前寒武纪气候演化中的三个重要科学问题  

Three Important Issues of Precambrian Climate Evolution

作　　者：胡永云[1] 田丰[2] 

机构地区：[1]北京大学物理学院大气与海洋科学系气候与海-气实验室,北京100871 [2]清华大学地球系统科学研究中心,北京100084

出　　处：《气候变化研究进展》2015年第1期44-53,共10页Climate Change Research

基　　金：中国自然科学基金项目"新元古代冰雪地球融化后的气候"(41375072);"早期地球大气的甲烷;氨;有机气溶胶与暗弱太阳问题"(41175039);中国自然科学基金杰出青年项目"全球气候变化背景下的平流层气候变化和臭氧恢复"(41025018)

摘　　要：自地球形成至寒武纪将近40亿年（距今46亿-5.4亿年,通常称为前寒武纪）的气候演变是一个具有特殊难度和挑战性的研究领域,同时也是基础和前沿的研究领域。文章选择了前寒武纪气候演化中的三个重要科学问题进行综述：大气演化、两次全球性的冰川期以及暗弱太阳问题。关于大气演化,本文首先描述了大气成分的演化历史,然后简述了影响大气成分演化的三个基本过程：大气逃逸、两次大气氧含量突然增加、碳酸盐-硅酸盐循环及其对气候系统的负反馈作用。两次全球性的冰川期分别发生在古元古代（距今24亿-21亿年）和新元古代（距今8亿-5.8亿年）,文章简述了其成因以及相关的气候模拟结果。暗弱太阳问题是地球历史气候演化的一个经典问题,论文简要地综述了一些最新的研究成果和观点。The Precambrian extends over about 4 billion years from the formation of Earth to the beginning of the Cambrian（4.6 billion years ago to 0.54 billion years ago）. Studying climate evolution over such a long period is really challenging, but fundamental and intriguing. It is difficult to comprehensively review progress of studies in Precambrian climate evolution. Three important issues are chosen and discussed, which are atmospheric evolution,two extremely cold periods with global-scale glaciations, and the faint young Sun paradox. For atmospheric evolution,tendencies of atmospheric evolution are briefly reviewed, and three important processes involved in atmospheric evolution are introduced, which are atmospheric escape, two rapid increases of atmospheric oxygen, and the carbonatesilicate cycle and its negative feedback to climate. Two global-scale glaciations intervals happened at the Paleoproterozoic（2.4 billion years ago to 2.1 billion years ago） and the Neoproterozoic（0.8 billion years ago to 0.58 billion years ago）. Mechanisms of formation and deglaciation of the two global glaciations are reviewed. The faint young Sun paradox is a classical topic in Earth？s early climate studies. Here, most recent results are summarized.

关 键 词：大气演化 地球演化 生命演化 冰雪地球 暗弱太阳问题 

分 类 号：P532[天文地球—古生物学与地层学]