摘要
地质历史上充满着冰盖消长 (“暖室期”和“冰室期” ,“冰期”和“间冰期”)与大气CO2 增减的周期性变化 ,而两者之间的关系并不清楚。由于冰盖变化的地质标志比大气CO2 变化的标志容易认识 ,长期以来古气候研究侧重“冰” ,而对“碳”即碳循环的研究不足 ,通常将碳循环的变化解释为冰盖变化的结果。近年来越来越多的发现表明 ,单纯用水循环的物理过程不能解释冰盖演变的许多现象 ,而且大气CO2 变化往往领先于冰盖。揭示碳循环变化对冰盖演变的影响 ,认识生物地球化学过程在冰期旋回中的作用 ,将不同纬区对地球轨道驱动全球气候的影响区分开来 ,才有可能正确预测未来气候的演变方向。
The ice cap on the Earth has been repeatedly appearing and varying in its size throughout the geological history, so does the CO 2 atmospheric concentration. However, it remains unclear how the variations of the two factors, ice and carbon, are interrelated with each other. Since the ice cap variations are better recognizable in geological records as compared to the CO 2 , paleoclimatology has been biased to the ice change studies, with insufficient attention paid to the carbon system. Traditionally, the observed variations in carbon system are considered to be a response to ice sheet changes; yet the recent discoveries provide an increasing number of phenomena in ice sheet variations which can not be explained by solely physical processes in hydrological circulation, and an increasing number of evidences show that the changes in atmospheric CO 2 have preceded those in ice volume. Thus, there is an urgent need to uncover the effect of carbon system changes on ice cap variations, to assess the role of biogeochemical processes in glacial cycles, and to disintegrate the contributions from different latitudinal zones to the orbital forcing of the global climate system, if we are to predict the trend of future climate changes scientifically.
出处
《地学前缘》
EI
CAS
CSCD
2002年第1期85-93,共9页
Earth Science Frontiers
基金
国家自然科学基金项目 ( 4 99995 6 0 )
国家重点基础研究项目 ( 2 0 0 0 0785 0 5 )
关键词
冰期旋回
碳循环
地球气候系统
温室效应
地球轨道周期
glacial cycles
carbon cycle
Earth climate system
green-house effect
Earth orbital periodicity
