Oceans May Explain Slowdown in Climate Change
Climate change could get worse quickly if huge amounts of extra heat absorbed by the oceans are released back into the air, scientists said after unveiling new research showing that oceans have helped mitigate the effects of warming since 2000.
Reuters
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By Environment Correspondent Alister Doyle
OSLO (Reuters) – Climate change could get worse quickly if huge amounts of extra heat absorbed by the oceans are released back into the air, scientists said after unveiling new research showing that oceans have helped mitigate the effects of warming since 2000.
Heat-trapping gases are being emitted into the atmosphere faster than ever, and the 10 hottest years since records began have all taken place since 1998. But the rate at which the earth’s surface is heating up has slowed somewhat since 2000, causing scientists to search for an explanation for the pause.
Experts in France and Spain said on Sunday that the oceans took up more warmth from the air around 2000. That would help explain the slowdown in surface warming but would also suggest that the pause may be only temporary and brief.
“Most of this excess energy was absorbed in the top 700 meters (2,300 ft) of the ocean at the onset of the warming pause, 65 percent of it in the tropical Pacific and Atlantic oceans,” they wrote in the journal Nature Climate Change.
Lead author Virginie Guemas of the Catalan Institute of Climate Sciences in Barcelona said the hidden heat may return to the atmosphere in the next decade, stoking warming again.
“If it is only related to natural variability then the rate of warming will increase soon,” she told Reuters.
Caroline Katsman of the Royal Netherlands Meteorological Institute, an expert who was not involved in the latest study, said heat absorbed by the ocean will come back into the atmosphere if it is part of an ocean cycle such as the “El Nino” warming and “La Nina” cooling events in the Pacific.
She said the study broadly confirmed earlier research by her institute but that it was unlikely to be the full explanation of the warming pause at the surface, since it only applied to the onset of the slowdown around 2000.
THRESHOLD
The pace of climate change has big economic implications since almost 200 governments agreed in 2010 to limit surface warming to less than 2 degrees Celsius (3.6 F) above pre-industrial levels, mainly by shifting from fossil fuels.
Surface temperatures have already risen by 0.8 C. Two degrees is widely seen as a threshold for dangerous changes such as more droughts, mudslides, floods and rising sea levels.
Some governments, and skeptics that man-made climate change is a big problem, argue that the slowdown in the rising trend shows less urgency to act. Governments have agreed to work out, by the end of 2015, a global deal to combat climate change.
Last year was ninth warmest since records began in the 1850s, according to the U.N.’s World Meteorological Organization, and 2010 was the warmest, just ahead of 1998. Apart from 1998, the 10 hottest years have all been since 2000.
Guemas’s study, twinning observations and computer models, showed that natural La Nina weather events in the Pacific around the year 2000 brought cool waters to the surface that absorbed more heat from the air. In another set of natural variations, the Atlantic also soaked up more heat.
“Global warming is continuing but it’s being manifested in somewhat different ways,” said Kevin Trenberth, of the U.S. National Center for Atmospheric Research. Warming can go, for instance, to the air, water, land or to melting ice and snow.
Warmth is spreading to ever deeper ocean levels, he said, adding that pauses in surface warming could last 15-20 years.
“Recent warming rates of the waters below 700 meters appear to be unprecedented,” he and colleagues wrote in a study last month in the journal Geophysical Research Letters.
The U.N. panel of climate scientists says it is at least 90 percent certain that human activities – rather than natural variations in the climate – are the main cause of warming in recent decades.
(Reporting by Alister Doyle, Environment Correspondent; Editing by Peter Graff)
Reuters
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1. sault 03:53 PM 4/7/13
We need to reduce greenhouse gas emissions ASAP. Since fossil fuel pollution damages the environment, harms our health and these fuels will eventually run out, climate change is just another reason to start the switch over to alternatives as fast as possible. Even without accounting for the costs of pollution, solar, wind and a whole host of clean energy technologies are becoming just as cheap as dirty fossil fuels. All we need is to ignore all the bellyaching from the people who have gotten very rich polluting our environment with fossil fuel waste and make the transition into a clean and sustainable 21st Century.
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2. jrfk2 04:10 PM 4/7/13
Unfortunately our foresight only seems to extend as far as our hands … when the inter-twined systems that humans depend on start breaking down .. then there will be a mad scramble to “fix” it .. then there will be a mad scramble to control the remaining clean water .. then it will just be mad. Then it will be the ants’ turn.
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3. Carlyle 05:45 PM 4/7/13
But but but…the AGW adherants have been adamant that there has been no pause. We must gird ourselves immediately for imminent hurricanes, cyclones, floods, drought, earthquakes, tsunamis, extinctions, disease, millions of climate refugees, & many other catastrophes.
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4. geojellyroll 07:19 PM 4/7/13
“Warmth is spreading to ever deeper ocean levels, he said, adding that pauses in surface warming could last 15-20 years.”
Too funny. Already making excuses why surface temperatures cooled in 2012 and the doomsday scenarios predicted in the 90’s have fallen flan…’climate models’…ya, sure.
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5. robmo 07:20 PM 4/7/13
More excuses for why the numbers don’t match the hype form the Global Warming crowd. In addition, there’s no way on God’s green earth that these ideologues will be able to link CO2 output to any warming, unless of course, they fudge the data which they tend to be very fond of doing.
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6. sault in reply to Carlyle 10:39 PM 4/7/13
Silly Carlyle, reading comprehension is for non-climate deniers!
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7. sault in reply to robmo 10:43 PM 4/7/13
So, you guys are denying the OBSERVED spectral properties of CO2 now? Seriously, lay off the fossil fuel propaganda a little and read some REAL science. Google Scholar has all the papers you’ll ever need.
http://scholar.google.com/scholar?as_ylo=2009&q=CO2+greenhouse+effect&hl=en&as_sdt=0,5
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8. sault in reply to geojellyroll 10:45 PM 4/7/13
Classic ignorance on climate science coming from the denier camp. You know that you can’t make a determination on whether temperatures “cooled” with just 1 year of data, right?
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9. Dr. Strangelove 10:46 PM 4/7/13
Easy to check if heat is spreading to deep oceans. Is the decadal sea level rise increasing or decreasing? Increasing means warming, decreasing means cooling. If the Antarctic ice sheet is not melting, then sea level rise must be due to thermal expansion of seawater.
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10. sault in reply to Carlyle 01:37 AM 4/8/13
You REALLY have to look at what’s ACTUALLY going on in the real world. This video about arctic sea ice ,ight help:
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