Hi esin,
Those are really pretty graphs. Pity they don't necessarily have science to back them up. The temperature ranges are guesses, and imho, bad ones at that. The amount of carbon dioxide is also questionable although the variation over time is not.
If you have been reading the posts for a while, you will know I have a real aversion for science presented as graphs without the underlying data being accessible or referred to. In this case, I have a pretty good idea where that data came from. This is the stuff of text books, not accurate scientific argument.
I must say the graphs are a pretty good argument against global warming due to increased CO2 but that is beside the point. Graphs showing summarised data without a reference are BAD regardless whether they support what I'm arguing or not.
That's not to say anything negative about you by the way, only that there should have been link to the data or at least the study that came up with these figures. Since this is an area of interest I have a fair idea where these figures came from and could also produce a graph but looking dramatically different.
Christopher Scotese, while a paleogeorgrapher with terrific credentials, has been studying plate tectonics and how best to present these in a teaching environment for the last 25 years. The climatic side of this is a minor part of what he has been doing.
Christopher Stotese, and this is no critiscim of him at all - the stuff he does is really terrific - is a "big picture" person.
The argument I would have is that it is just impossible to tell from the study of rocks, what the world's climate was in more than generalist terms. You can say it was hot or cold but not what temperatures. So actual temperatures become a guess. In many parts of geologic time, there is not sufficient samples to actually even say what happened would wide and so it is extrapolated from what is available.
I really don't know what you were trying to argue but the quote at the beginning of your post suggests you were trying to demonstrate that plate movements always cause Ice Ages. It is the always I would not be so quick to agree with, otherwise I'd agree. I'm not sure the graphs provide supports the argument simply because of its time scale.
As to the CO2 levels, these are even worse guesses, but don't take my word for it. Read an article by RA Berner, the person to which the CO2 on the graph is attributed to. (
http://stephenschneider.stanford.edu/Publications/PDF_Papers/CrowleyBernerScience01.pdf)
It really is fun to look at just how figures are created by anyone arguing about climate, especially as it relates to todays micro changes in world climate. Climate of 55 million years ago is relevant to the study of dinosaur deaths, the development of birds, flora and a whole heap of other things but relevant to whether there is global warming? Huh! The methodology of how the gross climate models are developed are actually much worse than those for global warming models. But then again, they don't need to be all that accurate, trends and major cycles are what is important.
Back to my very orginal argument. GIGO!
Undelying data for any global climate model cannot simply be accepted because someone has a PhD, a professorship or anything else. If you truly are interested in the study to which the model refers, in order to rank the model into degrees of accuracy even if only for your personal satisfaction, just how the data was used and how it was obtained is important. If the model is being used to support the ban on greenhouse gases then I would suggest the data HAS to be closely scrutinised.
Richard
