1.
the fig 6.10 chart you have posted - the brown/orange one - compares instrument temperatures alongside the uncertainty ranges ascribed to paleo data. You need to look very carefully to appreciate what you are being shown.
To explain that:
The larger medieval spike is only showing the edge of the standard error limits for only one of ten paleo reconstructions. And those paleo reconstructions are not individually and even collectively global. That is explained in the key and title of the chart. More on that later.
So you are relying on the very edge of the standard error, of the most extreme fraction of the available data, to form a view. You are comparing a statistically extreme boundary of a single very limited proxy set to the accuracy and global measure of the current instrument record.
The nature of the chart tends to lead to us to do that, but scientists are presenting complex information so you have to be very careful how you interpret what you are seeing and read the fine print to ensure you understand.
2.
the same chart is only for the Northern Hemisphere.
as I think you are aware, it is largely outside the northern hemisphere where it is considered that the medieval period was not warm.
So, again, the chart needs to be very carefully considered and it is easy to take a false impression relative to global instrument temps.
Which means that not only have you effectively relied on the outside of the error range of one proxy dataset, but you are looking at that for a proxy data set for (part of) the NH only.
3.
The Box 6.4 Fig 1 title comment makes these points explicitly, if somewhat too subtly. The Box 6.4 Fig 1 commentary points to the fact that proxy records demonstrate a wide range of temperatures for the Medieval period. Heterogenous, they say ...
A less understated presentation would be screaming those facts, saying proxy records are all over the place for the supposed medieval "warm" period, with many of them actually showing relative cold.
Scientists are oh so understated
4.
So you have largely relied on that chart, which I hope you will understand that you have misinterpreted, plus the Lindquist one, and have missed the significance of all the other evidence and discussion in the IPCC report
And that has led you to a different conclusion from the IPCC which based it's assessment on a much wider and complete consideration and analysis of the data.
Does that not ring some alarm bells.
It is fair to say you have inadvertently focused effectively on a cherry pick of the statistical edge of the hottest NH proxy. And if you looked closely at the Lindquist chart and commentary on it, you will find similar issues.
Based on that you have backed yourself against the IPCC ...
5.
In reaching your conclusion you also appear to have missed the additional point I made that models show that current warming is not natural and can only be ascribed to greenhouse gasses.
In addition - and introducing new info here not included in my initial post - there are known factors that contributed to the limited warming that proxy records pick up for the Medieval period.
https://www.newscientist.com/article/dn16892-natural-mechanism-for-medieval-warming-discovered/
https://www.skepticalscience.com/medieval-warm-period.htm
https://news.utexas.edu/2010/11/11/medieval-warm-period-not-so-random
So there is a scientific explanation for natural causes for what warming was seen in the medieval period, which natural causes do not apply today.
While models demonstrate that only greenhouse gas warming can explain current warming.
So you've missed all that from your assessment.
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I would hope that there is more than enough in the above for you to recognise that you need to re-examine your position.
And, I would suggest that in overlooking so much information- information that was deliberately put in front of you - you need to also examine if you are as free from biases as you believe you are.
The above, and more, was certainly enough for the IPCC to reach a totally different conclusion from the one you've reached.
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Now, I don't have all day to spend on this stuff, but I was prepared to go to this trouble because I think there is a degree of genuine interest and intention to find the truth on your part. But I am not going to promise to continue further with this discussion. I do have other things to do. And this sort of stuff takes time
bellcurve's and my original comments were that :
- you dismissed the considered views of 'authority' far too lightly
- you expressed opinions with very little supporting argument, against that authority
And subsequently your posts have shown a degree of bias or cognitive blindness that has led you to overlook key points. And I suspect you haven't appreciated the extent to which you've done that. We're all human.
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I agree that this forum is largely scattery and makes no overarching considered and structured argument. But then that's mainly because the denial camp bombards these threads with garbage and is quick to change the subject when pinned down with argument.
And because, imho, the very considered and structured science argument is already presented by the IPCC. Albeit not in easy to read blockbuster novel format.
No-one that I've seen posting here has the full package of time, patience, knowledge (and willingness/stupidity to head bang with idiots) to in some way paraphrase, present and defend that magnum opus of science work post by post.
Some of us just do our best just to point out the flaws in denial codswallop.