Over the past year, climate change has driven the world’s oceans to record-breaking temperatures nearly every single day, according to data from the EU’s Copernicus Climate Service. These record highs in sea surface temperature have severe implications for marine life, coral reefs, and weather patterns worldwide.
The temperature records are primarily attributed to human-induced climate change, exacerbated by the natural weather event El Niño, which tends to warm ocean surfaces in the Pacific. The effects have been drastic, with more than 50 days exceeding the previous temperature highs for that time of year by the largest margin in the satellite era. From March 2023, sea surface temperatures rose steadily, reaching an unprecedented average of 21.09°C in February and March 2024.
The impact on marine ecosystems has been severe, leading to widespread coral bleaching and affecting species like the emperor penguin. As oceans absorb around a quarter of carbon dioxide emissions and 90% of excess heat from climate change, these temperature spikes are a stark indication that the oceans are struggling to cope. This rapid warming affects coral reefs, leading to mass bleaching, and influences marine biodiversity, with some species vanishing from coastal regions due to the heat.
El Niño, which began in June 2023, has contributed to these extreme conditions, but other ocean basins, like the Atlantic, have also seen unusual temperature patterns. This phenomenon, which typically causes warmer water to surface in the Pacific, leads to increased global temperatures, but it doesn’t entirely explain the warming in other regions, leaving scientists to explore other contributing factors.
The warmer seas have various consequences, including the possibility of more intense tropical storms and hurricanes, with warmer waters providing extra energy. Additionally, long-term effects like ice-sheet melting and deep-ocean warming could lead to continued sea-level rise in the coming centuries.
Researchers emphasize that while these findings are concerning, they shouldn’t discourage efforts to curb emissions. By reducing greenhouse gas emissions, it’s possible to slow the rate of ocean warming and mitigate the most severe impacts. Despite the profound changes already observed, there is hope that collective action can help address the root causes of climate change and its effects on the world’s oceans.
