Scientist calls for action on climate change
25 March 2013 Last updated at 10:04 GMT
The government's Chief Scientist, Professor Sir John Beddington, has urged world leaders to take urgent action to tackle climate change.
In his final interview in the role, he told BBC News there was already enough carbon dioxide in the earth's atmosphere to increase the frequency of floods and droughts over the next 25 years.
Professor Beddington said that, the later governments left it, the harder it would be to combat the problem.
Pallab Ghosh reports.