The world 4C warmer

With catastrophic rises in sea levels drowning island nations such as the Maldives, floods and droughts making hundreds of millions homeless and exposing them to starvation and disease, this map shows how the world would be affected by the effects of a 4C rise in global temperature.

On the eve of the climate change talks in Copenhagen, the bleak scenario shown here – based on the latest scientific predictions from the Met Office Hadley Centre – remains a terrifying possibility. Developed nations – those chiefly responsible for emissions – and developing countries which will bear the brunt of climate change are showing little sign of agreement on cutting emissions or on who will pay for poor countries to develop low-carbon economies. Hopes are fading of a deal that could limit a global temperature rise to C, which in itself would see tens of millions displaced.

Professor Bob Watson, Defra's chief scientific adviser and former head of the Intergovernmental Panel on Climate Change, said: "We should start to be prepared at least to think about what are the implications to adapting to 4C. I think it's going to be very, very difficult to meet a target anywhere close to C."

If high emissions continue unchecked, the 4C scenario shown here could become a reality by 2060, according to the Met Office.