Climatic Change and Human Activities in the 4th to 10th Centuries
4〜10世紀における気候変動と人間活動

Masatoshi YOSHINO
2009 Journal of Geography (Chigaku Zasshi)  
The global climate is known to have been relatively warm during the period from the 4th to 10th centuries, although there were slightly different fluctuation patterns locally and regionally.
doi:10.5026/jgeography.118.1221 fatcat:6y4xqsqpebayjktx3o4rbulsyu