Climate model simulations can enrich the knowledge of past climate changes, especially in multi-decadal and longer-term temperature changes. The temperature variability over multi-decadal and longer timescales is significant and dominant in the millennium-long, large-scale reconstructions and model simulations for the Northern Hemisphere. 

An increasing number of studies have focused on data-model comparison over the past decade, making significant achievements. However, the temporal patterns in the reconstructed and simulated temperature series are not well understood and require a detailed assessment and comparison. 

Recently, scientists from the Northwest Institute of Eco-Environment and Resources of Chinese Academy of Sciences compared the reconstructed and simulated temperature series for the Northern Hemisphere at multi-decadal and longer-term timescales by evaluating their covariance, climate sensitivity and amplitude of temperature changes.  

In this study, scientists assessed the temperature variability over multi-decadal and longer timescales reconstructions for the Northern Hemisphere, evaluated the covariance in reconstructed and simulated temperatures since 850CE, and investigated the climate sensitivity of reconstructions and simulations by exploring the correlation with solar and volcanic forcing. 

Besides, they also especially emphasized the differences between sub-periods, estimated the amplitudes of temperature changes in different reconstructions and model simulations by calculating the temperature differences between typical warm and cold climate states. 

This study has implications for future large-scale and long-term temperature changes reconstruction work for the Northern Hemisphere, and the findings have been published in the Earth Sciences in an article entitled “Evaluation of multidecadal and longer-term temperature changes since 850 CE based on Northern Hemisphere proxy-based reconstructions and model simulations”.