Subscribe free to our newsletters via your
. 24/7 Space News .




ICE WORLD
Clouds Could Explain How Snowball Earth Thawed Out
by Staff Writers
Chicago IL (SPX) Nov 14, 2012


illustration only

Glaciation events during the Neoproterozoic (524-to-1,000 million years ago) and Paleoproterozoic (1,600-to-2,500 million years ago) periods - events that spawned ice ages that persisted for millions of years at a time - may have seen glacier ice encircle the planet in a frosty planetary configuration known as a Snowball Earth.

Whether the planet could have existed in such a state, however, is a matter of considerable debate. An elevated planetary albedo, caused by the planet being covered in reflective snow and ice, would mean that a Snowball Earth would reinforce itself.

With no known mechanisms able to fully explain how the planet could have thawed out from such a state, some scientists suspect that Snowball Earth never happened.

However, using a series of global general circulation models, Abbot et al. find that the greenhouse potential of clouds, which had been overlooked in previous research, could explain how a Snowball Earth may have melted.

Previous modeling research found that to thaw out a glacier that covered the planet would require carbon dioxide to account for up to 20 percent of the atmosphere by volume. Paleogeochemical evidence, however, shows that carbon dioxide levels reached only 1 percent to 10 percent.

The model used for the earlier research, the authors find, ignored the warming potential of clouds. Clouds not only trap infrared radiation near Earth's surface, warming the planet, but also reflect incoming sunlight, cooling the planet. In the modern climate, both effects are important.

However, set against a planet encompassed in ice, clouds' reflectivity becomes less important, and the overall effect of clouds is to warm the planet.

By accounting for the heat-trapping effects of clouds, the authors find that the atmospheric carbon dioxide concentration required to drive deglaciation is 10-100 times lower than previous research suggested, a concentration that fits within observed levels.

Clouds and Snowball Earth Deglaciation- Geophysical Research Letters, doi: 10.1029/2012GL052861, 2012.

.


Related Links
Title: Clouds and Snowball Earth Deglaciation
Beyond the Ice Age






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








ICE WORLD
Carbon dioxide - our salvation from a future ice age?
Gothenburg, Sweden (SPX) Nov 09, 2012
Mankind's emissions of fossil carbon and the resulting increase in temperature could prove to be our salvation from the next ice age. According to new research from the University of Gothenburg, Sweden, the current increase in the extent of peatland is having the opposite effect. "We are probably entering a new ice age right now. However, we're not noticing it due to the effects of carbon ... read more


ICE WORLD
China's Chang'e-3 to land on moon next year

Moon crater yields impact clues

Study: Moon basin formed by giant impact

NASA's LADEE Spacecraft Gets Final Science Instrument Installed

ICE WORLD
Mars orbiter back online after system swap

What Arctic Rocks Say About Mars: An Interview with Hans Amundsen

More Driving And Imaging At 'Matijevic Hill'

Curiosity Team Switches Back to Earth Time

ICE WORLD
SciTechTalk: All work and no play?

Get some bed rest - all 21 days of it

Latest China military hardware displayed at airshow

Obama Win Keeps NASA's Space Plans on Course

ICE WORLD
Mr Xi in Space

China plans manned space launch in 2013: state media

China to launch manned spacecraft

Tiangong 1 Parked And Waiting As Shenzhou 10 Mission Prep Continues

ICE WORLD
Russia loses contact with satellites, space station

Cut in Russian link to space station not serious: NASA

Crew Prepares for Spacewalk After Progress Docks

Crew Preparing for Cargo Ship, Spacewalk

ICE WORLD
Arianespace's fourth Spaceport mission with Soyuz ready for fueling

Ariane 5's sixth launch of 2012

Ariane 5 is poised for Arianespace's launch with the EUTELSAT 21B and Star One C3 satellites

Ariane 5 orbits EUTELSAT 21B and Star One C3 satellites

ICE WORLD
Lost in Space: Rogue Planet Spotted?

Lowell Astronomer, Collaborators Point The Way For Exoplanet Search

Lonely planet: Orphan world spotted in deep space

Discovery of a Giant Gap in the Disk of a Sun-like Star May Indicate Multiple Planets

ICE WORLD
Chinese LED firm plans record investment in Taiwan

US to station powerful radar, space telescope in Australia

Afghan women learn literacy through mobile phones

36 in one fell swoop as researchers observe impossible ionization




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