In March 2014 sustainability journalist Tim Smedley helped his wife and newborn baby out of St Mary’s Hospital in Paddington, unaware that he was taking them along one of the most polluted roads, in one of Europe’s most polluted cities, in the middle of a month-long air pollution episode that would cause 600 deaths and 1,570 emergency hospital admissions in London alone. Tim tells the full story of air pollution: what it is, which pollutants are harmful, where they come from and, most importantly, what we can do about them. Amidst terrifying statistics Tim uncovers the hope that remains for the planet.

Shortlisted for the Royal Society book prize.