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

Evidence from warm past confirms recent IPCC estimates of climate sensitivity
by Staff Writers
Southampton, UK (SPX) Feb 09, 2015

File image.

New evidence showing the level of atmospheric CO2 millions of years ago supports recent climate change predications from the Intergovernmental Panel on Climate Change (IPCC).

A multinational research team, led by scientists at the University of Southampton, has analysed new records showing the CO2 content of the Earth's atmosphere between 2.3 to 3.3 million years ago, over the Pliocene.

During the Pliocene, the Earth was around 2C warmer than it is today and atmospheric CO2 levels were around 350-400 parts per million (ppm), similar to the levels reached in recent years.

By studying the relationship between CO2 levels and climate change during a warmer period in Earth's history, the scientists have been able to estimate how the climate will respond to increasing levels of carbon dioxide, a parameter known as 'climate sensitivity'.

The findings, which have been published in Nature, also show how climate sensitivity can vary over the long term.

"Today the Earth is still adjusting to the recent rapid rise of CO2 caused by human activities, whereas the longer-term Pliocene records document the full response of CO2-related warming," says Southampton's Dr Gavin Foster, co-author of the study.

"Our estimates of climate sensitivity lie well within the range of 1.5 to 4.5C increase per CO2 doubling summarised in the latest IPCC report. This suggests that the research community has a sound understanding of what the climate will be like as we move toward a Pliocene-like warmer future caused by human greenhouse gas emissions."

Lead author of the study, Dr Miguel Martinez-Boti, also from Southampton said: "Our new records also reveal an important change at around 2.8 million years ago, when levels rapidly dropped to values of about 280 ppm, similar to those seen before the industrial revolution. This caused a dramatic global cooling that initiated the ice-age cycles that have dominated Earth's climate ever since."

The research team also assessed whether climate sensitivity was different in warmer times, like the Pliocene, than in colder times, like the glacial cycles of the last 800,000 years.

Professor Eelco Rohling of The Australian National University in Canberra says: "We find that climate change in response to CO2 change in the warmer period was around half that of the colder period. We determine that this difference is driven by the growth and retreat of large continental ice sheets that are present in the cold ice-age climates; these ice sheets reflect a lot of sunlight and their growth consequently amplifies the impact of CO2 changes."

Professor Richard Pancost from the University of Bristol Cabot Institute, added: "When we account for the influence of the ice sheets, we confirm that the Earth's climate changed with a similar sensitivity to overall forcing during both warmer and colder climates."


Related Links
University of Southampton
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 DiggDigg RedditReddit GoogleGoogle

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

Plea for 'urgency' at UN climate talks
Geneva (AFP) Feb 8, 2015
UN climate negotiators gathered in Geneva were urged Sunday to show urgency and compromise in crafting a draft by next week for a global pact to be signed in December. "I ask you to work with efficiency and a sense of compromise," Manuel Pulgar-Vidal, Peru's environment minister and president of the negotiations told the opening session of the six-day talks. Pointing to scientific warnin ... read more

Service Module of Chinese Probe Enters Lunar Orbit

Service module of China's lunar orbiter enters 127-minute orbit

Chinese spacecraft to return to moon's orbit

Russian Company Proposes to Build Lunar Base

Meteorite may represent 'bulk background' of Mars' battered crust

Gully patterns document Martian climate cycles

The two faces of Mars

Several Drives This Week Put Opportunity Near Marathon Distance

Heady days for tech sector 15 years after bubble burst

NASA hails spending boost under Obama budget proposal

Mini Models Fire Up for SLS Base Heating Tests

Vega receives Spaceplane payload for Feb 11 suborbital mission

More Astronauts for China

China launches the FY-2 08 meteorological satellite successfully

China's Long March puts satellite in orbit on 200th launch

Countdown to China's new space programs begins

The Strange Way Fluids Slosh on the International Space Station

NASA's CATS Installed on ISS by Robotic Handoff

Roscosmos, NASA Still Planning on Sending Men Into Space

Russian Cargo Spacecraft to Supply ISS With Black Caviar

Soyuz Installed at Baikonur, Expected to Launch Wednesday

Russia launches British comms satellite into space

Iran Launches Satellite Into Space, First Since 2012

Moog Supports Delta 2 of SMAP satellite

Dawn ahead!

Habitable Evaporated Cores

Smaller Gas Giants Could Support Life

Will NASA's TESS Spacecraft Revolutionize Exoplanet Hunting?

Eyes In The Sky: Britain's GCHQ Sets Sights on Space

How ionic: Scaffolding is in charge of calcium carbonate crystals

Graphene edges can be tailor-made

Scientists 'bend' acoustic and elastic waves with new metamaterials

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.