Climate change: Prepare for global temperature rise of 4C, warns top scientist | Environment | guardian.co.uk

"There is no doubt that we should aim to limit changes in the global mean surface temperature to 2C above pre-industrial," Watson, the chief scientific adviser to the Department for the Environment, Food and Rural Affairs, told the Guardian. "But given this is an ambitious target, and we don't know in detail how to limit greenhouse gas emissions to realise a 2 degree target, we should be prepared to adapt to 4C."

"I think that is a dangerous mindset to be in. Thinking through the implications of 4 degrees of warming shows that the impacts are so significant that the only real adaptation strategy is to avoid that at all cost because of the pain and suffering that is going to cost.

"There is no science on how we are going to adapt to 4 degrees warming. It is actually pretty alarming," he added.

Climate change: Prepare for global temperature rise of 4C, warns top scientist | Environment | guardian.co.uk