[Arragonis]

Originally Posted by jamesqf

Yes, I understand that. The point I was trying to make is that their redating is (presumably, the original paper is behind a paywall) a matter of having obtained more accurate data. You imply that they simply juggle dates to get the desired results.

Apologies I misread it. The redating was explored here

Marcott, Shakun, Clark and Mix did not use the published dates for ocean cores, instead substituting their own dates

which goes on to look at the reasons and validity of the redating over several detailed posts. Some commenters there disagree with the negative analysis.

But even if the redating is valid the paper's conclusions are not those promoted by Climate Progress, something which several scientists have questioned.

For example original press release :

What that [temperature reconstruction] history shows, the researchers say, is that during the last 5,000 years, the Earth on average cooled about 1.3 degrees Fahrenheit--until the last 100 years, when it warmed about 1.3 degrees F.

But this is what the authors put out in their FAQ

Q: What do paleotemperature reconstructions show about the temperature of the last 100 years?

A: Our global paleotemperature reconstruction includes a so-called “uptick” in temperatures during the 20th-century. However, in the paper we make the point that this particular feature is of shorter duration than the inherent smoothing in our statistical averaging procedure, and that it is based on only a few available paleo-reconstructions of the type we used. Thus, the 20th century portion of our paleotemperature stack is not statistically robust, cannot be considered representative of global temperature changes, and therefore is not the basis of any of our conclusions.

So the 20th century scary uptick is not robust, and this graph :



should really look like this



which is a lot less scary. It was also the point I was trying to make about the resolution of reconstructions vs. instruments.

But as that would not follow the Think Progress narrative (doomed, we're doomed) they don't report that part or indeed any uncertainties of the science, and continue to push the original line.

I don't think the scientists involved did anything wrong, or at least not intentionally wrong, the PR was allowed to take over.