综合迄今中国境内湖泊沉积、冰心、泥炭、石笋、古土壤和洪积物获得的全新世数据及序列表明,早全新世气候变化是不稳定的,至少存在一次明显的降温事件,且表现为区域差异,其根本原因是受不同气候系统、复杂地形(特别是高原)的制约。但是,将不同地区、存在于9.0~7.6ka BP期间、500a至200a不等的气候突变或波动和记录与环北大西洋的8.2ka BP气候突变事件相对应,并归因于Laurentide冰盖的崩塌冰融水注入北大西洋造成的降温显然是草率的。中国主要地处季风气候区,加上目前我们所得序列的不同年代、样品精度、不同材料以及缺乏对气候事件前后精确的年代数据的控制,对于中国是否存在相同的或相似的气候降温事件是值得商榷的。如果真的存在,其时间跨度、降温幅度以及诱发机制又是什么,均需进一步认真研究。
We presented here a compilation of early Holocene records of lake sediments, ice cores, peat bogs, paleosols, stalagmites, and flood sediments from different settings in China. Proxy records showed that the unstable early Holocene was punctuated by at least an obvious centennial-scale cooling event, with different time duration and regional characteristics associating with different climate systems and complex topography. However, it may be cursory to correlate simply those climatic anomalies with time duration of 500 years to 200 years between 9.0 and 7.6 ka BP with the 8.2 ka BP cooling event revealed from circum-North Atlantic regions, let alone it attribute the cause to a decrease in North Atlantic thermolaline circulation triggered by catastrophic freshwater discharge from the Laurentide ice sheet collapse. Whether there was one synchronous or similar event or not in China, where the climate is mainly affected by the East Asian monsoon, is open to discussion, because many sites lack sufficiently precise dating, in dating material or number of dating especially around the anomalies, or lack sufficiently high time resolution, in sampling or in the recorder itself (e.g. flood or eolian sediments) to clearly demonstrate the existence of the event. If there did happen the cold event, more evidences are required in multiple dimensions to delineate the time duration, magnitude, and cause to happen of the event, so much work remains to be done.