Mot: ”Mitä arvioisit, kuinka paljon lämpimämpää oli tuolloin keskiajalla Suomessa kuin on nyt?
[Mot: What would you estimate, how much warmer than the present it was during the medieval times in Finland?]

Ojala: ”Sitä on näiden perusteella aika vaikea täsmällisesti sanoa. mutta puhutaan tommosesta puolesta asteesta, jopa asteesta erilaisten eurooppalaisten tutkimusten valossa”.
[Ojala: In the light of these results, it is very hard to tell exactly, but we talk about something like half a degree, even one degree in the light of various European research results.]

From the downloadable PDF at your link, I would remark a couple of sentences:

(Pg 22)

“The most distinctive climate period in the whole sediment sequence is the Medieval Warm Period in AD 980-1250″

(Pg 24)

“Since the early 18th century, the sedimentation has clearly been affected by increased human impact and therefore not useful for paleoclimate research”.

Yet Mann manages to use it to prove AGW…

I can’t believe it… Mann manages to bury his standards deeper and deeper, again and again. He should be in the Guiness book. This is just hilarious.

I’m sure it is just a mistake by Mann. But mistakes like this prove that whenever they get the “right” answer, no further research or data verification is performed. This way, errors can only bias any study in the desired direction. Bad science.

Mann’s flipping of the data is both humorous and illuminating. Yes, he used the data upside down (Upside-Down Mann) as a paleoclimate proxy based on a spurious correlation between increased sediments directly attributable to farming and a supposed teleconnection to world temperature.

All 4 Kortajarvi series are used incorrectly.

After reading the Tiljander paper, it’s clear that the measurement of the amount of minerals deposited annually in the lake sedimentation (designated as LS by Tiljander) should be inverted if it is going to be used as a temperature proxy (which at one point in the paper Tiljander seems to caution against doing, suggesting instead that hydrology rather than temperature is indicated). According to the authors, in years where the temperature is colder, more snow falls in the winter and consequently the spring thaw brings a larger amount of erosion from the melting snow — depositing more minerals in the lake bottom.

This is in contrast to the measurement of the organic matter in the sedimentation (designated as DS by Tiljander). Again, according to the paper, in years where the temperature is warmer, more organic matter is deposited in the lake bottom. (Of course, the authors also point out that given the introduction of anthropogenic factors in recent times disturbing the natural deposition of sediment in the lake, neither of these relationships really holds true for the last two centuries)

Yet the proxy series used by Mann (Lightsum — proxy #1061) corresponding to the measurement of the minerals does not seem to be inverted. It appears to be used in the same fashion as the series for measurement of the organic matter (Darksum — proxy #1062). This seems like such an elementary mistake that I’m sure it must be me that is confused, and not Mr. Mann. Perhaps the Lightsum series was inverted by Mr. Mann without any clear notation?

There is practically no permafrost in Finland today and probably hasn’t been since the last glaciation. The exception is “palsar”, mounds of permanently frozen peat that occur locally in bogs in northernmost Finland. And while the southern limit of permafrost is very sensitive to climatic change, the deep permafrost in Northern Siberia is more durable than most people think. During the previous interglacial (which lasted for 10,000 years) temperatures were as much as 10 degrees higher than today on the Taimyr peninsula, and even so some permafrost survived (and no large CH4 outgassing occurred).