Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. 24/7 Space News .




WATER WORLD
The relationship between CO2 concentrations and sea level
by Staff Writers
Southampton UK (SPX) Jan 07, 2013


According to the study, sea level stays more or less constant for CO2 changes between 400 and 650 parts per million and it is only for CO2 levels above 650 parts per million that the researchers again saw a strong sea level response for a given CO2 change.

By comparing reconstructions of atmospheric CO2 concentrations and sea level over the past 40 million years, researchers based at the National Oceanography Centre, Southampton have found that greenhouse gas concentrations similar to the present (almost 400 parts per million) were systematically associated with sea levels at least nine metres above current levels.

The study determined the 'natural equilibrium' sea level for CO2 concentrations ranging between ice-age values of 180 parts per million and ice-free values of more than 1,000 parts per million.

It takes many centuries for such an equilibrium to be reached, therefore whilst the study does not predict any sea level value for the coming century, it does illustrate what sea level might be expected if climate were stabilized at a certain CO2 level for several centuries.

Lead author Dr Gavin Foster, from Ocean and Earth Science at the University of Southampton which is based at the centre, said, "A specific case of interest is one in which CO2 levels are kept at 400 to 450 parts per million, because that is the requirement for the often mentioned target of a maximum of two degrees global warming."

The researchers compiled more than two thousand pairs of CO2 and sea level data points, spanning critical periods within the last 40 million years. Some of these had climates warmer than present, some similar, and some colder. They also included periods during which global temperatures were increasing, as well as periods during which temperatures were decreasing.

"This way, we cover a wide variety of climate states, which puts us in the best position to detect systematic relationships and to have the potential for looking at future climate developments," said co-author Professor Eelco Rohling, also from Ocean and Earth Science at the University of Southampton.

The researchers found that the natural relationship displays a strong rise in sea level for CO2 increase from 180 to 400 parts per million, peaking at CO2 levels close to present-day values, with sea level at 24 +7/-15 metres above the present, at 68 per cent confidence limits.

"This strong relationship reflects the climatic sensitivity of the great ice sheets of the ice ages," said Dr Foster. "It continues above the present level because of the apparently similar sensitivity of the Greenland and West Antarctic ice sheets, plus possibly some coastal parts of East Antarctica."

According to the study, sea level stays more or less constant for CO2 changes between 400 and 650 parts per million and it is only for CO2 levels above 650 parts per million that the researchers again saw a strong sea level response for a given CO2 change.

"This trend reflects the behaviour of the large East Antarctic ice sheet in response to climate changes at these very high CO2 levels. An ice-free planet, with sea level 65 metres above the present, occurred in the past when CO2 levels were around 1200 parts per million."

Professor Rohling said, "Sea level rises to these high values will take many centuries, or even millennia, but the implications from the geological record are clear - for a future climate with maximum warming of about two degrees Centigrade, that is with CO2 stabilized at 400 to 450 parts per million, sea level is set to steadily rise for many centuries, towards its natural equilibrium position at around 24 +7/-15 metres, at 68 per cent confidence.

In Intergovernmental Panel on Climate Change terms, this is a likely rise of at least nine metres above the present. Previous research indicates that such rises above present sea level may occur at rates of roughly one metre per century."

Based on these results, which document how the Earth system has operated in the past, future stabilization of CO2 at 400-450 parts per million is unlikely to be sufficient to avoid a significant steady long-term sea level rise.

The study is published this week online ahead of print in Proceedings of the National Academy of Sciences of the United States of America (PNAS manuscript # 2012-16073R). Co-authors are Dr Gavin Foster (Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton SO14 3ZH, UK) and Professor Eelco J. Rohling (Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton SO14 3ZH, UK; and from 1 March 2013, Research School of Earth Sciences, The Australian National University, Canberra, Australia).

.


Related Links
National Oceanography Centre, Southampton
Water News - Science, Technology and Politics






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





WATER WORLD
Outrage over Hong Kong's 'shark fin rooftop'
Hong Kong (AFP) Jan 3, 2013
Hong Kong conservationists expressed outrage Thursday after images emerged of a factory rooftop covered in thousands of freshly sliced shark fins, as they called for curbs on the "barbaric" trade. The southern Chinese city is one of the world's biggest markets for shark fins, which are used to make soup that is an expensive staple at Chinese banquets and viewed by many Asians as a rare delic ... read more


WATER WORLD
Mission would drag asteroid to the moon

Russia designs manned lunar spacecraft

GRAIL Lunar Impact Site Named for Astronaut Sally Ride

NASA probes crash into the moon

WATER WORLD
Ancient Water-rich Meteorite Linked to Martian Crust

Stanford researchers develop acrobatic space rovers to explore moons and asteroids

Researchers Identify Water Rich Meteorite Linked To Mars Crust

Mars meteorite has significant water

WATER WORLD
2012 in Polish space activities

Captain's log: real space chat for Star Trek crew

Congress Approves Bill Supporting Human Space Exploration

China's Chengdu aiming to be world's next Silicon Valley

WATER 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

WATER WORLD
Station Crew Ringing in New Year

Expedition 34 Ready to Ring in New Year

New ISS crew docked at Space Station

Expedition 34 Spends Christmas in Space

WATER WORLD
CSF Applauds Passage Of Risk-Sharing Regime Extension For Launch Industry

Rokot Launch Set for January 15

Russian rocket launch rescheduled

Investigation into Proton Launch Anomaly Continues as Root Cause is being Evaluated

WATER WORLD
Billions and Billions of Planets

ALMA Shows How Young Star and Planets Grow Simultaneously

ALMA Sheds Light on Planet-Forming Gas Streams

A stray planet

WATER WORLD
Liquid jets and bouncing balls combine for surprising results

How computers push on the molecules they simulate

Shortage of helium has business impact

Corning to debut tougher Gorilla Glass




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