The European Tribune is a forum for thoughtful dialogue of European and international issues. You are invited to post comments and your own articles.
Please REGISTER to post.
Not meaningfully, according to
URS SIEGENTHALER, ERIC MONNIN, KENJI KAWAMURA, RENATO SPAHNI, JAKOB SCHWANDER, BERNHARD STAUFFER, THOMAS F. STOCKER, JEAN-MARC BARNOLA, HUBERTUS FISCHER (2005)
Supporting evidence from the EPICA Dronning Maud Land ice core for atmospheric CO2 changes during the past millennium
Tellus B 57 (1), 51-57.
The most direct method of investigating past variations of the atmospheric CO2 concentration before 1958, when continuous direct atmospheric CO2 measurements started, is the analysis of air extracted from suitable ice cores.
The abstract continues:
Here we present a new detailed CO2 record from the Dronning Maud Land (DML) ice core, drilled in the framework of the European Project for Ice Coring in Antarctica (EPICA) and some new measurements on a previously drilled ice core from the South Pole. The DML CO2 record shows an increase from about 278 to 282 parts per million by volume (ppmv) between ad 1000 and ad 1200 and a fairly continuous decrease to a mean value of about 277 ppmv around ad 1700. While the new South Pole measurements agree well with DML at the minimum at ad 1700 they are on average about 2 ppmv lower during the period ad 1000-1500. Published measurements from the coastal high-accumulation site Law Dome are considered as very reliable because of the reproducibility of the measurements, high temporal resolution and an accurate time scale. Other Antarctic ice cores could not, or only partly, reproduce the pre-industrial measurements from Law Dome. A comparison of the trends of DML and Law Dome shows a general agreement. However we should be able to rule out co-variations caused by the same artefact. Two possible effects are discussed, first production of CO2 by chemical reactions and second diffusion of dissolved air through the ice matrix into the bubbles. While the first effect cannot be totally excluded, comparison of the Law Dome and DML record shows that dissolved air diffusing to bubbles cannot be responsible for the pre-industrial variation. Therefore, the new record is not a proof of the Law Dome results but the first very strong support from an ice core of the Antarctic plateau.
by Frank Schnittger - Mar 16 38 comments
by Oui - Mar 14 22 comments
by ARGeezer - Mar 7 26 comments
by Frank Schnittger - Mar 8 16 comments
by Oui - Mar 9 3 comments
by Frank Schnittger - Feb 28 112 comments
by Bernard - Feb 24 6 comments
by Oui - Mar 3 4 comments
by Oui - Mar 17
by Oui - Mar 171 comment
by Frank Schnittger - Mar 1638 comments
by Oui - Mar 15
by Oui - Mar 1422 comments
by Oui - Mar 93 comments
by Oui - Mar 91 comment
by Frank Schnittger - Mar 816 comments
by ARGeezer - Mar 726 comments
by Oui - Mar 5
by Oui - Mar 34 comments
by Frank Schnittger - Feb 28112 comments
by Bernard - Feb 246 comments
by Oui - Feb 23
by Frank Schnittger - Feb 2171 comments
by Cat - Feb 1830 comments
by Oui - Feb 179 comments
by Oui - Feb 87 comments
by Frank Schnittger - Jan 2816 comments