If China cleans up its smog, we all benefit: Bob McDonald

Stifling smog conditions in Beijing this week closed schools and factories and forced people to wear masks in the streets. If China cleans up its air as London did, after the Great Fog of 1952, we get a boost for climate change as well.

China's pollution problems have echoes of the London fog that hit England in 1952

Stifling smog conditions in Beijing and other major cities in China this week forced people to wear masks in the streets. (Andy Wong/Associated Press)

Stifling smog conditions in Beijing and other major cities in China this week closed schools and factories and forced people to wear masks in the streets. It's a condition eerily similar to the famous London fog that struck England in 1952.

Both are the result of burning coal, and if China cleans up its air as London did, we will get a boost in reducing climate change as well.

Dec. 5, 1952 began as a clear, cold winter morning in London. But that soon changed to the worst smog-choked period in the city's history, where visibility was reduced to near zero for four days, crippling transportation and causing more than 4,000 deaths. The pollution was so deadly that even cows were choked to death in their fields.

London is famous for its fog and mists, but when the Industrial Revolution introduced coal burning, the density of the fogs increased, while their chemistry became deadly. On that fateful morning, people were burning extra coal in their homes to keep warm, while coal-fired generating stations and factories continued spewing their unfiltered black smoke into the air.

A temperature inversion, caused by a layer of high-altitude warm air over the city, trapped the smoke at ground level, while fog began to form over the cold ground.

Fine smoke particles act as nuclei for water vapour, as it condenses into water droplets. The more particles there are, the thicker the fog becomes. Adding to the problem was the fact that England at the time burned low-grade coal, containing higher amounts of sulphur and other impurities. Emissions from the burning combined with the water in the fog to form sulphuric acid, hydrochloric acid and fluorine compounds, which can all do damage to lungs. 

What became known as "The Big Smoke" was not the first poisonous fog to hit London, but it was the most deadly, prompting the government to impose a series of environmental regulations that ultimately led to the much cleaner air London enjoys today.

It's an example of how we don't really deal with environmental problems until they hit us in the face.

Seeing solutions

The photo of Tiananmen Square on the left was taken on Dec. 1, 2015. At right, the same scene two days later, after a shift in the weather temporarily cleared the skies. (Wang Zhao/AFP/Getty)

The situation in China is almost identical, as the country is building new coal-fired power plants every day to keep up with the country's rapidly growing industrial sector. Meanwhile, a more affluent society is adding millions of cars to the roads every year.

So, whenever a temperature inversion comes along, visibility drops in the cities and health advisories are sent out.

Now that the smog and its ill health effects are in the face of the Chinese, the government is imposing tighter restrictions on carbon emissions, as well as bringing in a new environmental protection law and a new air pollution law. 

Even before this crisis, they were investing in more alternative energy technologies. These actions not only benefit the people of China, but there is a spinoff effect for the rest of the world as well.

Thanks to the lower emissions coming out of China, there was the encouraging announcement this week that the growth of carbon emissions worldwide has plateaued over the last two years.

Scientists are hoping this is the beginning of a trend that might lead to an overall reduction of carbon emissions, which will avert our trend towards the dreaded 2ºC tipping point in the climate.

The lessons of L.A. smog

Both of these examples of governments imposing stricter environmental regulations came about because the problem became visible to people in the streets. We saw similar action in California in the 1970s, when tough emission standards were imposed on cars after years of smoggy summers in Los Angeles.

It seems that when it comes to environmental stewardship, foresight is not the primary driving force. Climate scientists have been warning about the dangers of a warmer planet for decades. But despite images of calving glaciers and polar bears stranded on small ice floes, and after a string of international meetings, not enough action has taken place to halt the steady rise in global temperatures.

Does that mean we will have to wait until the effects of climate change are in our face before we do something about it?

The lessons from the past have shown that waiting too long costs lives.

How many more lives will be lost through droughts, severe storms or wildfires before it becomes obvious that something is really happening? Let's not let the climate lessons of the past get lost in a fog.


Bob McDonald is the host of CBC Radio's award-winning weekly science program, Quirks & Quarks. He is also a science commentator for CBC News Network and CBC-TV's The National. He has received 12 honorary degrees and is an Officer of the Order of Canada.