The Government's outgoing chief scientific advisor has called for urgent action to tackle global warming, warning climate change will bring greater extremes in weather.
Professor Sir John Beddington said the effects of climate change were already being felt in Britain.
"In a sense we have moved from the idea of global warming to the idea of climate change, and that is rather important - yes, indeed, temperatures are increasing, but the thing that is going to happen is that we are going to see much more variability in our weather", Sir John told BBC Breakfast.
"I think you only have to look at the last few years to see how that is actually starting to manifest itself even in the UK", he added.
He said there were "massive problems" in the world of food, water and energy security as the global population increases, all of which would be exacerbated by climate change.
Even if effective action was taken now on global warming, Sir John stressed there would be "significant" climate change over the next 20 to 25 years as results of past global emissions.