Advances in Earth Science
• Articles •
1, SHI Ya-feng
1,2, LI Heng-peng
YANG Bao, SHI Ya-feng, LI Heng-peng. SOME ADVANCES IN CLIMATIC CHANGE OVER THE PAST TWO MILLENNIA[J]. Advances in Earth Science, 2002, 17(1): 110-117.
Climatic and environmental change of the past two millennia is one of the core projects of PAGES (The Past Global Changes). Large quantity of research work and international proceedings have been carried out and made great progress in climatic and environmental change studies over the last 2000 years since the project (PAGES) took in effect. In this paper, historical background of the study is introduced firstly. Then, according to the research results of ice core, tree-ring and historical documents, current research status of climatic and environmental variations of the past 2 ka at home and abroad are summarized and reviewed. In particular, we pay more emphasis on spatial distribution characteristics of the “Medieval Warm Period” (MWP) and “Little Ice Age” (LIA). It is concluded that the distribution of the two great climatic episodes of MWP and LIA might not be global. Rather, evidence for climate changes show that the timing of MWP and LIA differed geographically. In other words, the cold or warm periods in one region were often not concident with those in other regions. In addition, several reconstructions of northern hemisphere temperatures over the past three years lead to the conclusion that the Northern hemisphere warmth in the middle ages was less than or at most comparable to the mid-20th-century warm period and average temperature during the middle ages was higher than that during the LIA of the last 1000 years. However, there are some efficiencies. For example, the causes of climatic changes over the past two millennia remain unknown. Even for MWP and LIA, the causes resulting in the two climatic events were open. Also there exist some problems in the parameterization of climatic models. For comparison, the studies in China are scarce.