Humanity has missed its chance of keeping global warming below 1.5C and it will take “heroic efforts” to stay below 2C this century, the scientist leading the global effort to understand climate change has warned.

Jim Skea, chairman of the Intergovernmental Panel on Climate Change (IPCC), said a failure to sufficiently curb carbon emissions had left the world on track to warm by 3C by 2100. This average masks variations between land and sea, with western Europe and the UK facing even greater warming – perhaps as much as 5C by the end of the century.

“We are potentially headed towards 3C of global warming by 2100, if we carry on with the policies we have at the moment,” said Skea…

The Met Office has tried to project the UK impacts. By 2070, it says, winters will be up to 4.5C warmer but 30pc wetter, meaning more flooding. Summer will be up to 6C warmer, with frequent droughts and surging numbers of heat-related deaths.

Skea said: “It’s very clear climate change is no longer decades in the future. It’s very obvious it’s happening now, so we need to adapt.”

“One of the biggest risks in many regions will come from the combination of heat and humidity.

“It will just be difficult to live and to work outside. In some parts of the world, that will be really a showstopper for some kinds of economic activity.”

Europe faces some of the biggest challenges. Other scientists have predicted Scotland becoming a centre for wineries, that Poland will struggle to grow staple crops such as potatoes and Italy might no longer be able to cultivate durum wheat – used to make pasta.

Skea warned of deserts appearing in southern Europe. He said: “The whole of Europe is vulnerable and especially the Mediterranean. We are already seeing desertification taking place, not only in North Africa, but some of the southern margins of Europe, like Greece, Portugal and Turkey.”