The report is the second in a series of three that comprise the best summary of global scientific evidence around climate change and its impacts.

Written and approved by hundreds of scientists and signed off by 195 governments, the report represents the starkest warning yet about the effects of climate change and the world’s preparedness.

Over nine million climate-related deaths per year are projected by the end of the century, under a high emissions scenario, the report said.

Hans-Otto Pörtner, a leading author, said: “Any further delay in concerted global action will miss a brief and rapidly closing window to secure a liveable future.”

High temperatures have hit Europe hard during recent heatwave events, with 2020’s high summer temperatures contributing to 2,556 deaths in England.

Heat is particularly deadly for older people and those with heart and respiratory health problems, and can be exacerbated by a housing stock ill-adapted to stay cool in hot temperatures.

Current global temperatures are thought to be around 1.1C higher than the pre-industrial average. The Paris climate agreement committed nations to making efforts to limit warming to 1.5C, a pledge that was renewed at the last year’s Cop26 summit.

Current estimates based on government policies suggest the world is on track for warming of around 2.7C by 2100.

Each fraction of extra warming makes extreme weather including heavy rainfall, heatwaves and drought worse, and limits the world’s ability to adapt, the report warned.