Large global variations in the carbon dioxide removal potential of seaweed farming due to biophysical constraints
Large global variations in the carbon dioxide removal potential of seaweed farming due to biophysical constraints
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DOI：
10.1038/s43247-023-00833-2
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发表时间：
2023-06-15
影响因子：
7.9
通讯作者：
Davis, Kristen A.
中科院分区：
文献类型：
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作者：
Arzeno-Soltero, Isabella B.;Saenz, Benjamin T.;Davis, Kristen A.
据估计，到2050年，要实现国际气候目标，每年要从大气中清除40亿吨以上的二氧化碳（Gt-CO2年（-1））。清除二氧化碳的一种策略是海藻养殖;然而，其全球潜力仍然高度不确定。在这里，我们应用一个动态的海藻生长模型，包括生长限制机制，如硝酸盐供应，估计全球潜在产量的四种类型的海藻。我们估计，收获1 Gt/年（-1）的海藻碳将需要在赤道太平洋最具生产力的专属经济区种植超过100万km（2）;种植面积需要增加两倍才能达到额外的1 Gt/年（-1）的碳收获，这表明在最具生产力的沃茨之外，碳收获效率急剧下降。提高年度收获产量估计的准确性需要更好地了解生物物理制约因素，如海藻损失率（例如，在赤道太平洋100万平方公里最具生产力的专属经济区内进行养殖，每年可产生1千兆吨海藻碳;然而，根据全球动态海藻生长模拟，在这些生产性沃茨之外，碳收获效率急剧下降。
Estimates suggest that over 4 gigatons per year of carbon dioxide (Gt-CO2 year(-1)) be removed from the atmosphere by 2050 to meet international climate goals. One strategy for carbon dioxide removal is seaweed farming; however its global potential remains highly uncertain. Here, we apply a dynamic seaweed growth model that includes growth-limiting mechanisms, such as nitrate supply, to estimate the global potential yield of four types of seaweed. We estimate that harvesting 1 Gt year(-1) of seaweed carbon would require farming over 1 million km(2) of the most productive exclusive economic zones, located in the equatorial Pacific; the cultivation area would need to be tripled to attain an additional 1 Gt year(-1) of harvested carbon, indicating dramatic reductions in carbon harvest efficiency beyond the most productive waters. Improving the accuracy of annual harvest yield estimates requires better understanding of biophysical constraints such as seaweed loss rates (e.g., infestation, disease, grazing, wave erosion).Cultivating 1 million km(2) of the most productive exclusive economic zones, which are in the equatorial Pacific, could produce 1 Gt of seaweed carbon per year; however, beyond these productive waters carbon harvest efficiency drops dramatically, according to global dynamic seaweed growth simulations.