In 2023, the oceans experienced record-breaking marine heatwaves (MHWs), covering 96% of their surface and raising average temperatures by 1.3°C above normal. These heatwaves lasted 120 days, four times longer than in previous decades. Scientists link this to the ocean losing its role as a climate buffer—instead of absorbing excess heat, it has become a source of climate anomalies, causing coral bleaching, fish migration, and ecosystem disruption. A new study, based on data from ECCO2 and OISST satellites, showed that the causes of record warming vary by region, but reduced cloud cover, changes in ocean circulation, and El Niño’s influence were key factors everywhere.
The North Atlantic saw the longest MHW—525 days with anomalies up to +3°C. In the southwestern Pacific, heat penetrated to a depth of one kilometer and fueled the formation of the destructive Cyclone Gabrielle. In the tropical eastern Pacific, peak warming coincided with the onset of El Niño, when weakened trade winds reduced the upwelling of cold deep waters.
Scientists warn that continuing this trend could lead to the collapse of fisheries, intensified storms, and a shift to a new, less predictable climate state. To mitigate the impacts, we must not only cut emissions but also closely study regional warming mechanisms, as the ocean no longer serves its former protective role.
#space #science #educational #technology
