Yet another paper - MWP warmer than current warming!

Seebergsee (Switzerland)
From CO2 Science (link)

A new peer reviewed paper published in Quaternary Science Reviews 41 (Link) is yet another nail in the MBH98 HockeyStick's coffin. The authors Larocque-Tobler et al found that the Medieval Warm Period - or as they refer to it - the 'Medieval Climate Anomaly' (MCA) was warmer than the temperatures in the  last century.


Determining if temperatures of the last century exceed natural variability necessitates the use of high-resolution paleo-reconstructions extending beyond the instrumental data (i.e. >150 years). Although syntheses using tree-ring, stalagmite, and borehole based reconstructions are available, biological proxies preserved in lake sediments have been neglected as a source of high-resolution information on climate change. Here, we present a decadal-scale mean July air temperature reconstruction covering the past millennium from varved Seebergsee, Switzerland. This reconstruction is compared to instrumental data at local, regional and European scales, to another high-resolution chironomid-inferred temperature reconstruction from Lake Silvaplana (Switzerland), to a composite of paleo-climate reconstructions from the Greater Alpine Region and to various millennial scale climate reconstructions from the northern hemisphere. When compared to local and regional instrumental records since ca 1760 AD significant (p < 0.01) relationships (rPearson > 0.5) are obtained, suggesting that chironomids accurately register the changes in temperature for the past ca 250 years. At European scale, the Seebergsee reconstruction correlates (rPearson = 0.40; p < 0.01) with instrumental and early instrumental data back to 1500 AD. On the millennial time scale, the chironomid reconstruction of Seebergsee provides a pattern of temperature changes mirrored by the chironomid reconstruction from Silvaplana (rPearson = 0.44; p < 0.01) and the Greater Alpine Region composite of reconstructions (rPearson = 0.40; p < 0.01). This includes warmer-than-the-last-century mean July air temperatures (+1.2 °C on average) during the end of the “Medieval Climate Anomaly” (MCA) and colder-than-the-last-century temperatures (−0.5 °C on average) during the “Little Ice Age”. Both chironomid reconstructions inferred a warming during the last decades, but this chironomid-inferred warming does not exceed the MCA temperatures. This result is not singular as many millennial temperature reconstructions in the northern Hemisphere do not show unprecedented warming of the last century at local/regional scale. However, the chironomid assemblages found in Seebergsee and Silvaplana since ca 1950 AD seem to be unique (i.e. they show unprecedented assemblage compositions) for the past 1000 years.

Larocque-Tobler, I., Stewart, M.M., Quinlan, R., Traschel, M., Kamenik, C. and Grosjean, M. 2012. A last millennium temperature reconstruction using chironomids preserved in sediments of anoxic Seebergsee (Switzerland): consensus at local, regional and Central European scales. Quaternary Science Reviews 41: 49-56.  

What was learned
The six scientists' work revealed that the peak warmth of the MCA just prior to AD 1200 was approximately 0.9°C greater than the peak warmth near the end of their record, as best we can determine from the graph of their data.

What it means
As more and more palaeo-temperature data are acquired, the IPCC-endorsed "hockeystick" temperature record of Mann et al. (1999) - which gives little indication of the existence of the MCA and shows recent temperatures towering over those of that earlier time period - is fading slowly into the night, as it is repudiated by ever more real-world data. And it's not just the most recent data of Larocque-Tobler et al. that refute the IPCC's view of this matter; for the group of six says that their newest temperature history is "mirrored by the chironomid reconstruction from Silvaplana and the Greater Alpine Region composite of reconstructions." And they add that "several other reconstructions from the Northern Hemisphere also show [recent] warm inferred temperatures that were not as warm as the MCA."

CO2 Science adds:
In addition, and it's a big addition, we note that many more palaeoclimatic studies from all around the world - which are described and have their results tabulated in our Medieval Warm Period Project - likewise testify to the greater-than-current peak-warmth of the MCA.