Lawyer Alan Andrews, of environmental organisation ClientEarth, said an estimated 4, 300 Londoners now died each year as a result of air pollution (29, 000 UK-wide, according to the Department for the Environment, Food and Rural Affairs).

BBC: News, London

Rising pollution, global warming and shrinking fossil fuel reserves have focused world wide attention on how engines generate electrical and mechanical power.

CNN: Lab develops engine for the future