More about the present... I've found a nicer example about the role of the ocean to the overall global warming. You can see how the total heat increase of the complete climate system (ocean + land + atmosphere) is unstoppable. The "stabilization" in heat content that we see in land temperatures (during the last 15 years) are fairly insignificant in the broader picture, and is offset by the much larger increase in heat content of the (deeper) oceans.
http://www.sciencedirect.com/science/article/pii/S0375960112010389
or this one with an additional discussion:
http://www.skepticalscience.com/nuccitelli-et-al-2012.html
And this is the influence of CO2:
http://www.cfa.harvard.edu/hitran//
Check the documentation, the paper describing the 2012 edition, figure 4.
it is easier to understand the CO2 absorption process from a laboratory, then from the Antarctic. Because in the lab you actually observe a single physical process.
People who claim that CO2 is not an important greenhouse gas, go against such lab measurements...
I found this interesting (ongoing) laboratory experiment which investigates how clouds affect climate.
http://e360.yale.edu/feature/jasper_kirkby_cern_creates_cloud_in_lab_to_understand_climat_change/2601/
http://www.theverge.com/2013/10/11/4827762/cern-cloud-experiment-sheds-doubt-on-climate-skeptic-theory
(and the original site:)
http://home.web.cern.ch/about/experiments/cloud
http://press.web.cern.ch/press-releases/2013/10/cerns-cloud-experiment-shines-new-light-climate-change
Are there significant differences between CO2 concentration over the poles and CO2 concentration over the rest of the planet currently? If that is the case, one could at least argue that the ice cores may not be representational, but it's the 'very likely' bit... considering that we've only had one orgy of fossil fuel burning in our history (that we know of) and that current geographic variations, if they exist and are significant, may not be representational of pre-industrial geographic variations. (I think NASA has a satellite studying geographic variations, either active or planned.)
No I don't think there is much difference... but you ignore the other side of the coin: is the temperature record at the Antarctic representative of that of the rest of the world ?
Oh wait, I've found this image:
http://www2.hawaii.edu/~robi2448/CO2_distro_map.html
And it shows a lot of CO2 variability on the earth.
But I don't think it matters much, because what's of interest is the change in CO2 with time at any one spot on the earth, not the actual CO2 value.
I've found this: another single-point measurement (from a large impact crater no less), but this time from the Arctic.
http://www.scientificamerican.com/article.cfm?id=ice-free-arctic-in-pliocene-last-time-co2-levels-above-400ppm
Unfortunately the description of the results is qualitative, there is no time line, such a shame ! This is a little bit more elaborate with some nice pictures of the impact crater:
http://www.skepticalscience.com/print.php?n=2016
This elaborates a bit more on "exceptional warm periods".
http://www.nsf.gov/news/news_summ.jsp?cntn_id=124565
This is also about a warm period but this time in Greenland. It draws an analogy with the 2012 summer melting across the Greenland ice sheet.
http://www.nature.com/nature/journal/v493/n7433/full/nature11789.html
And this is about the ocean circulation (maybe it was referenced before but I'll just do it again):
http://www.sciencedaily.com/releases/2012/03/120329142020.htm
It's a nice theory about how levels of CO2 are controlled by the ocean (and not by temperature...).
A little more on the Antarctic and ice cores. This article shows a graph of CO2 with error margins:
http://www.chem.hope.edu/~polik/warming/IceCore/IceCore2.html
The following is a more in-depth by Shakun (the one who did a more globalized study on the ice ages). It starts with a few irrelevant but very instructive examples of data sets where one can measure a temperature fluctuation at 1 point that goes against common sense, if one would interpret the result without taking local effects into account. It shows how the examples make more sense when more data are used from different locations, to give an average where local effects are less important.
https://www2.bc.edu/jeremy-shakun/FAQ.html
An article like this is great stuff.
Compare that to journalistic bullshit like this (I picked it at random - it's just one of dozens of nonsense articles that I come across whenever I search for articles on the internet):
http://www.forbes.com/sites/peterferrara/2013/05/26/to-the-horror-of-global-warming-alarmists-global-cooling-is-here/
The writer just assumes the sun is all-important and he thinks that a solar minimum is some incredible event, associated with a little ice age no less! Of course he ignores a lot of other evidence. Also I doubt the journalist ever checked on the numbers and the contribution of the sun cycle on global temperatures, which are at most 0.7 degrees between the maximum and minimum (associated with a 0.4% change in intensity).
I think that even if the sun would "cool down" it wouldn't be anything dramatic. It would imply the sun becomes calmer and that there will be fewer maxima. This would only amount to a cooling of about 0.2% (or about 0.4 degrees on a global average ; probably some more on high latitudes).
Now if we were are a tipping point between an ice-age or not, then it would've been important. But that isn't the case, according to most scientists we are facing a long term warming of 2 to 6 degrees in the next century due to the build-up of CO2. Whether the sun get a little bit cooler or not, makes little difference.
What scares me a little about such articles is, that a journalist with good writing skills manages to write a convincing story... which is just based on the assumption that a solar cool-down is something that will dwarf everything else... but he acts like he knows that it is the case and that it's not an assumption, but a fact.
