There is already enough carbon dioxide in the atmosphere to lead to more floods and droughts over the next 25 years, the government’s chief scientist has said.

Professor Sir John Beddington said there was a “need for urgency” in tackling climate change and that the effects must be combatted now – the later governments left it, the harder it would be to adapt.

Speaking to BBC News in his last week as the government’s chief scientific adviser, he said:

"The [current] variation we are seeing in temperature or rainfall is double the rate of the average. That suggests that we are going to have more droughts, we are going to have more floods, we are going to have more sea surges and we are going to have more storms.

"These are the sort of changes that are going to affect us in quite a short timescale."

Beddington said the issue of climate change is being clouded because Earth’s climate system reacts slowly to changes and so there are long delays in carbon dioxide level rises in the atmosphere. He said the next 20 or 30 years are “going to be determined by what's up [CO₂] there now."

Governments have agreed to try to keep the rise in average global temperatures to below 2C. However, floods and droughts are an immediate threat to the globe and there have been numerous calls for the world to adapt to extreme weather events now.