump abruptly high.
The following images indicate the PM2.5 AQI during the spring festival (China’s New Year Day) in 2015 (left) and 2016 (right). China has the custom to enjoy fireworks during the spring festival, which causes temporary air pollution.
I heard that eco-friendly fireworks are getting popular these days.
Solution of Air Pollution
An economic trade-off exists between economic growth and solution of air pollution, so it might require a lot of time. An immediate potential solution might be as follows:
Pray for the wind
For people living in Beijing, strong wind is their best friend. It is not a fundamental solution at all, but the PM2.5 AQI dramatically drops after big gusts of wind, (but the implication is that the PM2.5 AQI in other cities might worsen due to this diffusion of smog).
Government regulations to extinguish root causes
One of the policies the Chinese government has adopted is the relocation of urban factories to the suburb (e.g. in Beijing’s case, factories are relocated to Hebei province). Besides, when China holds important events, they restrict the number of vehicles and the operation of factories to control the PM2.5 AQI.
For example, when Beijing was supposed to have APEC in 2014, they temporarily had closed government-related institutions and schools and restricted vehicles and factory operations one week in advance. Thanks to these efforts, Beijing could enjoy a beautiful blue sky, also known as APEC Blue (shown as the following image).
However, the PM2.5 AQI immediately resumed it previous state after the APEC term (See an image below), so APEC Blue was never a lasting solution.
Further, when Beijing held the “World Championships in Athletics” and “Victory over Japan Day” in 2015, the Chinese government regulated vehicles and factories just the same way in APEC. In winter 2015, Beijing’s city government issued its first red alert for air pollution, which caused them to restrict vehicles and closed schools
Reduce the quantity of regulation by technology
In search for lasting solutions, the Chinese government is improving technologies to improve the efficiency of coal energy (e.g. coal cleaning), develop alternative energy resources, let trucks use “Diesel particulate filter”, and introduce electric vehicles, etc. However, these technological measures might need a little more time.
(Extra) Seasonality and Geography
The level of the air pollution perhaps depends on seasons and geography.
Compared with the summer season, winter’s air pollution tends to be much worse. It’s because more heaters using coal energy are used in winter. However, many Chinese people go back to their hometown during the spring festival, so during this season, the air pollution tends to be reduced even in the winter season.
The air pollution in the northern part of China is much worse than the southern part. However, I personally think that the air pollution in the southern part is much more chronic.
The following images show the one-month transition of the PM2.5 AQI at the end of 2015 (Left: Beijing, Right: Shanghai).
The PM2.5 AQI in Beijing (north) rose sometimes over 500, but sometimes it dropped below 50. Meanwhile, the PM2.5 AQI in Shanghai (south) has neither risen over 300 PM2.5 AQI, nor has AQI ever dropped below 100. (A mere coincidence, perhaps?)
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