讲座题目：Old carbon routed from land to the atmosphere by global river systems
主讲人：Joshua Dean 教授
主持人：张力伟 研究员
开始时间：2025-12-5 10:00
讲座地址：闵行校区河口海岸大楼A201-203会议室
主办单位：河口海岸科学研究院（海洋科学学院）
报告人简介：
Joshua Dean教授现任教于英国布里斯托大学（University of Bristol），曾任Communications Earth & Environment编辑，是水生生物地球化学领域的超新星学者。他专注于河流碳循环研究，尤以双碳同位素技术见长，其科研足迹横跨西伯利亚、加拿大、欧洲及澳大利亚。他主导的科研项目经费累计已超千万英镑，其中包括英国研究与创新署（UK Research & Innovation）颁发的标杆性项目——“未来领袖奖学金”（2022-2029）。Josh的学术成果丰硕，以一作和通讯在Nature（封面文章）、Science、Nature Water、Nature Communications、Reviews of Geophysics、Global Change Biology等顶级期刊发表论文40余篇。鉴于其卓越学术贡献，他于2025年荣膺旨在表彰英国顶尖学者的“菲利普·莱弗休姆地理学奖”。
报告内容：
Rivers and streams are an important pathway in the global carbon cycle, releasing carbon dioxide (CO2) and methane (CH4) from their water surfaces to the atmosphere. Until now, CO2 and CH4 emitted from rivers were thought to be predominantly derived from recent (sub-decadal) biomass production and, thus, part of ecosystem respiration. Here we combine new and published measurements to create a global database of the radiocarbon content of river dissolved inorganic carbon (DIC), CO2 and CH4. Isotopic mass balance of our database suggests that 59 ± 17% of global river CO2 emissions are derived from old carbon (millennial or older), the release of which is linked to river catchment lithology and biome. This previously unrecognized release of old, pre-industrial-aged carbon to the atmosphere from long-term soil, sediment and geologic carbon stores through lateral hydrological routing equates to 1.2 ± 0.3 Pg C year−1, similar in magnitude to terrestrial net ecosystem exchange. A consequence of this flux is a greater than expected net loss of carbon from aged organic matter stores. This requires a reassessment of the fate of anthropogenic carbon in terrestrial systems and in global carbon cycle budgets and models.
