What is the limit of climate engineering by stratospheric injection of SO 2
What is the limit of climate engineering by stratospheric injection of SO 2
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DOI：
10.5194/acp-15-9129-2015
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发表时间：
2015-08
影响因子：
6.3
通讯作者：
U. Niemeier;C. Timmreck
中科院分区：
文献类型：
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作者：
U. Niemeier;C. Timmreck
抽象的。讨论了将二氧化硫(SO2)注入平流层以形成人工平流层气溶胶层，作为太阳辐射管理的一种选择。辐射强迫的减少依赖于二氧化硫的喷射量，但气溶胶模式研究表明，随着喷射率的增加，强迫效率降低。然而，这些研究中没有一项认为喷射速率大于20Tg(S)yr−1。但如果排放状况在本世纪持续下去，这对于抵消预期的强烈人为强迫是必要的。为了了解大量SO2注入的影响，我们计算了高达100Tg(S)yr−1的SO2注入的影响。我们通过考虑不同的注入策略并通过与其他模型所得结果的比较来估计我们结果的可靠性。我们的计算表明，这种地球工程方法的效率(用硫酸盐气溶胶强迫与注入速率之比表示)呈指数衰减。这一结果意味着，在保持业务正常的同时，将2020年的温度保持在预期水平所需的硫酸盐太阳辐射管理战略将需要在对应于60百帕的高度向大气注入约45 Tg(S)年−1(±15%或7 Tg(S)yr−1)。这一排放量相当于公吨的5至7倍。皮纳图博火山每年都会喷发。
Abstract. The injection of sulfur dioxide (SO2) into the stratosphere to form an artificial stratospheric aerosol layer is discussed as an option for solar radiation management. The related reduction of radiative forcing depends upon the injected amount of sulfur dioxide, but aerosol model studies indicate a decrease in forcing efficiency with increasing injection rate. None of these studies, however, consider injection rates greater than 20 Tg(S) yr−1. But this would be necessary to counteract the strong anthropogenic forcing expected if "business as usual" emission conditions continue throughout this century. To understand the effects of the injection of larger amounts of SO2, we have calculated the effects of SO2 injections up to 100 Tg(S) yr−1. We estimate the reliability of our results through consideration of various injection strategies and from comparison with results obtained from other models. Our calculations show that the efficiency of such a geoengineering method, expressed as the ratio between sulfate aerosol forcing and injection rate, decays exponentially. This result implies that the sulfate solar radiation management strategy required to keep temperatures constant at that anticipated for 2020, while maintaining business as usual conditions, would require atmospheric injections of approximately 45 Tg(S) yr−1 (±15 % or 7 Tg(S) yr−1) at a height corresponding to 60 hPa. This emission is equivalent to 5 to 7 times the Mt. Pinatubo eruption each year.