The article abstract is as follows:
The paper itself is no doubt more informative - I'll see if I have access to it somehow. Thanks for the reference!
-Jester
Afterthought: Found the paper - most of it is far over my head. The major issues appear to be understanding the contribution of land use, and the uncertainties in the data making any result highly dependent on the specific data and methods used, and not robust across various analyses.
Edit: Discussion now up at Realclimate, links over there.
Quote:Several recent studies have highlighted the possibility that the oceans and terrestrial ecosystems have started loosing part of their ability to sequester a large proportion of the anthropogenic CO2 emissions. This is an important claim, because so far only about 40% of those emissions have stayed in the atmosphere, which has prevented additional climate change. This study re-examines the available atmospheric CO2 and emissions data including their uncertainties. It is shown that with those uncertainties, the trend in the airborne fraction since 1850 has been 0.7 ± 1.4% per decade, i.e. close to and not significantly different from zero. The analysis further shows that the statistical model of a constant airborne fraction agrees best with the available data if emissions from land use change are scaled down to 82% or less of their original estimates. Despite the predictions of coupled climate-carbon cycle models, no trend in the airborne fraction can be found.I'd have to read the paper to get more than a vague hint of what it actually demonstrates, but there are at least a couple things that pop out at me. First, the error bars are huge - plus or minus 1.4% per decade means the range is anywhere from an 11% decrease to a 34% increase, roughly speaking. Second, if you start your analysis in 1850, when emissions were a tiny fraction of what they are now, I suspect that would give you a "decadal average" that is very small, for obvious reasons - the later (high pollution, CO2 heavy ocean) decades are washed out by earlier (low pollution, CO2 light ocean) ones. The article, though not the abstract, suggests they examine this possibility in the paper. Third, the results are positive, not zero. Even at 0.7% per decade, over the 16 decades between then and now, that's about an 11% increase, which is not trivial. If we intend to continue polluting, I'm not sure even that slow rate would be acceptable.
The paper itself is no doubt more informative - I'll see if I have access to it somehow. Thanks for the reference!
-Jester
Afterthought: Found the paper - most of it is far over my head. The major issues appear to be understanding the contribution of land use, and the uncertainties in the data making any result highly dependent on the specific data and methods used, and not robust across various analyses.
Edit: Discussion now up at Realclimate, links over there.