While fog and smog are certainly nothing new to London, The Great Smog of 1952 is an incredible event that brought the city to a near standstill from December 5 to December 9. The event left approximately 4,000 people dead, killed cows as they grazed in nearby fields, and caused significant problems for those with breathing disorders.
The cause of the smog was the culmination of multiple events. Foremost, a weather pattern that the UK’s national weather service, Met Office, refers to as an anticyclone moved into the area. Accordingly, an anticyclone-
“…pushes air downwards, warming it as it descends. This creates an inversion, where air close to the ground is cooler than the air higher above it.”
Such an inversion traps air born contaminants, such as smoke, that would otherwise rise and dissipate into the atmosphere. Which brings us to a second effect that led to The Great Smog: Cold weather and the need for heat.
Temperatures in the area during this time were extremely cold with substantial snowfall. To keep warm, area residents burned large quantities of coal. Thick black smoke from these fires belched from the chimneys of nearly every residence in the city.
Instead of this smoke rising and dispersing, the anticyclone trapped it along with other contaminants the poured into the air from factory chimneys located throughout London. Making matters worse, the weather pattern also brought in pollution from other industrial areas across the continent.
All of this led to a smog so thick that it diminished visibility to a few yards. In some places the smog was so thick that people were unable to actually see their feet. During the nighttime hours it became impossible for people to find their way through even the most familiar of neighborhoods.
The Met Office states that over the course of The Great Smog, the following amounts of contaminants were released into the air on each day–
- 1,000 tons of smoke particles
- 2,000 tons of carbon dioxide
- 140 tons of hydrochloric acid
- 14 tons of fluorine compounds
- In addition, and perhaps most dangerously, 370 tons of sulfur dioxide were converted into 800 tons of sulfuric acid
Naturally, The Great Smog led to a number of laws regulating emission from private homes and industries. Because of these laws, a repeat the The Great Smog has been avoided and Londoners enjoy living in one of the greatest cities on earth.
Here are some photos from various sources…
(Click on a picture to enlarge it)
Check out this three-part documentary on The Great Smog