The system of ocean currents that maintains our temperate weather could collapse. The Atlantic Meridional Overturning Circulation (AMOC), which brings heat from the Caribbean to the north Atlantic, could fail within 50 years. It has been weakening for decades due to global warming. The northern Atlantic is the only global region that is cooling. Experts now believe the chance of AMOC crossing the tipping point this century has increased from 10 to 50 per cent.

Meteorologists say the failure of AMOC would have "devastating and irreversible impacts, which will affect the entire world for centuries". It would negatively disrupt weather and the lives of hundreds of millions of people. Temperatures in the U.K. could become 15°C lower. Colder weather could "potentially threaten the viability of agriculture" in Europe. Tropical monsoons could shift south, causing drought, famine, climate refugees and geopolitical tensions.