New use of global warming potentials to compare cumulative and short-lived climate pollutants
New use of global warming potentials to compare cumulative and short-lived climate pollutants
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DOI：
10.1038/nclimate2998
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发表时间：
2016-08-01
影响因子：
30.7
通讯作者：
Forster, Piers M.
中科院分区：
文献类型：
--
作者：
Allen, Myles R.;Fuglestvedt, Jan S.;Forster, Piers M.
《联合国气候变化框架公约》(《气候公约》)缔约方要求就核算国家决定的减排贡献方面的共同温室气体指标提供指导(1)。衡量标准的选择会影响对减少二氧化碳等“累积气候污染物”与包括甲烷和黑碳在内的“短期气候污染物”(SLCP)的相对重视(2-6)。在这里，我们表明，广泛使用的100年全球变暖潜势(GWP(100))有效地衡量了累积污染物和SLCP对排放时间20-40年后实现变暖的相对影响。如果气候政策的总体目标是限制峰值变暖，GWP100因此夸大了当前SLCP排放的重要性，除非严格和立即减少所有气候污染物导致气温在本世纪中叶(7-10年)后不久接近峰值，这可能是将变暖限制在“远低于2摄氏度”所必需的(参考文献1)。GWP(100)可用于近似等同于累积污染物的一次性脉冲排放和SLCP11-13的排放速率的无限期持续变化。传统的二氧化碳当量目标对气候的影响是模棱两可的，除非分别说明累积污染物和SLCP的贡献。
Parties to the United Nations Framework Convention on Climate Change (UNFCCC) have requested guidance on common greenhouse gas metrics in accounting for Nationally determined contributions (NDCs) to emission reductions(1). Metric choice can affect the relative emphasis placed on reductions of ` cumulative climate pollutants' such as carbon dioxide versus `short-lived climate pollutants' (SLCPs), including methane and black carbon(2-6). Here we show that the widely used 100-year global warming potential (GWP(100)) effectively measures the relative impact of both cumulative pollutants and SLCPs on realized warming 20-40 years after the time of emission. If the overall goal of climate policy is to limit peak warming, GWP100 therefore overstates the importance of current SLCP emissions unless stringent and immediate reductions of all climate pollutants result in temperatures nearing their peak soon after mid-century(7-10), which may be necessary to limit warming to"well below2 degrees C" (ref.1). The GWP(100) can be used to approximately equate a one-off pulse emission of a cumulative pollutant and an indefinitely sustained change in the rate of emission of an SLCP11-13. The climate implications of traditional CO2-equivalent targets are ambiguous unless contributions fromcumulative pollutants and SLCPs are specified separately.