RealClimate Looks at Latest Greenhouse Gas Data
by Michael Graham Richard, Gatineau, Canada on 11.27.05
Not long ago, we wrote about the new scientific research that shows that greenhouse gases are at their highest point in 650,000 years (with a strong progression in the past 50 years). Now, the scientists and climate experts at RealClimate have a post shining some light on the implications of the Antarctica findings, followed by a very interesting, and sometimes technical, discussion on the subject in the "comments" section. It will no doubt take a while to crunch all the new data and run new climate models, but this preliminary information is quite interesting and seems to confirm (once again) many theories.
This ice core extended the record of Antarctic climate back to maybe 800,000 years, and the first 650,000 years of ice have now been analysed for greenhouse gas concentrations saved in tiny bubbles. The records for CO2, CH4 and N2O both confirm the Vostok records that have been available for a few years now, and extend them over another 4 glacial-interglacial cycles. This is a landmark result and a strong testament to the almost heroic efforts in the field to bring back these samples from over 3km deep in the Antarctica ice. So what do these new data tell us, and where might they lead?"First of all, the results demonstrate clearly that the relationship between climate and CO2 that had been deduced from the Vostok core appears remarkably robust. This is despite a significant change in the patterns of glacial-interglacial changes prior to 400,000 years ago. The 'EPICA challenge' was laid down a few months ago for people working on carbon cycle models to predict whether this would be the case, and mostly the predictions were right on the mark. (Who says climate predictions can't be verified?). It should also go almost without saying that lingering doubts about the reproducibility of the ice core gas records should now be completely dispelled. That a number of different labs, looking at ice from different locations, extracted with different methods all give very similar answers, is a powerful indication that what they are measuring is real. Where there are problems (for instance in N2O in very dusty ice), those problems are clearly found and that data discarded.
For more go to: ::650,000 years of greenhouse gas concentrations
um.. if the industrial revolution was 100(aprox) years ago, what accounted for the growth in CO2 levels for the prior 649,000 years?
I think that they are making two points:
1) That natural events in the past 650,000 couldn't bring GHG higher than they are now;
2) That the exponential increase was in the past 50 years (we mentioned that in our other post on the subject). They don't say that the increase was over the last 650,000 equally.