Urban pollution - returning as a major issueIn the year 1900, the reign of Queen Victoria was nearing its end. For a century the coal burned, the smoke billowed, and smog would lie over cities like a smothering blanket.
For 100 years cities grew, pollution grew, and thousands died of the resulting diseases.
Public outrage grew, calls for regulations, controls, restrictions, and solutions grew, yet well into the 20th Century the blight of urban pollution persisted.
As cities around the world came to embrace and comfortably settle into the Industrial Revolution, the problem grew internationally.
Nobody quite knew what to do. How could the problem be solved without complete disruption to the transport of goods, freight, people and the whole system which cities had come to rely upon?
I am talking, of course, about horses.
In London this problem peaked with the Great Horse Manure Crisis of 1894. Flies and pests were attracted, they spread disease, and worse, in New York dead horses were often left for many days before removal. It was only in 1912 that automobiles began to outnumber horses in New York.
At the time the automobile was seen as a great solution to the problems of the day - cars don't make manure or die.
The year 1900 also saw Lord Kelvin announce to the British Society that "there is nothing new to be discovered" (of course he was referring more narrowly, and famously incorrectly, to physics) and now we know that the fossil fuels we burn in cars contribute to a new kind of urban pollution.
And it looks even worse.
It's becoming increasingly well documented that pollution particles enter the brain and may play a significant role in increasing the risk of Alzheimer's disease. It's estimated that 50,000 people per year die prematurely from air pollution in the UK. In Europe air pollution is estimated to cause 467,000 premature deaths every year.
Climate change has been the greatest focus of research, funding, and political and public attention, but perhaps this is set to change. In today's world, where grand forecasts are made using complicated, poorly-understood, statistical analysis by increasingly distrusted "experts", public health is a much more relatable and immediate problem for most people.
In London where parents have been warned against taking their babies outside because of dangerous levels of air pollution, in a Paris where public transport has been temporarily made free to battle against air pollution, in a Delhi where the government had to declare a public emergency because of air pollution, and where a ban on diesel cars by 2025 has been called in four major world cities, a very compelling public case seems to be mounting for serious change.
Just as technology replaced the horse, so it will replace the internal combustion engine. There is still plenty left to improve upon and discover - poor Lord Kelvin!