The temperature graph has flattened out since the late 1990's, while CO2 continues to rise. The latest attempt to explain this anomaly is that global warming is being absorbed by the oceans.
ScienceDaily — The planet's deep oceans at times may absorb enough heat to flatten the rate of global warming for periods of as long as a decade even in the midst of longer-term warming, according to a new analysis led by the National Center for Atmospheric Research (NCAR).
The study, based on computer simulations of global climate, points to ocean layers deeper than 1,000 feet (300 meters) as the main location of the "missing heat" during periods such as the past decade when global air temperatures showed little trend. The findings also suggest that several more intervals like this can be expected over the next century, even as the trend toward overall warming continues.
"We will see global warming go through hiatus periods in the future," says NCAR's Gerald Meehl, lead author of the study. "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 research, by scientists at NCAR and the Bureau of Meteorology in Australia, is published online in Nature Climate Change. Funding for the study came from the National Science Foundation, NCAR's sponsor, and the Department of Energy.