This is going to be interesting for many cities, but I can speak to the case of Madrid. The Partido Popular government fixed the pollution problem by moving th

This is going to be interesting for many cities, but I can speak to the case of Madrid. The Partido Popular government fixed the pollution problem by moving the sensors out of busy streets and into big parks that happen to be within the city limits[1,2]. The historical continuity of measurements has been lost, but Google will now provide data with more continuity. Or at least I hope it is provided. [1] http://elpais.com/diario/2009/05/18/madrid/1242645857_850215.html http://elpais.com/diario/2009/05/18/madrid/1242645857_850215... [2] http://www.ft.com/cms/s/0/022cf59c-3091-11e0-9de3-00144feabdc0.html http://www.ft.com/cms/s/0/022cf59c-3091-11e0-9de3-00144feabd...