https://phys.org/news/2019-01-oceans-faster-previously-thought.html

Ocean heating is critical marker of climate change because an estimated 93 percent of the excess solar energy trapped by greenhouse gases accumulates in the world's oceans. And, unlike surface temperatures, ocean temperatures are not affected by year-to-year variations caused by climate events like El Nino or volcanic eruptions.

The new analysis, published Jan. 11 in Science, shows that trends in ocean heat content match those predicted by leading climate change models, and that overall ocean warming is accelerating.