New Insights on the Age and Climate Mitigation Significance of Shelf Sea Sedimentary Organic Carbon Stores

有机碳（OC）在海岸和大陆架沉积物中的埋藏有助于在地质时间尺度上调节大气CO2，并可能减缓当今气候变化。目前正在进行重大努力，以绘制和量化我们大陆架海域的有机碳，包括首次评估国家专属经济区（EEZ）沉积物有机碳资源。然而，在实现对这种自然资本的可靠核算方面有一些基本要求，即限制OC来源，也许更重要的是限制OC本身的年龄。当这些富含有机碳的沉积物受到自然或（越来越多的）人为压力，有可能将大量的CO2释放到水柱中，并可能释放到大气中。在本提案中，我们的目标是对燃烧的有机物的热（加热）馏分的放射性碳年龄提供独特的限制，丰富的海洋沉积物从英国专属经济区，以测试的假设，OC在近海沉积物中的反应是由源驱动，年龄和命运的OC。我们的研究是准备突出的关键作用，放射性碳测年，现在必须发挥国家OC会计从大陆架海洋环境的气候减缓服务。

The burial of organic carbon (OC) in coastal and continental shelf sediments contributes to the regulation of atmospheric CO2 on geological timescales and potentially mitigates present-day climate change. Major efforts are now underway to map and quantify the OC held in our continental shelf seas, including the first ever assessment of a national Exclusive Economic Zone (EEZ) sediment OC resource. However, there are fundamental requirements in the realization of a reliable accounting of this natural capital, namely to constrain the OC source(s) and, perhaps more significantly, the age of the OC itself. When these OC-rich sediments are disturbed, either by natural or (increasingly) anthropogenic pressures, there is potential for significant quantities of CO2 to be released to the water column and potentially the atmosphere In this proposal we aim to provide a unique constraint on the radiocarbon age of thermal (heated) fractions of combusted organic-rich marine sediments from the UK EEZ in order to test the hypothesis that OC reactivity in offshore sediments is driven by the source, age and fate of OC. Our research is poised to highlight the key role which radiocarbon dating must now play in national OC accounting for climate mitigation services from shelf sea environments.