Modeling the fate of methane hydrates under global warming
Modeling the fate of methane hydrates under global warming
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DOI：
10.1002/2014gb005011
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发表时间：
2015-05-01
影响因子：
5.2
通讯作者：
Burwicz, Ewa
中科院分区：
文献类型：
--
作者：
Kretschmer, Kerstin;Biastoch, Arne;Burwicz, Ewa
海洋沉积物中蕴藏的大量甲烷水合物很容易受到气候变化的影响。底层水温的变化可能会导致其不稳定，并将甲烷释放到水柱甚至大气中。在多模型方法中，评估了不稳定的甲烷水合物对下一世纪全球气候的可能影响。重点是改变底层水温，以推断全球甲烷水合物库存对未来气候变化的响应。通过结合使用后播高分辨率海洋环流模拟和下世纪气候模型来评估当前和未来的底层水温。使用 Wallmann 等人最近提出的参数化传递函数来计算不断变化的全球水合物库存。 （2012）。我们发现，目前世界海洋甲烷水合物总库存估计为 1146Gt 甲烷碳。在未来 100 年内，全球库存量可能会减少约 0.03%（从海底释放约 473 吨甲烷）。与目前人为甲烷的年排放量相比，到2100年，水合物融化释放的甲烷量很小，不会对全球气候产生重大影响。从区域范围来看，未来100年海底变暖将导致甲烷水合物沉积量相对大幅减少，其中北极和南卡罗来纳州近海的布莱克海岭地区受影响最严重。
Large amounts of methane hydrate locked up within marine sediments are vulnerable to climate change. Changes in bottom water temperatures may lead to their destabilization and the release of methane into the water column or even the atmosphere. In a multimodel approach, the possible impact of destabilizing methane hydrates onto global climate within the next century is evaluated. The focus is set on changing bottom water temperatures to infer the response of the global methane hydrate inventory to future climate change. Present and future bottom water temperatures are evaluated by the combined use of hindcast high-resolution ocean circulation simulations and climate modeling for the next century. The changing global hydrate inventory is computed using the parameterized transfer function recently proposed by Wallmann et al. (2012). We find that the present-day world's total marine methane hydrate inventory is estimated to be 1146Gt of methane carbon. Within the next 100years this global inventory may be reduced by approximate to 0.03% (releasing approximate to 473Mt methane from the seafloor). Compared to the present-day annual emissions of anthropogenic methane, the amount of methane released from melting hydrates by 2100 is small and will not have a major impact on the global climate. On a regional scale, ocean bottom warming over the next 100years will result in a relatively large decrease in the methane hydrate deposits, with the Arctic and Blake Ridge region, offshore South Carolina, being most affected.