Atlantic slows warming, temperature rises seen resuming from 2030: study

OSLO, Thu Aug 21, 2014 2:04pm EDT

OSLO,(Reuters) - 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 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," Ka-Kit Tung, of the University of Washington in Seattle and a co-author of Thursday's study in the journal Science, told Reuters.

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 meters (5,000 feet), part of a natural shift for the ocean that typically lasts about three decades.

It said a return to a warmer period, releasing more heat stored in the ocean, was likely to start around 2030. When it does, "another episode of accelerated global warming should ensue", the authors wrote.

Almost 200 governments aim to agree a deal to combat climate change at a summit in Paris in late 2015 and the hiatus has heartened skeptics who doubt there is an urgent need for a trillion-dollar shift from fossil fuels to renewable energies.

Several previous studies have suggested that the larger Pacific Ocean is the likely site of the "missing heat" from man-made greenhouse gases, perhaps linked to a series of La Nina cooling events in the Pacific in recent years.

Other suggestions for the slowdown in warming have included a rise in industrial pollution that is blocking sunlight.

SHIFT IN SALINITY?

A separate team of scientists writing in the journal Nature Geoscience on Sunday said that factors including swings in the sun’s output and sun-blocking dust from volcanic eruptions may account for gaps in understanding the warming trends.

In addition, La Nina cooling events in the Pacific Ocean had played a role, according to the report that examined why computer models of the climate had over-estimated temperature rises in the past decade.

But no one knows for sure.

"It will be interesting to see how and if these ideas are connected" with the theory of the Atlantic, lead author Markus Huber said of the study by the Institute for Atmospheric and Climate Science at ETH Zurich.

Thursday's study said a shift in salinity may have caused more heat to be transferred to the depths of the Atlantic.

Warm, salty water from the tropics flows north on the Gulf Stream in the Atlantic and sinks when it meets cooler water. The "great ocean conveyor belt" then makes cold water flow in the depths to the Southern Ocean.

Even though global warming has slowed, 13 of the 14 warmest years on record have been this century, according to U.N. estimates.

A U.N. panel says it is at least 95 percent certain that human emissions, rather than natural variations in the climate, are the main cause of rising temperatures since 1960 that have caused more heatwaves, downpours and rising sea levels.

(Editing by Gareth Jones)

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Comments (6)
WillHolder wrote:
I vaguely remember hearing something about the science being settled. Correct me if I’m wrong, but wasn’t there a group of people labeled deniers and idiots that suggested there hasn’t been any warming since the late 90′s and that natural mechanisms are responsible for changes to the climate. Funny.

Aug 21, 2014 6:41pm EDT  --  Report as abuse
whatsnew wrote:
” a slowdown in the pace of warming at the Earth’s surface since about 1998 that has puzzled experts….” well maybe they’d be less puzzled if they stopped trying to make their model fit an agenda. There is no slowdown, only a false premise and equally faulty models.
So bottom line forget all the claims of climate change the models are flawed. They are clutching at straws to salvage a belief/agenda.

Aug 21, 2014 6:57pm EDT  --  Report as abuse
For the sake of integrity, so-called “scientists” should disclose the extent to which their salary and/or prestigious career is government-funded prior to issuing statements. Secondly, reporters should remind readers of the global-warming data fraud scandal at the UN. Third, reporters should remind readers that the United States EPA website fails to disclose the existence of several massive solar radiation cycles that effect global temperatures. And finally, reporters should remind readers that the US EPA (along with the so-called “scientists”) are claiming – essentially – that 3% of earth’s man-made greenhouse gases cause global warming but not the 97% of greenhouse gases that are natural. That is absurd.

Aug 21, 2014 7:23pm EDT  --  Report as abuse
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