Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, 7001, Australia.
National Institute of Water and Atmospheric Research, Wellington, 6021, New Zealand.
J Phycol. 2022 Jun;58(3):347-363. doi: 10.1111/jpy.13249. Epub 2022 Apr 24.
Carbon sequestration is defined as the secure storage of carbon-containing molecules for >100 years, and in the context of carbon dioxide removal for climate mitigation, the origin of this CO is from the atmosphere. On land, trees globally sequester substantial amounts of carbon in woody biomass, and an analogous role for seaweeds in ocean carbon sequestration has been suggested. The purposeful expansion of natural seaweed beds and aquaculture systems, including into the open ocean (ocean afforestation), has been proposed as a method of increasing carbon sequestration and use in carbon trading and offset schemes. However, to verify whether CO fixed by seaweeds through photosynthesis leads to carbon sequestration is extremely complex in the marine environment compared to terrestrial systems, because of the need to jointly consider: the comparatively rapid turnover of seaweed biomass, tracing the fate of carbon via particulate and dissolved organic carbon pathways in dynamic coastal waters, and the key role of atmosphere-ocean CO exchange. We propose a Forensic Carbon Accounting approach, in which a thorough analysis of carbon flows between the atmosphere and ocean, and into and out of seaweeds would be undertaken, for assessing the magnitude of CO removal and robust attribution of carbon sequestration to seaweeds.
碳封存被定义为将含碳分子安全储存>100 年，在为气候缓解而去除二氧化碳的背景下，这些 CO 的来源是大气。在陆地上，树木在木质生物质中大量封存碳，而海藻在海洋碳封存中也具有类似的作用。有人提议有目的地扩大天然海藻床和水产养殖系统，包括进入开阔海域（海洋造林），以此作为增加碳封存并在碳交易和抵消计划中加以利用的一种方法。然而，与陆地系统相比，海洋环境中要验证通过光合作用固定的 CO 2 是否导致碳封存极其复杂，因为需要共同考虑：海藻生物量的快速周转、通过动态沿海水域中的颗粒和溶解有机碳途径追踪碳的命运，以及大气-海洋 CO 交换的关键作用。我们提出了一种取证碳核算方法，其中将对大气和海洋之间以及海藻内外的碳流进行全面分析，以评估 CO 去除的程度，并将碳封存可靠地归因于海藻。
