Nature: A United Nations panel has proposed the first global greenhouse-gas emissions standard for aircraft.
The draft rule, released by the International Civil Aviation Organization (ICAO) on 8 February, applies to most commercial and business aircraft, including designs already in production. It would require minimal changes to aviation design over the next 12 years, and many environmentalists say that the proposal is inadequate to combat climate change.
The plan -- which would take full effect in...