Air pollution has become the world's greatest environmental health risk, and science is only beginning to reveal its wide-ranging effects. Globally, 19,000 people die each day from air pollution, killing more than HIV/AIDS, tuberculosis, malaria and car accidents combined. What happened to the air we breathe? Sustainability journalist Tim Smedley has travelled the world to try and find the answer, visiting cities at the forefront of the fight against air pollution, including Delhi, Beijing, London and Paris. With insights from the scientists and politicians leading the battle against it, and people whose lives have been affected by it, Clearing the Air tells the full story of air pollution for the first time: what it is, which pollutants are harmful, where they come from and – most importantly – what we can do about them. Air pollution is a problem that can be solved. The stories uncovered on this journey show us how. Clearing the Air is essential reading for anyone who cares about the air they breathe. And this much becomes clear: in the fight against air pollution, we all have a part to play. The fightback has begun.