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There are a number of hypotheses in the paper. The most explicit one is about measured climate anomalies correlating with LIA or MWP. As you point out, the anomaly correlation can be cooling OR dryness OR wetness in the LIA and warming OR dryness OR wetness in the MWP. But the paper also proposes hypotheses for a shift from wet to dry or from dry to wet correlating with cooling or warming. The text had some explanations for these occurances but the tables only had the occurances which could admittedly point either way. But the conclusions are separate, that the 20th century is not the warmest, nor the most climatically extreme.

In my opinion Both conclusions are supported by the data. Clearly the climatic extreme question is resolved beyond a doubt, there are far fewer in the 20th century than in the previous 11 centuries. The warming and cooling is supported less fully, but still quite generally. The difficulty of correlating the proxies to actual warming and cooling is discussed as are many possible local effects that correlate wetness or drying to cooling or warming. In many cases warmer meant wetter and cooler meant drier as explained by plausible local phenomena. There were exceptions that were also fairly well explained.

I would say the two conclusions are hard to separate because of the relationship of both types of measurements (temp and precip) to the proxies. But the implication that dryness and wetness correlates with temperature changes is well supported. And so then is the conclusion that the 20th century is not extreme in either warming or cooling. As for warming in MWP and cooling in LIA, they seem to be well supported although not as clearly as their being extremes of dryness or wetness. The proxies clearly indicate that, but not as clearly the temperature. The temperature conclusions are obvious for Europe and N. America, but less for the rest of the world. But there's little evidence for the rest of the world that the LIA was warm or that the MWP was cool anywhere.

Humm, so what makes a drought in a region of the world indicate a warming during the MWP while an identical drought in the identical place indicates a cooling in the LIA? The paper does comment on the shift from wet to dry but does not offer any reason at to why it is true and in fact uses what ever data is handy to support the conclusions regardless of whether it is wet or dry.

For example to support his position he uses the following. In central Argentina, he describes the climate as more humid with increased lake sizes during the MWP. For the North Atlantic he describes the effects of the LIA as being unusually cold and wet. And in Europe, he describes flooding during the transition period between the MWP and the LIA. So increase in wetness can mean the Medieval Warm Period, the Little Ice Age and even the time in between!!! If you want to look at dry conditions, in China extremely dry conditions prevailed during the 16th and 17th centuries. In South America he states that the Patagonia region was abnormally dry during the MWP.

In most cases he presents them with no indication of why they support this particular conclusion. However when he does present a reason, it is pulled out of a hat because it would seem to match his data without any thought given to other possibilities or reasons. For example in discussing the North American west coast he notes that California, the NW Great Basin, and the northern Rocky Mountains/Great Plains experienced drought, then a period of wet, then back to a period of dry. You might think that this would cause problems for his wet = warm hypothesis, but no, the changes were caused by “the contraction and subsequent expansion of the circumpolar vortex.” If there is any justification for this besides the fact that it fits his theory, I can’t find it!

The very best that this paper can do is to show that there were weather anomalies at certain times. He does present some temperature information, but even this is botched. He used the same deMenocal and Keigwin papers as discussed before. Both of these are presented as evidence for the LIA and MWP when in fact what they show was a change in ocean circulation. Now if you want to argue that the change in ocean circulation was caused by climatic conditions consistent with the LIA and MWP, then that is a different and better argument, but he does not argue this and they are taken as temperature proxies.

So, contrary to you I feel that the paper is not well documented and not well supported. On the other hand it does have a heck of a reference section which I know impresses some.

Good night.
Yelling.