Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
. Earth Science News .




CLIMATE SCIENCE
Ancient climate questions could improve today's climate predictions
by Staff Writers
San Francisco CA (SPX) Apr 04, 2013


File image.

About 4 to 5 million years ago, the Earth was warmer than today. Now that greenhouse gas pollution has the planet's temperature rising again, researchers want to know more about why this early Pliocene period was so warm, with the hopes of improving future climate predictions.

A new study in the journal Nature concludes that it is difficult to model the exact conditions behind the pattern of warming in the early Pliocene. None of the proposed mechanisms-from high carbon dioxide levels to changes in global ocean circulation patterns-can explain why the ancient warm period looks the way it does.

The findings raise the question of whether climate models for the early Pliocene might be missing key processes. If researchers can uncover these missing processes, they can apply them to models of modern climate and improve future climate predictions, says San Francisco State University Assistant Professor of Geosciences Petra Dekens, a co-author on the Nature study.

"It's very hard to look at a climate record from the past and say this directly applies to modern climate," Dekens says. "But what it does do is help us think about what the gaps might be in our models, what are the uncertainties in our current models, and whether those uncertainties could be important."

While the early Pliocene has attracted the interest of researchers looking to understand today's warming climate, the planet was a markedly different place 4 to 5 million years ago. In particular, while the highest sea surface temperatures were relatively stable, there were only small differences in sea surface temperature moving from the equator to the poles, or moving east to west.

Things began to change after the early Pliocene. The pool of warm water spreading out from the equator began to shrink toward lower latitudes, and east-west differences in sea surface temperature began to develop. Overall, the planet's climate shifted toward cooler temperatures.

The Nature authors were able to see this broad shift in climate by examining a wealth of already-published data on sea surface temperatures. "Very few of these records existed 10 years ago, but we're now at this point where we have records in high latitudes and low latitudes," Dekens said.

Ancient sea surface temperatures can be reconstructed in a variety of ways. Dekens studies sea surface temperatures by looking at the ratio of minerals like magnesium and calcium in the shells of tiny single-celled sea animals, found in sediment cores drawn from the deep sea. These ratios reflect sea temperature at the time the shells were deposited.

The records allowed the researchers to see that the early Pliocene climate was "structurally different" from today's climate, Dekens said. "It's not just that the absolute temperature in any one location is different, it's that the patterns are different."

Dekens' colleagues constructed several models to try and recreate the sea surface temperature conditions of the early Pliocene, but none of the expected "drivers" of climate that they tested could account for all the major features of the ancient climate.

For instance, the researchers found that increases in greenhouse gases and changes in ocean circulation could not reproduce the early Pliocene climate in their models.

Other tweaks to the models--reducing the reflection of sunlight by tropical clouds, for instance-did bring the models closer to matching the early Pliocene. But they still fell short of explaining the full pattern.

The paper, "Patterns and mechanisms of early Pliocene warmth," was published today in the 4 April issue of the journal Nature.

.


Related Links
San Francisco State University
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




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





CLIMATE SCIENCE
Economist warns of 'radical' climate change, millions at risk
Washington (AFP) April 2, 2013
The author of an influential 2006 study on climate change warned Tuesday that the world could be headed toward warming even more catastrophic than expected but he voiced hope for political action. Nicholas Stern, the British former chief economist for the World Bank, said that both emissions of greenhouse gas and the effects of climate change were taking place faster than he forecast seven y ... read more


CLIMATE SCIENCE
Fukushima fuel cooling system stops again:TEPCO

Environmental policies matter for growing megacities

Finland's Fennovoima in talks with Rosatom over reactor

US drivers talk and text as much as ever

CLIMATE SCIENCE
Theory and practice key to optimized broadband, low-loss optical metamaterials

CWRU-led scientists build material that mimics squid beak

Watching fluid flow at nanometer scales

Michigan Tech researcher slashes optics laboratory costs

CLIMATE SCIENCE
Temperature difference between hemispheres could shift rainfall patterns

Chinese foreign fisheries catch 12 times more than reported

Shark tooth weapons reveal missing shark species in Central Pacific islands

Tiny Grazers Play Key Role in Marine Ecosystem Health

CLIMATE SCIENCE
New models predict drastically greener Arctic in coming decades

Ice cores preserve 1,800 years of climate

2013 Wintertime Arctic Sea Ice Maximum Fifth Lowest on Record

Thin clouds drove Greenland's record-breaking 2012 ice melt

CLIMATE SCIENCE
'World's greatest' chef Adria seeks digital legacy

China paper says farm sector raises bird flu risk

Italy bids to close gap in wine exports to China

Birch juice season takes Latvia by storm

CLIMATE SCIENCE
Argentina floods caused $5 billion in damage

Italy marks fourth anniversary of L'Aquila quake

7.1-magnitude quake causes panic in Indonesia's Papua

Quake shakes buildings in Manila

CLIMATE SCIENCE
Thousands in Darfur seek protection after fighting

Congolese pygmy seeks to enlighten his kin

Guinea-Bissau ex-navy chief held on US drug charges

S.Africa pulls troops from C.Africa after deadly firefight

CLIMATE SCIENCE
Women and men perform the same in math

Scientists identify brain's 'molecular memory switch'

Researchers successfully map fountain of youth

First evidence of Neanderthal/human mix




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal 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