London Leads the EU in Car Pollution; Diesel Fuel Blamed

London has a dirty secret: Levels of the air pollutant nitrogen dioxide (NO), as measured by a monitoring station in the central city, are the highest in Europe. Concentrations of the compound are greater even than in Beijing, where smog alerts are common.

The European Union’s fight against climate change has favored diesel over gasoline, because diesel engines burn fuel more efficiently and emit less carbon dioxide (CO), the leading cause of global warming. But a byproduct of burning diesel is NO. “Successive governments knew more than 10 years ago that diesel was producing all these harmful pollutants, but they myopically plowed on with their anti-CO agenda,” says Simon Birkett, founder of Clean Air in London, a nonprofit. “It’s been a catastrophe for air pollution, and that’s not too strong a word.”