Atlantic Ocean has temporarily slowed global warming - study

[theHandpuppet]

The Irish Times
August 21, 2014

Atlantic Ocean has temporarily slowed global warming - study
Sea soaked up vast heat but temperatures to rise from 2030, researchers say

The Atlantic Ocean has masked global warming this century by soaking up vast amounts of heat from the atmosphere in a shift likely to reverse from around 2030 and spur fast temperature rises, scientists have said.

The theory is the latest explanation for a slowdown in the pace of warming at the Earth’s surface since about 1998 that has puzzled experts because it conflicts with rising greenhouse gas emissions, especially from emerging economies led by China.

“We’re pointing to the Atlantic as the driver of the hiatus,” Professor Ka-Kit Tung, of the University of Washington in Seattle and a co-author of today’s study in the journal Science has said.

The study said an Atlantic current carrying water north from the tropics sped up this century and sucked more warm surface waters down to 1,500 metres (5,000 feet), part of a natural shift for the ocean that typically lasts about three decades....

MORE at http://www.irishtimes.com/news/environment/atlantic-ocean-has-temporarily-slowed-global-warming-study-1.1904238

[Demeter]

1. "Theories" is it? How about a faulty model?

[NickB79]

2. Please, do elaborate

We're all LOVE to hear what you really think about man-made global warming

[muriel_volestrangler]

3. Link to paper, and Nature article about it

http://www.sciencemag.org/content/345/6199/897

This change in ocean circulation is linked to cyclical changes in salinity in high-latitude waters. When the circulation patterns are slow, warm surface waters have more time to lose moisture to evaporation. This makes them increasingly saline — and hence, denser — when they arrive at the high-latitude zones, where they sink. Eventually this reaches a critical point, at which fast-sinking waters speed up the current.

But Tung says that the effect will not last forever. As currents speed up, the warm waters lose less moisture to evaporation and become fresher. The heat that the water carries also causes glaciers, ice caps and pack ice to melt, releasing fresh water into the surface ocean. Eventually, the salinity lowers enough that waters do not sink as rapidly at high latitudes, slowing the global circulation pattern.

Temperature data from central England suggests that this process has been going on for roughly 350 years, on an approximately 70-year cycle.

http://www.nature.com/news/atlantic-ocean-key-to-global-warming-pause-1.15755