Subscribe free to our newsletters via your
. Earth Science News .




CLIMATE SCIENCE
Atlantic and Pacific oscillations caused 'false pause' in warming
by Staff Writers
University Park PA (SPX) Feb 27, 2015


File image.

The recent slowdown in climate warming is due, at least in part, to natural oscillations in the climate, according to a team of climate scientists, who add that these oscillations represent variability internal to the climate system. They do not signal any slowdown in human-caused global warming.

"We know that it is important to distinguish between human-caused and natural climate variability so we can assess the impact of human-caused climate change on a variety of phenomena including drought and weather extremes," said Michael Mann, Distinguished Professor of Meteorology, Penn State.

"The North Atlantic and North Pacific oceans appear to be drivers of substantial natural, internal climate variability on timescales of decades."

Mann, Byron A. Steinman, assistant professor of geological sciences, University of Minnesota-Duluth and a former Penn State National Science Foundation postdoctoral fellow and Penn State researcher Sonya K. Miller looked at a combination of real-world observational data and state-of-the-art climate model simulations used in the most recent report of the Intergovernmental Panel on Climate Change to understand the competing contributions to climate variability in the Northern Hemisphere during the historic era.

The Atlantic Multidecadal Oscillation (AMO) describes how North Atlantic sea-surface temperatures tend to oscillate with a periodicity of about 50 to 70 years. The Pacific Decadal Oscillation (PDO) varies over a broader range of timescales. The researchers looked only at the portion of the PDO that was multidecadal -- what they term the Pacific multidecadal oscillation (PMO).

Using a wide variety of climate simulations, the researchers found that the AMO and PMO are not significantly correlated; they are not part of the global "stadium wave" oscillation, as some researchers had claimed. What they found was that the Northern Hemisphere was warming more slowly, not because of the AMO -- which has been relatively flat -- but because of a sharply down-trending PMO.

The researchers conclude that the down-trending PMO and the unusual slowing of warming over the past decade are tied to heat burial beneath the tropical Pacific and a tendency for sustained La Nina type conditions. While there is paleoclimate data suggesting that this type of response could come from subtle features of climate change itself that climate models do not currently capture, the researchers note that the most likely explanation is the random excursions of the AMO.

"Our findings have strong implications for the attribution of recent climate changes," said Mann. "Internal multidecadal variability in Northern Hemisphere temperatures likely offset anthropogenic warming over the past decade."

The researchers conclude that given past historical patterns of variation in the AMO and PMO, this situation will likely reverse and add to human induced warming in the future.


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only


.


Related Links
Penn State
Climate Science News - Modeling, Mitigation Adaptation






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle








CLIMATE SCIENCE
French, Philippine leaders appeal for climate action
Manila (AFP) Feb 26, 2015
French President Francois Hollande and Philippine leader Benigno Aquino appealed Thursday for urgent global action on climate change, seeking to build momentum for a planned historic accord at a UN summit in Paris. On the first day of Hollande's visit to the Philippines, the leaders offered a show of unity they said could serve as a model for rich and poor nations who have long been divided ... read more


CLIMATE SCIENCE
Afghan president pledges relief fund for avalanche victims

Death toll from Afghan avalanches tops 200: officials

More than 100 dead in Afghanistan avalanches: officials

Calling on satellites in alpine rescues

CLIMATE SCIENCE
Australia researchers create 'world first' 3D-printed jet engines

New NASA Space Cowboy Deploys Its 'Lasso'

Watching bonds form using femtosecond X-ray liquidography

New research predicts when, how materials will act

CLIMATE SCIENCE
New algal species helps corals survive in the hottest reefs on the planet

Isolated wetlands have significant impact on water quality

Climate-warmed leaves change lake ecosystems

Japan developing 12,000-meter-depth submersible to search seafloor

CLIMATE SCIENCE
The past might tell what the future holds for Greenland meltdown

NASA measures frigid cloud top temps of the Arctic air outbreak

Iceland rises as its glaciers melt from climate change

Arctic sea ice loss expected to be bumpy in the short term

CLIMATE SCIENCE
Regulating genome-edited crops that aren't GMOs

Australia to tighten food labelling laws after China scare

Gene may help reduce GM contamination

Farmers can better prevent nutrient runoff based on land characteristics

CLIMATE SCIENCE
Flooding in Madagascar capital kills at least 14: rescuers

Gaza floods: dispelling the myth about Israeli 'dams'

New volcano island getting big in Japan

Volcanic ash forces Mexican airport closure

CLIMATE SCIENCE
Zambia's ex-mines minister jailed for graft over Chinese licence

Mali government signs peace deal, Tuareg rebels delay

Nigerian army chief visits Baga, vows 'war is almost ended'

WHO seeks $1 bn more for four conflict-hit countries

CLIMATE SCIENCE
How does the human brain tackle problems it did not evolve to solve?

Nanotech and genetic interference may tackle untreatable brain tumors

Brain makes decisions with same method used to break WW2 Enigma code

Ancient and modern cities aren't so different




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.