深部碳循环的环境气候效应

The effect of the deep carbon cycle on environment and climate

地球表层温度主要由接收的太阳辐射能量及大气温室气体的保温能力共同控制。CO_(2)等温室气体通过对大气温度的调节影响着全球环境气候变化,工业革命以来全球CO_(2)排放量的增加被认为是全球变暖的重要原因,地质历史时期大气CO_(2)浓度的波动与温室和冰室气候的交替出现相对应。地球超过90%的碳赋存于深部,因此地球深部过程的些许波动便会影响到地表碳含量,进而深刻影响着地球的环境气候变化。以往的研究注重地表碳循环对环境气候的影响,对深部碳的贡献考虑不足。最近十余年全球开展了详细的深部碳循环研究,基于已经取得的重要成果,本文从大火成岩省、裂谷和俯冲带的视角对深部碳循环驱动的环境气候效应进行了系统回顾。认为未来的研究需要对地球深部碳循环通量和碳同位素组成进行更精确的定量,这是我们认识深部碳循环对地表环境气候影响的基础;除了碳元素本身我们还需要关注其他挥发性元素和有害金属元素的综合效应;俯冲带作为全球壳-幔相互作用和物质交换循环最重要的场所,应该是进行深部碳循环观察和环境气候效应研究的重点。

The temperature of the Earth’s surface is mainly controlled by the energy received from solar radiation and the holding capacity of greenhouse gases in the atmosphere.Greenhouse gases,such as CO_(2)and CH_(4),affect global climate change by regulating atmospheric temperature.The increase in global CO_(2)emissions since the Industrial Revolution is considered as one important cause of global warming.The fluctuation of atmospheric CO_(2)concentration in the geological period also corresponds to the alternate appearance of greenhouse and icehouse climates.It is worth noting that more than 90%of Earth’s carbon is stored in the deep Earth,so fluctuations in deep processes can affect the amount of carbon on the surface,which in turn has a profound impact on the environment and climate of the Earth.Previous studies mainly focused on the impact of the exogenic carbon cycle on the environment and climate but did not sufficiently consider the contribution of the deep carbon.In recent decades,detailed deep carbon cycle research has been carried out over the world.In this study,the effect of the deep carbon cycle on the environment and climate has been systematically reviewed from the perspective of the large igneous provinces,rifts,and subduction zones,and we suggested that future works need to accurately quantify the flux of the deep carbon cycle and their carbon isotope compositions,which is the basis for us to understand the influence of the deep carbon cycle on the exogenic environment and climate.In addition to carbon itself,we also need to pay more attention to the combined effect of other volatile elements and toxic metal elements.The subduction zone is considered as the most important site for crustal recycling and crust-mantle interaction,thus a comprehensive study on the deep carbon cycle in the subduction zone and its environmental and climatic effects should be strengthened in the future.