BBC: What's the worst kind of noise? Lots of it spread over a day, week a month or short, sharp peaks with long gaps in between? How do you know if a traffic jam in Hounslow is because of the airport a few miles away? How big will biofuels be in the future?
The government's got a lot of complex questions to answer if it decides to expand London's Heathrow Airport. The Airports Commission's report has kicked the process off, but it can't decide policies. Ultimately the government must referee the whole...