mexico City, the most polluted city on the planet, is considering radical methods to clean up its act. Travellers to Mexico's capital city often fail to see it from air as it is usually shrouded by smog throughout the year. This has cost the city dearly, with many of its people suffering from pollution-related diseases. And after decades of living under a perpetual haze, the city authorities are planning to control its weather in an attempt to clean the city up. They are testing an antenna system designed to bring about changes in the local rainfall and wind patterns. The sceptics, however, are not very impressed.

The antenna ionises the atmosphere, creating nuclei on which water vapour can condense. Physicists Lev Pokhmelnykh of the Mexican firm Electrificaci