Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Carbon cycling was much smaller during last ice age than in today's climate

21.11.2011
Atmospheric carbon dioxide (CO2) is one of the most important greenhouse gases and the increase of its abundance in the atmosphere by fossil fuel burning is the main cause of future global warming.

In past times, during the transition between an ice age and a warm period, atmospheric CO2 concentrations changed by some 100 parts per million (ppm) – from an ice age value of 180 ppm to about 280 ppm during warm periods.

Scientists can reconstruct these changes in the atmospheric carbon stock using direct measurements of atmospheric CO2 trapped in air bubbles in the depth of Antarctica's ice sheets. However explaining the cause of these 100ppm changes in atmospheric CO2 concentrations between glacial and interglacial climate states – as well as estimating the carbon stored on land and in the ocean – is far more difficult.

The researchers, led by Dr Philippe Ciais of the Laboratoire des Sciences du Climat et l'Environnement near Paris, ingeniously combined measurements of isotopes of atmospheric oxygen (18O) and carbon (13C) in marine sediments and ice cores with results from dynamic global vegetation models, the latter being driven by estimates of glacial climate using climate models.

Dr Marko Scholze of the University of Bristol's School of Earth Sciences, co-author on the paper said: "The difference between glacial and pre-industrial carbon stored in the terrestrial biosphere is only about 330 petagrams of carbon, which is much smaller than previously thought. The uptake of carbon by vegetation and soil, that is the terrestrial productivity during the ice age, was only about 40 petagrams of carbon per year and thus much smaller: roughly one third of present-day terrestrial productivity and roughly half of pre-industrial productivity."

From these results, the authors conclude that the cycling of carbon in the terrestrial biosphere – that is, the time between uptake by photosynthesis and release by decomposition of dead plant material – must have been much smaller than in the current, warmer climate.

Furthermore there must have been a much larger size of non-decomposable carbon on land during the Last Glacial Maximum (the period in the Earth's history when ice sheets were at their maximum extension, between 26,500 and 19,000 years ago).

The authors suggest that this inert carbon should have been buried in the permanently frozen soils and large amounts of peat of the northern tundra regions.

Paper

'Large inert carbon pool in the terrestrial biosphere during the Last Glacial Maximum' by P. Ciais, A. Tagliabue, M. Cuntz, L. Bopp, M. Scholze, G. Hoffmann, A. Lourantou, S. P. Harrison, I. C. Prentice, D. I. Kelley, C. Koven and S. L. Piao in Nature Geoscience

Hannah Johnson | EurekAlert!
Further information:
http://www.bristol.ac.uk

More articles from Earth Sciences:

nachricht Impacts of mass coral die-off on Indian Ocean reefs revealed
21.02.2017 | University of Exeter

nachricht How much biomass grows in the savannah?
16.02.2017 | Friedrich-Schiller-Universität Jena

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Positrons as a new tool for lithium ion battery research: Holes in the electrode

22.02.2017 | Power and Electrical Engineering

New insights into the information processing of motor neurons

22.02.2017 | Life Sciences

Healthy Hiking in Smart Socks

22.02.2017 | Innovative Products

VideoLinks
B2B-VideoLinks
More VideoLinks >>>