Demonstrating GWP*: a means of reporting warming-equivalent emissions that captures the contrasting impacts of short- and long-lived climate pollutants
Demonstrating GWP*: a means of reporting warming-equivalent emissions that captures the contrasting impacts of short- and long-lived climate pollutants
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DOI：
10.1088/1748-9326/ab6d7e
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发表时间：
2020-04-01
影响因子：
6.7
通讯作者：
Allen, Myles
中科院分区：
文献类型：
--
作者：
Lynch, John;Cain, Michelle;Allen, Myles
不同气候污染物的大气寿命和辐射影响都可能有显著差异，因此，使用单一比例因子（如100年全球变暖潜能值（GWP(100)））等量排放的指标可能会产生误导。另一种方法是将排放报告为导致类似变暖影响的“变暖当量”，而不需要对每个排放进行类似加权。全球变暖潜能值*是全球变暖潜能值的另一种应用，其中短期气候污染物排放的二氧化碳当量主要由其排放率的变化决定，它提供了一种产生变暖当量排放的直接方法。在这封信中，我们说明了甲烷（一种短寿命温室气体）和二氧化碳排放对气候的不同影响，并比较了一些简单排放情景下的GWP（100）和GWP* CO2当量。我们证明，GWP*提供了一个有用的变暖指示，而传统的GWP（100）应用在许多情况下，特别是在甲烷排放稳定或下降的情况下，是不够的，这对我们如何考虑排放不同气体成分的部门的“零排放”或“气候中和”目标具有重要意义。然后，我们说明了全球变暖潜能值*如何能够提供一种评估备选缓解战略的改进方法。GWP*允许直接从使用GWP（100）报告的二氧化碳当量排放量中计算变暖当量排放量，这与UNFCCC同意的《巴黎规则手册》一致，条件是将短期和累积气候污染物分开汇总，这对透明度至关重要。它提供了排放与预期变暖影响之间的直接联系，支持对实现长期温度目标的进展进行盘点，并与累积排放预算相兼容。
The atmospheric lifetime and radiative impacts of different climate pollutants can both differ markedly, so metrics that equate emissions using a single scaling factor, such as the 100-year Global Warming Potential (GWP(100)), can be misleading. An alternative approach is to report emissions as 'warming-equivalents' that result in similar warming impacts without requiring a like-for-like weighting per emission. GWP*, an alternative application of GWPs where the CO2-equivalence of short-lived climate pollutant emissions is predominantly determined by changes in their emission rate, provides a straightforward means of generating warming-equivalent emissions. In this letter we illustrate the contrasting climate impacts resulting from emissions of methane, a short-lived greenhouse gas, and CO2, and compare GWP(100) and GWP* CO2-equivalents for a number of simple emissions scenarios. We demonstrate that GWP* provides a useful indication of warming, while conventional application of GWP(100) falls short in many scenarios and particularly when methane emissions are stable or declining, with important implications for how we consider 'zero emission' or 'climate neutral' targets for sectors emitting different compositions of gases. We then illustrate how GWP* can provide an improved means of assessing alternative mitigation strategies. GWP* allows warming-equivalent emissions to be calculated directly from CO2-equivalent emissions reported using GWP(100), consistent with the Paris Rulebook agreed by the UNFCCC, on condition that short-lived and cumulative climate pollutants are aggregated separately, which is essential for transparency. It provides a direct link between emissions and anticipated warming impacts, supporting stocktakes of progress towards a long-term temperature goal and compatible with cumulative emissions budgets.