3 min readAug 26, 2026 06:10 AM IST First published on: Aug 26, 2026 at 06:10 AM ISTThe world’s oceans are usually at their warmest in March and April. In March 2024, global sea-surface temperature simmered to a record 21.09 degrees Celsius. That high was surpassed last week. On August 22, a rapidly intensifying El Niño and global warming combined to spike marine temperature to 21.1 degrees Celsius. The new record, along with the upending of the ocean calendar, is a warning: Global heating is moving climate into unfamiliar territory. The last two months’ data indicates that what happened on August 22 was not an anomaly. June’s average sea surface temperature across the extra-polar oceans was the highest ever recorded for that month. The July record was also surpassed. By July 31, the oceans had heated to 0.04 degrees below the previous all-time high.The oceans are among the greatest buffers against climate change. According to the IPCC and NASA, oceans absorbed more than 90 per cent of the excess heat generated by global warming and helped to delay its most catastrophic consequences. But this sequestering influence has come at a cost. Warming places stress on marine ecosystems, disrupts food webs. It also affects the oceans’ capacity to regulate weather. A heatwave has overwhelmed Europe this summer, several parts of India experienced floods even though the monsoon was erratic, and unseasonal snowfall disrupted life in South America. Ocean warming also contributes to sea-level rise. By the end of 2025, global average sea level was about 11 centimetres higher than in January 1993.AdvertisementEvery climate record strengthens the case for mitigation — cutting fossil-fuel consumption, accelerating the transition to clean energy and reducing greenhouse-gas emissions. That imperative remains important. However, even as emission reduction plans become more ambitious, adaptation to weather vagaries — which has historically played second fiddle to mitigation in climate policy — needs to be on a stronger footing. Even if emissions were brought down sharply, the consequences of past warming will take years to disappear. India, with a coastline of more than 10,000 km, needs to invest in protecting people who live along the shores, restoring natural barriers against raging waters, improving drainage in urban centres and developing climate-informed agriculture and water management systems. The message from the warming oceans is clear: Improving climate resilience cannot be postponed.