Deep Oceans Could Delay Effects of Global Warming for Decades

The world's deep oceans can absorb enough heat to conceal the effects of global warming for up to a decade, according to a new study by the U.S. National Center for Atmospheric Research.

Earth's "missing heat" has long been a mystery for scientists, as greenhouse gas emissions kept increasing but global air temperatures remained static.

Scientists had long speculated that world temperature should have risen more than it did in the decade between 2000 and 2010, leading NCAR researchers to suggest that the missing heat was accumulating somewhere other than in the atmosphere.

Their theory was borne out in a new study which used computer simulations of global climate to analyse temperature fluctuations over the last 10 years.

Their findings indicate that the 'missing heat' was actually trapped in ocean layers deeper than 1,000 feet during periods like the last decade and that similar cycles can be expected over the next century.

"We will see global warming go through hiatus periods in the future," NCAR's Gerald Meehl, lead author of the study, told TG Daily.

"However, these periods would likely last only about a decade or so, and warming would then resume. This study illustrates one reason why global temperatures do not simply rise in a straight line."

Meehl and the other researchers used the Community Climate System Model to run five simulations of global temperatures, accounting for the interactions among atmosphere, land, oceans and sea ice and factoring in human contributions like greenhouse gas emissions.

During these periods, the excess heat was absorbed into deep ocean water due to "changes in ocean circulation," rather than released into the atmosphere.

"This study suggests the missing energy has indeed been buried in the ocean," NCAR's Kevin Trenberth, a co-author of the study, said. "The heat has not disappeared, and so it cannot be ignored. It must have consequences."