Details of weather records taken from monks’ diaries are helping scientists verify Europe’s climate over 500 years.
Researchers hope the study will help improve climate forecasts.
Scientists compared data from historic sources, such as weather station archives and harvest records.
They found the records match closely to computer simulations of climate patterns over the past 500 years, which were created using contemporary data.
The simulated data took account of minor influences on the weather. These include volcanic activity, variations in the sun’s temperature and - more recently - an increase in greenhouse gases.
Scientists say that because the two sets of data match, these additional factors affecting temperature are more important for explaining past climate in Europe than was previously realised.
Scientists say the study suggests that present-day greenhouse gas emissions may play an important role in shaping future European climate.
By quantifying the effect of these factors on the temperature in different seasons, the findings help to evaluate how effective climate models are, and will lead to more accurate predictions of climate change.
The study, carried out by the University of Edinburgh in collaboration with the Justus-Liebig University of Giessen, and the Universities of Bern and Madrid, was published in Nature Geoscience.
It was supported by the Natural Environment Research Council, the US National Science foundation and the European Union.
Our work shows that external influences on the weather are important, and that even small changes in factors outside the climate system have a significant effect. These findings are significant because we are seeing the impact of these factors at a regional level.