The blog below written by Green Party candidate for the Mayor of London, Siân Berry. It's part of a series of blogs by candidates for London Mayor. We've also featured blogs by Caroline Pidgeon (Liberal Democrat), Zac Goldsmith (Conservative) and Sadiq Khan (Labour).
London's air quality is one of the worst in Europe. Add your name to the thousands of people demanding clean air now.
The power of good ideas – Green action on air pollution