Agence France-Presse: London’s mayor came out Monday against plans to build a third runway at the city’s main airport at Heathrow, saying it should be scrapped for environmental reasons. Ken Livingstone, who is running for re-election in May, said he opposed expansion at Heathrow and elsewhere in southeast England to protect "generations who will come after us." "Rather than more runways and plane journeys, we must cut carbon emissions by using energy more efficiently," …