Assessing the sequestration time scales of some ocean-based carbon dioxide reduction strategies
Assessing the sequestration time scales of some ocean-based carbon dioxide reduction strategies
复制标题
评估一些海洋二氧化碳减排策略的封存时间尺度
DOI：
10.1088/1748-9326/ac0be0
复制
发表时间：
2021
影响因子：
6.7
通讯作者：
Bell, T
中科院分区：
文献类型：
--
作者：
Siegel, D A;DeVries, T;Doney, S C;Bell, T
基于海洋的二氧化碳清除战略是实现温室气体负排放所需的一系列办法的重要组成部分。许多基于海洋的CDR战略依赖于将二氧化碳或有机碳（最终将成为二氧化碳）注入海洋内部，或增强海洋的生物泵。这些方法不会导致永久封存，因为洋流最终会将注入的二氧化碳返回到表面，在那里它将与大气平衡。在这里，一个模型的稳态全球海洋环流和混合是用来评估的时间尺度上，注入海洋内部的二氧化碳仍然从大气中隔离。由于连接某一深度位置和海面的路径数量无限，任何一个排放位置的封存时间都有分布。由此产生的概率分布是高度偏斜的，具有非常长的传输时间的长尾，使得平均封存时间比典型的时间尺度长得多。较深的排放位置将隔离有目的地注入的二氧化碳比较浅的要长得多，隔离时间的中位数通常是几十年到几个世纪，在北太平洋深处接近1000年。主要海洋盆地内部和之间的固碳时间存在很大差异，太平洋和印度洋盆地的固碳时间一般比大西洋和南大洋长。在50年时间范围内进行的评估表明，大部分注入的碳将保留在超过1000米的注入深度，但有几个地理例外，如西北大西洋。提高上层海洋生态系统生产力的海洋CDR战略，其目标是将更多的碳输出到深处，这将主要对大气中的二氧化碳水平产生短期影响，因为70%的二氧化碳将在50年内被输送回海洋表面。这里提出的结果将有助于规划适当的海洋CDR战略，可以帮助限制化石燃料二氧化碳排放造成的气候损害。
Ocean-based carbon dioxide (CO 2) removal (CDR) strategies are an important part of the portfolio of approaches needed to achieve negative greenhouse gas emissions. Many ocean-based CDR strategies rely on injecting CO 2 or organic carbon (that will eventually become CO 2) into the ocean interior, or enhancing the ocean's biological pump. These approaches will not result in permanent sequestration, because ocean currents will eventually return the injected CO 2 back to the surface, where it will be brought into equilibrium with the atmosphere. Here, a model of steady state global ocean circulation and mixing is used to assess the time scales over which CO 2 injected in the ocean interior remains sequestered from the atmosphere. There will be a distribution of sequestration times for any single discharge location due to the infinite number of pathways connecting a location at depth with the sea surface. The resulting probability distribution is highly skewed with a long tail of very long transit times, making mean sequestration times much longer than typical time scales. Deeper discharge locations will sequester purposefully injected CO 2 much longer than shallower ones and median sequestration times are typically decades to centuries, and approach 1000 years in the deep North Pacific. Large differences in sequestration times occur both within and between the major ocean basins, with the Pacific and Indian basins generally having longer sequestration times than the Atlantic and Southern Oceans. Assessments made over a 50 year time horizon illustrates that most of the injected carbon will be retained for injection depths greater than 1000 m, with several geographic exceptions such as the Western North Atlantic. Ocean CDR strategies that increase upper ocean ecosystem productivity with the goal of exporting more carbon to depth will have mainly a short-term influence on atmospheric CO 2 levels because∼ 70% will be transported back to the surface ocean within 50 years. The results presented here will help plan appropriate ocean CDR strategies that can help limit climate damage caused by fossil fuel CO 2 emissions.
影响因子：
16.6
作者：
Keller, David P.;Feng, Ellias Y.;Oschlies, Andreas
通讯作者：
Oschlies, Andreas
影响因子：
16.6
作者：
Holzer M;DeVries T;de Lavergne C
通讯作者：
de Lavergne C