The air pollution in Hong Kong has gotten so bad that tourism officials have put up a banner displaying what the skyline looks like on a clear day.

This week, Hong Kong’s Air Pollution Index’ reached ‘Very High’ in Central and Western District, Causeway Bay and Mongkok, with ‘very high’ levels of toxic ozone and nitrogen dioxide recorded at roadside monitoring stations.

Smog is a big problem in China were it was recently reported life expectancy has been by five-and-a-half years for those living in its polluted north.
Researchers estimate that the half-billion people who lived there in the 1990s will live an average of 5 and a half years less than their southern counterparts because they breathed dirtier air from coal burning.

China itself made the comparison possible: for decades, a now-discontinued government policy provided free coal for heating, but only in the colder north.

Earlier this year, air quality in Beijing reached ‘worst on record’ following a sand storm which led to pollution in the city rising to 30 to 45 times above recommended safety levels.