‘Headed off the charts’: world’s ocean surface temperature hits record high – The Guardian – Climate Reanalyzer
Scientists warn of more marine heatwaves, leading to increased risk of extreme weather.
A global map using data from the National Oceanic and Atmospheric Administration showing areas in orange and red where temperatures have been above the long-term average. Photograph: University Of Maine.
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.
“The current trajectory looks like it’s headed off the charts, smashing previous records,” said Prof Matthew England, a climate scientist at the University of New South Wales.
Three years of La Niña conditions across the vast tropical Pacific have helped suppress temperatures and dampened the effect of rising greenhouse gas emissions.
But scientists said heat was now rising to the ocean surface, pointing to a potential El Niño pattern in the tropical Pacific later this year that can increase the risk of extreme weather conditions and further challenge global heat records.
Dr Mike McPhaden, a senior research scientist at Noaa, said: “The recent ‘triple dip’ La Niña has come to an end. This prolonged period of cold was tamping down global mean surface temperatures despite the rise of greenhouse gases in the atmosphere.
“Now that it’s over, we are likely seeing the climate change signal coming through loud and clear.”
La Niña periods – characterised by cooling in the central and eastern tropical Pacific and stronger trade winds – have a cooling influence on global temperatures. During El Niño periods, the ocean temperatures in those regions are warmer than usual and global temperatures are pushed up.
According to the Noaa data, the second-hottest globally averaged ocean temperatures coincided with El Niño that ran from 2014 to 2016.