National post-2020 greenhouse gas targets and diversity-aware leadership
National post-2020 greenhouse gas targets and diversity-aware leadership
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DOI：
10.1038/nclimate2826
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发表时间：
2015-12-01
影响因子：
30.7
通讯作者：
Meinshausen, Nicolai
中科院分区：
文献类型：
--
作者：
Meinshausen, Malte;Jeffery, Louise;Meinshausen, Nicolai
要实现与工业化前水平相比，将全球变暖控制在2摄氏度或1.5摄氏度以下的集体目标，就需要向一个完全脱碳的世界过渡。2025年或2030年这样一条道路上的年度温室气体排放量可以通过各种分配方案分配给各个国家。我们重新分析了气专委文献分配数据库，并提供了三种方法的国家一级详细情况。然而，在现阶段，假设国际社会将就单一分配方案达成一致似乎是乌托邦式的。在这里，我们调查一种让一个主要经济体国家带头的方法。然后，其他国家以自下而上的方式确定他们认为公平的可比目标，例如，“人均趋同”或“同等累积人均”方法。例如，我们发现，欧盟28国2030年的目标是比1990年低67%，美国的2025年目标是比2005年低54%，中国的2030年目标是比2010年低32%，这可能确保在我们的说明性违约情况下实现2摄氏度的目标。将这些目标与2020年后的减排目标进行比较，显示出很大的差距。目前，任何主要排放国都不能声称在全球范围内为避免全球变暖2摄氏度的共同努力表现出必要的领导能力。
Achieving the collective goal of limiting warming to below 2 degrees C or 1.5 degrees C compared to pre-industrial levels requires a transition towards a fully decarbonized world. Annual greenhouse gas emissions on such a path in 2025 or 2030 can be allocated to individual countries using a variety of allocation schemes. We reanalyse the IPCC literature allocation database and provide country-level details for three approaches. At this stage, however, it seems utopian to assume that the international community will agree on a single allocation scheme. Here, we investigate an approach that involves a major-economy country taking the lead. In a bottom-up manner, other countries then determine what they consider a fair comparable target, for example, either a 'per-capita convergence' or 'equal cumulative per-capita' approach. For example, we find that a 2030 target of 67% below 1990 for the EU28, a 2025 target of 54% below 2005 for the USA or a 2030 target of 32% below 2010 for China could secure a likely chance of meeting the 2 degrees C target in our illustrative default case. Comparing those targets to post-2020 mitigation targets reveals a large gap. No major emitter can at present claim to show the necessary leadership in the concerted effort of avoiding warming of 2 degrees C in a diverse global context.