September 19, 2011
Oceans May Accumulate ‘Missing’ Heat From Global Warming
Researchers believe that they have discovered the location of the so-called "missing heat" that could have caused air temperatures to increase as greenhouse gas emissions over the past decade.
Using computer simulations, scientists at the National Center for Atmospheric Research (NCAR) and the Australian Bureau of Meteorology have concluded that this heat might be absorbed in the planet's oceans, at depths of 1,000 feet of more, according to a September 18 NCAR press release.
Additionally, according to Reuters reports, the researchers concluded that this phenomenon could occur for several years at a time, and that it could happen periodically throughout the rest of this century.
"We will see global warming go through hiatus periods in the future," NCAR's Gerald Meehl, lead author of the study, said in a statement Sunday. "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."
The findings have been published online in the journal Nature Climate Change.
According to the NCAR media advisory, the decade of the 2000s was the warmest 10-year period, worldwide, in over a century of recorded weather data. However, it wasn't until 2010 that the previous single-year mark for warmest global temperatures, set in 1998, had been equaled -- despite the fact that greenhouse gas emissions rose throughout the decade, and that satellite measurements "showed that the discrepancy between incoming sunshine and outgoing radiation from Earth actually increased."
That led NCAR researchers Kevin Trenberth and John Fasullo to determine, as part of a study published last year in the journal Science, that the heat had to be accumulating somewhere on the planet. That led Trenberth, Fasullo, Meehl, and colleagues to continue their work, analyzing five computer simulations of global temperatures in an attempt to pinpoint exactly where that might be.
They discovered that during the so-called "hiatus periods" (times when temperatures would stabilize for a while before increasing again), the temperature of deep ocean areas below the 1,000 foot mark increased by 18% to 19% more than during other times.
"This study suggests the missing energy has indeed been buried in the ocean," Trenberth, credited as a co-author of the new study, said in a statement, according to Reuters. "The heat has not disappeared and so it cannot be ignored. It must have consequences."
The study was funded by the National Science Foundation (NSF) and the U.S. Department of Energy.
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