Blue carbon gains from glacial retreat along Antarctic fjords: What should we expect?
Blue carbon gains from glacial retreat along Antarctic fjords: What should we expect?
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DOI：
10.1111/gcb.15055
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发表时间：
2020-05-01
影响因子：
11.6
通讯作者：
Zwerschke, Nadescha
中科院分区：
文献类型：
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作者：
Barnes, David K. A.;Sands, Chester J.;Zwerschke, Nadescha
大气中不断上升的二氧化碳正在加剧气候变化，但它也在推动全球绿化，尤其是极地绿化。然而，大多数蓝色碳汇（由海洋生物持有）正在萎缩，这很重要，因为这些是真正的碳封存热点。极地蓝碳随着高纬度大陆架地区海冰的减少而增加。海冰（海冰、冰架和冰川退缩）的损失对气候变化产生了宝贵的负反馈。蓝碳随着海冰和冰架的损失而变化，但不知道蓝碳对峡湾冰川退缩的反应。通过对西南极半岛（WAP）三个峡湾的调查，我们得出了一个可测试的冰川退缩驱动蓝碳收益的估计。我们首先用40年的平均冰川退缩率乘以退缩的WAP峡湾的数量和它们的暴露时间。我们将这一区域乘以现有数据集的区域底栖动物碳平均值，表明WAP峡湾每年产生3,130吨新的底栖动物碳（t zC/年），并吸收1,780 t zC/年。我们通过捕获和分析沿新兴WAP峡湾的204张高分辨率海底图像来测试这一点。这些图像中的生物群被确定为每13个官能团的密度。每个个体的平均储存量碳从文献值中得到每个区域的底栖动物储存量碳，乘以随着时间的推移暴露的峡湾面积，其估计值增加到4,536 t zC/年。本研究的目的是建立由南极峡湾冰川退缩引起的蓝碳变化的可测试估计，从而确定其与极地和其他碳汇相比的相对重要性。
Rising atmospheric CO2 is intensifying climate change but it is also driving global and particularly polar greening. However, most blue carbon sinks (that held by marine organisms) are shrinking, which is important as these are hotspots of genuine carbon sequestration. Polar blue carbon increases with losses of marine ice over high latitude continental shelf areas. Marine ice (sea ice, ice shelf and glacier retreat) losses generate a valuable negative feedback on climate change. Blue carbon change with sea ice and ice shelf losses has been estimated, but not how blue carbon responds to glacier retreat along fjords. We derive a testable estimate of glacier retreat driven blue carbon gains by investigating three fjords in the West Antarctic Peninsula (WAP). We started by multiplying ~40 year mean glacier retreat rates by the number of retreating WAP fjords and their time of exposure. We multiplied this area by regional zoobenthic carbon means from existing datasets to suggest that WAP fjords generate 3,130 tonnes of new zoobenthic carbon per year (t zC/year) and sequester >780 t zC/year. We tested this by capture and analysis of 204 high resolution seabed images along emerging WAP fjords. Biota within these images were identified to density per 13 functional groups. Mean stored carbon per individual was assigned from literature values to give a stored zoobenthic Carbon per area, which was multiplied up by area of fjord exposed over time, which increased the estimate to 4,536 t zC/year. The purpose of this study was to establish a testable estimate of blue carbon change caused by glacier retreat along Antarctic fjords and thus to establish its relative importance compared to polar and other carbon sinks.