New satellite data from the European Copernicus Climate Change Service shows the global average sea surface temperature in February was 21.06C, higher than the previous record of 20.98C set in August last year. Maps released by the organisation show huge areas of the world's oceans were much warmer than the long-term average. The US National Oceanic and Atmospheric Administration has warned sea temperatures are now so high that the global coral reefs face their fourth known mass bleaching event.