Winter and summer temperature anomalies 1500–2000 from the reconstruction5 are shown in black, instrumental data in red30 and climate-model simulations in green (HadCM3; ref. 8), magenta (NCAR-CSM1.4; ref. 9) and cyan (ECHO-G; ref. 7)
Sunny skies or stormy weather - monks wrote it in their diaries 500 years ago - Scotsman.com News
ANCIENT weather records, including details gleaned from monks' diaries, are helping Scottish scientists work out how and why European climates have changed over the past 500 years.
Researchers found the historic data, from the likes of weather station archives and harvest records, closely matched modern computer simulations of climate patterns over the past five centuries.
They say the fact the computer models were on target for the past suggests future predictions will be accurate, and forecast that greenhouse gas emissions will shape the climate in future in a "significant and visible" way.
Gabi Hegerl studies changes in climate extremes in climate model simulations and tries to detect them in observations.
Carts and horses come to mind.
UPDATE - as a wise monk points out in the comments the models are based on the data so that the data agrees with the models shouldn't be a surprise, and doesn't actually tell us very much.