气候不稳定性的重要发现——对国外冰芯研究进展的综述

CLIMATE INSTABILITY RECORDED IN ICE CORES AN OVERVIEW OF RECENT FINDINGS BY ICE CORE STUDIES

冰芯分析使气候环境变化研究取得重大进展。最近格陵兰冰盖顶部的一对冰芯证实了末次冰期出现过多次冷暖时段的快速转换。ＧＲＩＰ冰芯还发现未次间冰期盛期也为冷期所打断。安第斯山冰芯揭示了末次冰期热带气候变化之谜。过去被广泛接受的气候稳定的间冰期和气候多变的冰期的结论，以及恒温式热带冰期气候运转模式都面临挑战。ＧＩＳＰ２冰芯钻孔温度测量查明了极地对气候变化的放大作用。未来全球变暖的后果很可能是全新世稳定气候的结束，多变的灾难性气候的来临这一严竣问题摆在人类面前。

Analyses of ice cores drilled through Greenland and Antarcitica ice sheets and high glaciers have produced remarkable advances in our understanding of the evolution of Earths climate. The past a few years have seen a revolution in our thinking on climate variability and tropic climate sensitivity, because of the signs of fast climate oscillations and cooling ice age tropics displeayed in the ice cores. One of the principal progress made by GRIP and GISP2 ice cores has been the demonstration that the last glacial period was punctuated by a series of abrupt warm interstadials during which temperature increased by about 5℃￣8℃ for a few hundred years. Another sigificant new finding has been the document that the Eemian interglacial was interrupted by a series of severe cold periods, which began extremely rapidly and lasted from decades to centuries. Thirdly, a high glacier ice core opens a view of the ice age tropics. Two ice cores from Andes found that the tropics did share in the cooling as much as 8℃ to 12℃ lower than today during the late glacial stage. And the last, analysis of borehole temperature at GISP2 reveals that polar amplification of climate change is a central characteristic of Earths climate. With these new discoveries, the widely accepted concepts of a noisy glacial climate and a quiet interglacial climate as well as thermostat tropics came under challenge. And they result in the questions about the consequences of future global warming. Will the greenhouse effect end the recent climate stability and bring rapid climate change to our doorstep?