A new study found that the North Atlantic Ocean has been absorbing Earth's excess heat, causing a global warming pause.
Global warming pause, or the global warming hiatus, is a slowdown on the increase of the average temperature of the planet and and seas. For many years, experts debated this idea, arguing there is no such thing as a "pause," but rather a "stop." Several studies also attempted to explain the cause of the global warming pause and pointed to different explanations: natural climate fluctuation due to cooling in the Pacific and increased sulphur emissions from volcanic activities.
Now, the new study is blaming it to the North Atlantic.
University of Washington researchers took Pacific Ocean temperature measurements to determine if it is really storing heat. However, the team was unable to find enough heat and tested the North Atlantic, using the Argo floats, which can track temperature and salt content up to 6,500 feet from the surface.
Study lead Xianyao Chen, an oceanographer, observed that the North Atlantic Ocean has been storing more heat than any other ocean in the world below 300 meters (about 1,000 feet) since 1999. This region trapped the excess heat because of its high salinity and cooler temperature, which causes the warm water from the equator to sink, along with the heat.
"It's important to distinguish between whether ocean heat storage is responsible for the hiatus versus not enough heat reaching the surface of the Earth," study co-author Ka-Kit Tung told LiveScience. "We did find enough heat stored in the North and South Atlantic Ocean that, if it remained on the surface, it would have resulted [in] rapid global warming."
Aside from the temperature data provided by the Argo floats, the researchers also looked at the Central England Temperature record for the past 350 years. The team saw a 70-year temperature-shift cycle, implying that after the cycle, global warming might resume within 35 years.
"We probably may have another 10 years, maybe shorter, as global warming itself is melting more ice and ice could flood the North Atlantic, but historically we are in the middle of the cycle," the researchers told BBC.
Further details of the study were published in the Aug. 22 issue of Science.
