Scientists warn: The Pacific is heating rapidly, raising the risk of record temperatures in 2027

The Pacific is heating at levels that have put scientists on alert. The World Meteorological Organization’s latest seasonal forecast gives El Niño a probability close to 100% of lasting until February 2027, while models point to further strengthening in the months ahead.

In the Niño 3.4 region, used to measure El Niño’s intensity, sea-surface temperatures from May through July averaged 1.5 degrees Celsius above normal. The gap reached 2 degrees in July. From late July to mid-August, weekly anomalies ranged between 2.2 and 2.6 degrees.

The heat is even more striking below the surface. In some parts of the Pacific, subsurface temperatures in July and early August stood as much as 8 degrees above normal. WMO models project average Niño 3.4 anomalies of up to 3.6 degrees between September and November, with the increase potentially peaking in November and December. Those figures have strengthened assessments that the current El Niño could become one of the strongest on record.

El Niño occurs naturally, usually every two to seven years. During a normal cycle, trade winds push warm surface water westward across the Pacific and help cold, nutrient-rich water rise along the coast of South America. When the winds weaken, warm water moves toward the central and eastern Pacific, while the upwelling of cold water declines.

That shift can alter atmospheric circulation, rainfall and temperatures far beyond the Pacific. Scientists say the event is more dangerous because it is unfolding in an ocean already significantly warmed by human-caused climate change. Warmer seas and reduced nutrient-rich upwelling can lower phytoplankton levels, affecting the food chain from small fish to large predators, seabirds and marine mammals. Coral reefs face another serious threat because prolonged heat can damage corals. Some marine species may also have to move northward or into deeper waters in search of suitable temperatures and food.