The world is on track to overshoot the targets of the Paris climate agreement and warm by 3C by the end of the century, a level that would disrupt life around the planet. A report from 91 scientists convened by the UN’s Intergovernmental Panel on Climate Change concluded the earth had warmed by 1C since pre-industrial times and was likely to heat up by a further 2C by the turn of the century, based on current policies. That would overshoot the targets of the Paris climate agreement in which more than 180 countries agreed to keep global warming “well below” 2C, without specifying what “well below” meant. “Every extra bit of warming matters,” said Hans-Otto Pörtner, a co-chair of the IPCC working group on climate impacts.

Warming of 1.5 degrees [Celsius] or higher increases the risk associated with long-lasting or irreversible changes.” The report was commissioned by the Paris signatories to help them understand the vastly different implications of 1.5C of warming — the target they agreed to move towards — and the 2C they committed to stay below.

While the report predicted they might miss even the upper range of the goal, it found that a 2C rise was far more dangerous than an increase that was half a degree Celsius lower. Coral reefs would disappear with 2C of warming, but if warming were limited to 1.5C, some would survive. The additional half a degree Celsius would expose an additional 420m humans to heatwaves, and cause 10m more people to face risks from rising sea levels, the report said.