London’s fogs may be about to make a comeback. Christine Corton, in the NYT:

In January, researchers at King’s College London announced that pollution levels on Oxford Street, in central London, had exceeded limits set for the entire year in just the first four days of 2015. Similarly alarming numbers have been recorded for other streets in the city — and yet the mayor, Boris Johnson, has delayed implementation of stricter air-quality measures until 2020.

What’s happening in London is being played out in cities worldwide, as efforts to curtail the onslaught of air pollution are stymied by short-term vested interests, with potentially disastrous results.

I just experienced a particular, particulate version of this hell first-hand in Delhi. For the last few days of my trip, a dense, thick haze – clearly not an innocuous fog – permeated the city and surrounding environs. On one trip back to our flat, all of my fellow taxi passengers complained of burning eyes and sore throats.

The closest PM monitor during that drive back — actually quite far from us — read over 250 µg/m3. That’s around 10x higher than a ‘bad’ day in the US. Moreover, we guessed that the levels we were experiencing were closer to 350 µg/m3. As a point of reference, the maximum mean hourly PM2.5 concentration in London since 2008 was approximately 30 µg/m3.

Corton points to a behavioral component to the historic London Fog episodes — a parallel I find particularly interesting:

There was a cultural component, too. The British were wedded to their open fires. Closed stoves, popular throughout much of Europe, especially in Germany, were shunned by Londoners. During World War I, Britons were exhorted, in the words of the famous song, to “keep the home fires burning.” Politicians were simply not willing to risk unpopularity by forcing Londoners to stop using coal and go over to gas or electric heating instead. In Britain today, in an echo of these earlier concerns, the government is cutting subsidies for onshore wind and solar farms, anxious not to offend voters in rural areas where such facilities would be built.

It took a disaster to force London to change direction. In 1952, a “great killer fog” lasted five days and killed an estimated 4,000 people. In a Britain trying to turn a corner after the death and destruction of the Blitz, this was unacceptable. A Clean Air Act was passed in 1956, forcing Londoners to burn smokeless fuel or switch to gas or electricity, power sources that had become much cheaper as these industries expanded.

Let’s hope that policy levers and momentum — not a disaster — can help transition away from solid fuels in India and beyond.