Vostok ice core, Antarctica

As this blog is titled CO₂ and global temperatures – past, present and future, I felt it was time to dig a little into some academic papers.  Firstly looking at a selection of papers in relation to past CO₂ and temperature.  There is no particular structure to this.  I have picked papers that I found interesting from a number of journals.  The first of which is a paper published in Nature way back in June 1999.  The paper by Petit et al (1999) is titled “Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica”.  I don’t mind admitting that I have a real interest in Antarctica and find the information gained from ice cores fascinating.  As this is a blog I shall forego too much detail and instead summaries the papers basic points to give you a general over view. 
 

Image illustrating the location of the Vostok Core Site.  http://cdiac.esd.ornl.gov/trends/co2/graphics/antartica_ice_core_stations.jpg

Petit et al (1999) open by explaining a little about the late Quaternary period which was the past one million years and how the period saw a number of large glacial-interglacial cycles of approximately 100,000 years.  They then moves on to ice cores themselves, informing the reader that ice cores can offer information of palaeoclimate series such as temperature and aerosol fluxes and even past atmospheric trace-gas composition due to entrapped air inclusions.  Petit et al (1999) state that there is a strong correlation between Antarctic temperatures, CO₂ and CH₄ concentration in the atmosphere.  They go on to state that “This discovery suggests that greenhouse gases are important as amplifiers of the initial orbital forcing and may have significantly contributed to the glacial–interglacial changes. The Vostok ice cores were also used to infer an empirical estimate of the sensitivity of global climate to future anthropogenic increases of greenhouse gas concentrations”. 



Image of the Vostok Ice Core.  http://i.telegraph.co.uk/multimedia/archive/02133/ice-core_2133381i.jpg

Petit et al (1999) conclude that as a result of the information gained from the Vostok ice core it can be said that for the past 420 kyr our planets climate has undergone changes to its state that fall within stable bounds.  That is to say that for the last four glacial terminations a pattern of temperature, CO₂ and CH₄ rises are recorded in the ice core.  They conclude by stating that the results they obtained “support the idea that greenhouse gases have contributed significantly to the glacial–interglacial change”. 

 

Reference
Petit, J.R. Jouzel, J. Raynaud, D. Barkov, N.I. Barnola, J.M. Basile, I. Bender, M. Chappellaz, J. Davisk, M. Delaygue, G. Delmotte,M. Kotlyakov, V.M. Legrand, M. Lipenkov, V.Y. Lorius, C. Pe´ pin, L. Ritz, C. Saltzmank, E. Stievenard, M. (1999). Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica. Nature. 399, pp.429 - 436.