A record-breaking 23 zettajoules of heat was sunk into the world\u2019s seas last year, leaving ocean waters hotter, higher and less hospitable, a report has found.<\/p>\n
The explosive addition of thermal energy, which was almost 40 times greater than all the energy humanity used that year, comes amid far-reaching changes to the deep water bodies fundamental to life on Earth.<\/p>\n
Sea levels have risen by about 3.8mm per year since 1999, and at a faster rate of 4.2mm per year between 2012 and 2025, according to the 10th edition of the Copernicus ocean state report. It found the global ocean has become 17% more acidic in the last 40 years.<\/p>\n
Oceans have absorbed about one-third of the carbon dioxide that humanity has spewed and about 90% of the extra heat that greenhouse gas pollution has trapped in the Earth\u2019s system.<\/p>\n
\u201cThe ocean is transforming before our eyes,\u201d said Pierre Bahurel, director general of Mercator Ocean International, which published the report. \u201cWarming, rising seas and ecosystem degradation are interconnected signs of significant and long-term change.\u201d<\/p>\n
In Europe, which is heating twice as fast<\/a> as the global average, the Mediterranean and Black Seas have been plagued by record-breaking marine heatwaves \u2013 with elevated temperatures that persist deep below the surface \u2013 and bouts of extreme heat that have lasted more than a month, the scientists found.<\/p>\n A Mediterranean swimmer in mid-January: the entire sea has warmed by .32C per decade. Photograph: Hassan Ammar\/AP<\/p>\n The scientists found a clear acceleration of sea level rise in the western Mediterranean, even as the eastern part showed uneven gains. The entire sea has warmed by 0.32C per decade, the report found, driving up marine heatwaves, particularly in the last few years. A joule, the unit used to measure heat, is the amount of electricity required to run a one watt device for one second; a zettajoule is a billion trillion joules.<\/p>\n