Global heating will drive billions of people out of the “climate niche” in which humanity has flourished for millennia, a study has estimated, exposing them to unprecedented temperatures and extreme weather.

The world is on track for 2.7C of heating with current action plans and this would mean 2 billion people experiencing average annual temperatures above 29C by 2030, a level at which very few communities have lived in the past.

Up to 1 billion people could choose to migrate to cooler places, the scientists said, although those areas remaining within the climate niche would still experience more frequent heatwaves and droughts.

However, urgent action to lower carbon emissions and keep global temperature rise to 1.5C would cut the number of people pushed outside the climate niche by 80%, to 400 million.

The analysis is the first of its kind and is able to treat every citizen equally, unlike previous economic assessments of the damage […]