Oceans Trapped Heat During This 'Global Warming Pause,' Which Won't Last Long

After 30 years of unprecedented warming, the rise of global average air temperatures has slowed since 1999, leading to what skeptics and the media have dubbed a "global warming pause."

"Every week there's a new explanation of the hiatus," Ka-Kit Tung, a professor of applied mathematics and adjunct faculty member in atmospheric sciences at the University of Washington said in a release.

In a new study published Thursday in Science magazine, Tung argues that the reason surface temperatures haven't risen is that a natural cycle of ocean currents has dragged heat nearly a mile down into the Atlantic and Southern oceans.

This naturally occurs in a cycle, which lasts about 30 years. This one began around 2000, meaning that in about 15 years, the warm water will return to the surface and allow air temperatures to rapidly increase again.

The cycle is regulated by salt content in water in the North Atlantic. When warmer waters cause the ice to melt, the denser salt water sinks and takes the heat with it, which gradually slows down the current. Tung observed that while deep water continues to warm up, the surface of the North Atlantic has record-high saltiness.

The study disputes previous theories that the Pacific Ocean was responsible for storing surface heat. While the temperature under the Pacific has changed as well, the study concluded that it's not nearly enough to compensate for the entire global warming hiatus.

Tung and Chen also looked at historical data to see whether these 30-year cycles of warming and cooling stretch back for centuries. The difference now is that the next warming cycle will occur on top of human-influenced global warming.

"We are not talking about a normal situation because there are so many other things happening due to climate change," Tung said. Even during the current cooling cycle, glaciers in Antarctica and Greenland are melting faster than ever. This additional freshwater could disrupt the cycle.

So in other words, enjoy the next decade, because it might start getting really damn hot in 2025.