BBC: The government's chief scientist has said that there is already enough CO2 in the atmosphere for there to be more floods and droughts over the next 25 years.
Prof Sir John Beddington said there was a "need for urgency" in tackling climate change.
He said that the later governments left it, the harder it would be to combat.
Prof Beddington made his comments in the final week of his tenure as the government's chief scientific adviser.
"The [current] variation we are seeing in temperature...