A new study from James Hansen University chooses to use proxy data, while ignoring the thermometer data.

Summers on the Norwegian archipelago of Svalbard are now warmer than at any other time in the last 1,800 years, including during medieval times when parts of the northern hemisphere were as hot as, or hotter, than today, according to a new study in the journal Geology.

Researchers produced the 1,800 year climate record by analyzing levels of unsaturated fats in algae buried in the sediments of Kongressvatnet lake, in western Svalbard.

High-Arctic Heat Tops 1,800-Year High, Says Study | Lamont-Doherty Earth Observatory

This is the reverse of Michael Mann’s approach. Mann threw out proxy data which he didn’t like, and replaced it with Hansen’s adjusted thermometer data. In this case, the researchers ignored the thermometer data, and replaced it with proxy data.