Unprecedented Heatwave Sets New Record in the Pacific Ocean

Sun Oct 19 2025 16:06:46 GMT+0300 (Eastern European Summer Time)

A recent marine heatwave has caused ocean temperatures in the north Pacific to rise to record levels, sparking concerns among climate scientists about its implications both locally and globally.

This year, the north Pacific has experienced its warmest summer on record, with sea temperatures exceeding the previous highs. Climate scientists are investigating the unusual longevity and intensity of this heatwave, referred to as the 'warm blob', which could have effects on weather patterns across the globe, including colder winters for the UK. Potential contributing factors are under scrutiny, including changes in shipping fuel and broader climate impacts.

The waters of the north Pacific have had their warmest summer on record, according to BBC analysis of a mysterious marine heatwave that has confounded climate scientists.

Sea surface temperatures between July and September were more than 0.25C above the previous high of 2022 - a significant increase across an area ten times the size of the Mediterranean.

While climate change is known to make marine heatwaves more likely, scientists are struggling to explain why the north Pacific has been so hot for so long.

Some researchers believe this excessive heat could lead to a colder start to winter in the UK.

There's definitely something unusual going on in the north Pacific, said Zeke Hausfather, a climate scientist at Berkeley Earth.

The BBC's analysis, which used data from the European Copernicus climate service, shows that not only has the region been warming quickly, but 2025 stands out as markedly higher than recent years.

The increase in sea temperatures is reportedly so significant that these values had a less than 1% chance of occurring based on climate models.

Dr. Hausfather suggested natural variability and weaker-than-usual winds might allow more heat to remain at the surface, but acknowledged that natural variability alone cannot explain the drastic changes.

There's speculation that changes in shipping fuel regulations might be contributing to the warming, as the reduction of sulphur dioxide emissions from ships diminishes natural cooling effects linked to aerosols.

The implications of this heatwave are already being felt, contributing to extreme weather patterns in Asia and the US. For instance, California has experienced intense thunderstorms fueled by the warmer ocean waters.

The phenomenon may also have repercussions for the UK and Europe, potentially leading to colder winter conditions as weather patterns are influenced by the heat in the north Pacific.

This situation is further complicated by the emergence of La Niña conditions to the south, which traditionally are associated with colder starts to winter in the UK.