From Beijing to Bogotá, these numbers reveals the challenge the world’s cities face as they seek to reduce air pollution.
Face masks sold in Beijing on 8 December, double the usual number, after pollution levels prompted the first red alert in the Chinese capital, closing schools and businesses.
1 January 2016
The date Delhi will begin trialling a system limiting motorists to driving on alternate days based on their licence plate number (odd on one day, even the next). The concentration of PM2.5 particular matter (the small airborne particles that enter lungs and threaten health) has reached hazardous levels on some days in Delhi which, according to the World Health Organization, became the world’s dirtiest city in 2014.
13.2p a mile
The cost of the electric buses Bogotá has ordered to replace its fleet of 12,000 diesel vehicles over the next decade (an estimate that includes fuel costs, maintenance and repairs). Chinese company BVD is bidding to supply the Andino 12 buses which run on hydroelectric power, which means emissions per vehicle are virtually nil, and can drive 150 miles before the battery needs recharging. The Colombian capital’s mayor Gustavo Petro has launched the C40 group which aims to encourage the development of alternative fuel buses in cities across the world.
The cost, according to the US National Association of Manufacturers, of achieving the Environmental Protection Agency’s new allowable smog levels of 70 parts per billion by 2025. The NAM says this is the most expensive federal regulation ever issued. Smog is so bad in California, the EPA has given the state 12 extra years to meet its standard.
The year by which Paris mayor Anne Hidalgo would like to see no diesel-powered vehicles in the heart of the French capital. A car-free day across a third of the city in September reduced levels of nitrogen dioxide in some parts by 40 per cent. Hidalgo says she will also consider emergency traffic bans when the air is very polluted.