What does the Vostok ice core tell us? | …and Then There's Physics
Ice-core records show that climate changes in the past have been large, Accuracy can be assessed by comparison to the chemically identified fallout of Most ice lacks sufficient appropriate materials to allow precise radiometric dating, but . of events that may be correlative to nearly all of the Greenland events (31). Ice cores can be dated using counting of annual layers in their uppermost layers. Dating the ice becomes harder Usually multiple methods are used to improve accuracy. Common global stratigraphic View all posts by Bethan Davies →. Eric Steig (who is one of the PIs of the WAIS Divide Ice Core) has .. “Global temperature” is a complex mix of all these signals and is not directly .. As noted by a reviewer, Pedro et al aligned their dates using CH4 for.
Ice-core evidence of abrupt climate changes
Posted on June 18, by Temperature CO2 and CH4. This post has apparently had reads, is probably one of the most read texts on the subject, and yet, according to this postthe Climate Science community continues to ignore the fairly profound implications of what the data actually shows. These natural geochemical cycles makes it inevitable that CO2 and CH4 will correlate with temperature.
It is therefore totally invalid to use this relationship as evidence for CO2 forcing of climate, especially since during the onset of glaciations, there is no correlation at all.
Ice-core evidence of abrupt climate changes
It simply responded to bio-geochemical process caused by changing temperature and ice cover. I left a couple of comments, but only one has appeared, so I thought I would quickly write this post. Firstly, this is data from a single site Vostok.
Even though greenhouse gases may be well-mixed, the temperature is not. Maybe more importantly, though, what the data indicates is not really all that surprising.
The inconvenient truth about the Ice core Carbon Dioxide Temperature Correlations
Consistent dating for Antarctic and Greenland ice cores. Quaternary Science Reviews 29, Mulvaney R, et al. Recent Antarctic Peninsula warming relative to Holocene climate and ice-shelf history.
Nature Vinther BM, et al. A synchronized dating of three Greenland ice cores throughout the Holocene. Journal of Geophysical Research: I wrote and developed the AntarcticGlaciers. Read more about me at www. In round figures say, to the nearest 10, yearshow far back can you use separate layers to date an ice core? The bottom line is that the equilibrium is quite complicated to calculate. The change in the amount of atmospheric CO2 is about 80 ppm. The main evidence proving that CO2 does not control the climate, but at most can play a second fiddle by just amplifying the variations already present, is that of lags.
In all cases where there is a good enough resolution, one finds that the CO2 lags behind the temperature by typically several hundred to a thousand years. Namely, the basic climate driver which controls the temperature cannot be that of CO2.
That driver, whatever it is, affects the climate equilibrium, and the temperature changes accordingly. Once the oceans adjust on time scale of decades to centuriesthe CO2 equilibrium changes as well. Note that I write "almost anything", because it turns out that the CO2 temperature correlation can be used to say at least one thing about the temperature sensitivity to CO2 variations, as can be seen in the box below.
It is interesting to note that the IPCC scientific report e. Instead of pointing it out, they write that in some cases e. This is of course chaff to cover the fact that when CO2 and temperature are measured with the same cores, or when carefully comparing different cores, a lag of typically several hundred years is found to be present, if the quality and resolution permit. Such an example is found in the figure below.
How are ice cores dated? - negeriku.info
There are many examples of studies finding lags, a few examples include: Science, volp. Science vol, find that the start of the CO2 increase in the beginning of the last interglacial lagged the start of the temperature increase by years.
Clearly, the correlation and lags unequivocally demonstrate that the temperature drives changes in the atmospheric CO2 content. The same correlations, however cannot be used to say anything about the temperature's sensitivity to variations in the CO2.
I am sure there is some effect in that direction, but to empirically demonstrate it, one needs a correlation between the temperature and CO2 variations, which do not originate from temperature variations.
The only temperature independent CO2 variations I know of are those of anthropogenic sources, i.