Reference
Millet, L., Arnaud, F., Heiri, O., Magny, M., Verneaux, V. and Desmet, M. 2009. Late-Holocene summer temperature reconstruction from chironomid assemblages of Lake Anterne, northern French Alps. The Holocene 19: 317-328.
Description
Millet et al. developed "a new chironomid-based temperature record from Lake Anterne (northern French Alps) covering the past two millennia" with the help of a mean July air temperature transfer-function derived from the surface sediments of 114 lakes in northern Switzerland. Although the reconstructed data indicate the MWP was warmer than the CWP, the data were only considered valid up to the start of the 20th century. Subsequent to that time, human-induced environmental changes (fish introduction) in the lake likely contaminated the chironomid reconstruction, making a quantitative and/or qualitative comparison of MWP vs. CWP temperatures problematic. Given these potential inaccuracies, we have decided to classify this reconstruction as a Level 3 study and to only utilize it in further clarifying the time interval of the MWP, which the authors list as between AD 680 and 1350.