A solution to the misrepresentations of CO2-equivalent emissions of short-lived climate pollutants under ambitious mitigation
A solution to the misrepresentations of CO2-equivalent emissions of short-lived climate pollutants under ambitious mitigation
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DOI：
10.1038/s41612-018-0026-8
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发表时间：
2018-01-01
影响因子：
9
通讯作者：
Macey, Adrian H.
中科院分区：
文献类型：
--
作者：
Allen, Myles R.;Shine, Keith P.;Macey, Adrian H.
虽然累积的二氧化碳（CO2）排放量在几个世纪以来主导着人为变暖，但未来几十年的温度也受到短期气候污染物（SLCP）的强烈影响，这使得为雄心勃勃的减缓目标估算累积排放预算变得复杂。使用传统的全球升温潜能值（GWP）将SLCP转换为“CO2当量”排放量错误地反映了它们对全球温度的影响。在这里，我们表明，一系列缓解情景下的变暖峰值是由变暖峰值时的累积二氧化碳排放量和该时间之前的非二氧化碳辐射强迫的线性组合决定的。这一点可以通过将累计非CO2强迫表示为累计CO2强迫当量（CO2-fe）排放量来理解。我们进一步表明，贡献CO2-Fe排放量很好地近似由一个新的用法的全球升温潜能值，表示GWP*，这涉及到累计CO2排放量与当前的SLCP排放率。全球升温潜能值 * 准确地表明了长寿命和短寿命污染物排放在广泛的时间尺度上对辐射强迫和温度的影响，包括在传统全球升温潜能值失败时的雄心勃勃的减缓措施。以GWP* 衡量，实施《巴黎协定》将使2030年的预期变暖率相对于无政策情景降低28%。从减缓努力对未来累积排放量的影响（使用全球升温潜能值 * 进行汇总）的角度来表述减缓努力，将使这些努力与对未来变暖的贡献直接相关，从而更好地为负担分担讨论以及为实现雄心勃勃的全球气温目标而采取的长期政策和措施提供信息。
While cumulative carbon dioxide (CO2) emissions dominate anthropogenic warming over centuries, temperatures over the coming decades are also strongly affected by short-lived climate pollutants (SLCPs), complicating the estimation of cumulative emission budgets for ambitious mitigation goals. Using conventional Global Warming Potentials (GWPs) to convert SLCPs to "CO2-equivalent" emissions misrepresents their impact on global temperature. Here we show that peak warming under a range of mitigation scenarios is determined by a linear combination of cumulative CO2 emissions to the time of peak warming and non-CO2 radiative forcing immediately prior to that time. This may be understood by expressing aggregate non-CO2 forcing as cumulative CO2 forcing-equivalent (CO2-fe) emissions. We show further that contributions to CO2-fe emissions are well approximated by a new usage of GWP, denoted GWP*, which relates cumulative CO2 emissions to date with the current rate of emission of SLCPs. GWP* accurately indicates the impact of emissions of both long-lived and short-lived pollutants on radiative forcing and temperatures over a wide range of timescales, including under ambitious mitigation when conventional GWPs fail. Measured by GWP*, implementing the Paris Agreement would reduce the expected rate of warming in 2030 by 28% relative to a No Policy scenario. Expressing mitigation efforts in terms of their impact on future cumulative emissions aggregated using GWP* would relate them directly to contributions to future warming, better informing both burden-sharing discussions and long-term policies and measures in pursuit of ambitious global temperature goals.