The Pacific Ocean covers about one-third of the Earth’s surface. Much of it has been cooling in this era of “global” warming.

New research indicates there has been “cooling of the Pacific sector on decadal timescales during 1940-2020,” including robust cooling reaching -0.4°C per decade from 2005-2019 (even “exceeding -0.9°C per decade during 2005-2010”).

“…observations find a significant cooling of the South Pacific Ocean during 1979-2013”

“…cooling of the Pacific sector on decadal timescales during 1940-2020 in the reanalysis data”

“Sea surface temperature has been decreasing in the southwest Pacific Ocean since 1979, where the cooling has reached -0.9°C per decade during 2005-2010.”

“The warming trend in the Indian sector reaches 0.2°C per decade, and the cooling trend in the Pacific sector reaches -0.4°C per decade during 2005-2019.”

Pacific Ocean cooling is not just confined to the near surface, but also to the deep ocean.

“We further suggest that the Pacific cooling is robust from the surface to the deep, and can even reach the intermediate ocean up to 1500 m rather than being limited to the mixed layer.”

“The cooling trend is also significant in the deep 1000 m, reaching -0.2°C per decade.”

Image Source: Ni et al., 2026