The report, structured around the UN Decade of Ocean Science for Sustainable Development (2021-2023), offers insights into ocean-related scientific activities describing the current and future state of the ocean. 

Key findings 

• Warming: Ocean is now warming at twice the rate it was twenty years ago.
  • Ocean temperatures have increased by an average of 1.45°C, with hotspots above 2°C in the Mediterranean, Tropical Atlantic Ocean and Southern Oceans. 
• Rising Seal level rise: Mostly due to accelerated ice mass loss from the Greenland and West Antarctica ice sheets, and to a lesser degree from accelerated ocean warming.
• Acidification: Ocean absorbs around 25% of annual anthropogenic CO2. This process reduces seawater pH (ocean acidification). 
  • Ocean acidification would increase by more than 100% by the end of the century
• Deoxygenation: Ocean oxygen content is decreasing, resulting in worsening hypoxia. 
  • However, it is unclear whether deoxygenation is accelerating in response to ocean heat content increase. 
• Coastal blue carbon ecosystems: Mangroves, seagrasses and tidal marshes provide refuge against a warmer, more acidic ocean, and are an important store of carbon. 
  • However, their protection is not guaranteed and 20–35% have been lost since 1970.