‘Headed off the charts’: world’s ocean surface temperature hits record high

Scientists warn of more marine heatwaves, leading to increased risk of extreme weather

The temperature of the world's ocean surface has hit an all-time high since satellite records began, leading to marine heatwaves around the globe, according to US government data.

Climate scientists said preliminary data from the National Oceanic and Atmospheric Administration (Noaa) showed the average temperature at the ocean's surface has been at 21.1C since the start of April - beating the previous high of 21C set in 2016.