Feeds

Ice age end was accelerated by CO2

Core study fingers culprit before  'big melt', not after

Top three mobile application threats

A new global study of ice core samples and underwater sediment suggests that rising atmospheric CO2 preceded the ending of the last Ice Age – not the other way around.

One of the favourite rhetorical devices of the climate change denier is to invert cause-and-effect – in other words, the carbon rise around the end of the last Ice Age happened as a result of the warming, not the other way around.

The latest study, published in Nature, could help put paid to this: in most of the 80 sites from which samples were taken, the scientists say, it’s clear that rising CO2 predated the “big melt”.

Over a period of 7,000 years, the scientists say, the atmospheric concentration of CO2 rose from 180 parts per million to 260 ppm. While the initial cause of the end of the Ice Age was a change in the “wobble” of Earth’s axis, the researchers believe the process was then accelerated by the CO2, possibly released from the warmer oceans.

As Christian Science Monitor reports, the only place in which the current study finds CO2 rises followed warming was in Antarctica: elsewhere, the rising carbon precedes accelerating warming.

As noted in the abstract, that difference can be associated with ocean currents: “Differences between the respective temperature changes of the Northern Hemisphere and Southern Hemisphere parallel variations in the strength of the Atlantic meridional overturning circulation recorded in marine sediments.”

“An antiphased hemispheric temperature response to ocean circulation changes superimposed on globally in-phase warming driven by increasing CO2 concentrations is an explanation for much of the temperature change at the end of the most recent ice age,” the abstract states.

It’s worth noting that the 260 ppm reached at the end of the Ice Age – sufficient to “deglaciate” huge amounts of the world – is far below today’s figure, which is closing in on 400 ppm. Lead author of the study, Jeremy Shakun, says we’re likely to end up carrying a further 100 ppm by the end of the century.

Shakun, of Oregon State University, collaborated with researchers from Harvard University and other institutions in America, China and France to conduct the study. ®

High performance access to file storage

More from The Register

next story
KILLER SPONGES menacing California coastline
Surfers are safe, crustaceans less so
Opportunity selfie: Martian winds have given the spunky ol' rover a spring cleaning
Power levels up 70 per cent as the rover keeps on truckin'
LOHAN and the amazing technicolor spaceplane
Our Vulture 2 livery is wrapped, and it's les noix du mutt
Liftoff! SpaceX Falcon 9 lifts Dragon on third resupply mission to ISS
SpaceX snaps smartly into one-second launch window
KILLER ROBOTS, DNA TAMPERING and PEEPING CYBORGS: the future looks bright!
Americans optimistic about technology despite being afraid of EVERYTHING
R.I.P. LADEE: Probe smashes into lunar surface at 3,600mph
Swan dive signs off successful science mission
Discovery time for 200m WONDER MATERIALS shaved from 4 MILLENNIA... to 4 years
Alloy, Alloy: Boffins in speed-classification breakthrough
prev story

Whitepapers

SANS - Survey on application security programs
In this whitepaper learn about the state of application security programs and practices of 488 surveyed respondents, and discover how mature and effective these programs are.
Combat fraud and increase customer satisfaction
Based on their experience using HP ArcSight Enterprise Security Manager for IT security operations, Finansbank moved to HP ArcSight ESM for fraud management.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Top three mobile application threats
Learn about three of the top mobile application security threats facing businesses today and recommendations on how to mitigate the risk.
3 Big data security analytics techniques
Applying these Big Data security analytics techniques can help you make your business safer by detecting attacks early, before significant damage is done.