World’s oceans hit hottest temperature on record in August

Key Points:

• The world’s oceans reached a record high average surface temperature of 21.1°C in August, marking the hottest level ever recorded and highlighting the escalating climate crisis.
• Over 90% of the heat trapped by carbon dioxide emissions from fossil fuels is absorbed by the oceans, which exacerbates sea level rise, intensifies extreme storms, and drives marine heatwaves that harm ecosystems and coastal communities.
• The current ocean heat spike is amplified by a developing El Niño event, expected to be the strongest in at least a century, already causing severe weather disruptions such as reduced monsoon rains in India and major wildfires in Indonesia and Australia.
• Scientists warn that warmer oceans reduce their capacity to absorb CO2, weakening a crucial natural buffer against global warming, and call for urgent fossil fuel emission cuts and enhanced protection of marine and coastal ecosystems to mitigate these impacts.
• Data from the European Union’s Copernicus Climate Change Service, which has tracked ocean temperatures since 1979, shows a tripling of marine heatwave days since the early 1990s, underscoring the growing stress on ocean systems worldwide.