Between 1979 and 2020, the average amount of sea ice extent, the area of ocean where there is at least some ice, in the Arctic has decreased by a surface area roughly equal to the size of Greenland.
The findings can be found in the fifth edition of the Copernicus Ocean State Report, published last week in the Journal of Operational Oceanography. This year's report draws on analysis by over 120 scientific experts from more than 30 European institutions. The annual publication presents a comprehensive summary on the current state of Earth's oceans.
"Climate change, pollution, and overexploitation have placed unprecedented pressures on the ocean, requiring the urgent need for sustainable measures for governance, adaptation and management in order to secure the various life support roles the ocean offers for human well-being," Karina von Schuckmann, who chaired the report, said in a news release.
"Scientifically sound knowledge derived from high-quality ocean products and delivered by ocean services is critical to stimulate transformative change. Considering the ocean as a fundamental factor in the Earth system and embracing the multidimensional and interconnected nature of the ocean is the bedrock for a sustainable future."
The report touches on a number of key changes and trends in the world's oceans.
For example, sea levels rose at an average rate of 3.1 millimetres per year from January 1993 to May 2020. The Baltic Sea rose the most, at a rate of 4.5 millimetres per year.
During that same period, ocean temperatures increased an average of 0.015 degrees Celsius per year. At the top of the list was the Black Sea, which increased in temperature by 0.071 degrees Celsius per year.
Arctic Ocean warming on its own is estimated to contribute to nearly four per cent of global ocean warming.
Speaking of the Arctic, a near 90 per cent reduction of average sea ice thickness has been witnessed in the Barents Sea, northwest of Russia, according to the report.
Extreme changes between cold spells and marine heatwaves in the North Sea, which is nestled between the U.K., Norway, Denmark, Germany and the Netherlands, as well as parts of Belgium and France, has been linked to reported changes in catches of sole, European lobster, sea bass, red mullet and edible crabs.
The report also noted four consecutive record flooding events in Venice, Italy, in November 2019, along with higher-than-average wave heights in the southern Mediterranean Sea.