Ocean temperatures set to break all-time record: what’s next?

Key Points:

• The world's oceans are nearing an all-time heat record due to human-caused climate change and a strengthening El Niño event, threatening marine ecosystems and reducing the ocean's capacity to absorb carbon dioxide.
• Sea surface temperatures have already broken monthly records in June and July 2024, with current temperatures just below the March 2024 record, and are expected to surpass it soon as El Niño intensifies.
• The anomalous warmth is widespread, affecting the tropical Pacific, northern Pacific and Atlantic, and the Mediterranean Sea, with climate change making these high temperatures dozens of times more likely.
• This prolonged ocean heat wave has sparked debate about whether Earth's climate sensitivity to human emissions is higher than previously estimated, as the ocean's behavior over the past four years has been unusual.
• Elevated ocean temperatures pose significant risks to fisheries, coastal communities, and especially coral reefs, which face severe stress and potential collapse under these extreme conditions.