The difficulties in climate change negotiations together with the recent withdrawal of the U.S. from the Paris Agreement call for new cooperative mechanisms to enable a resilient international response. In this study we propose an approach to aid such negotiations based on quantifying the benefits of interregional cooperation and distributing them among the participants in a fair manner. Our approach is underpinned by advanced optimisation techniques that automate the screening of millions of alternatives for differing levels of cooperation, ultimately identifying the most cost-effective solutions for meeting emission targets. We apply this approach to the Clean Power Plan, a related act in the U.S. aiming at curbing carbon emissions from electricity generation, but also being withdrawn. We find that, with only half of the states cooperating, the cost of electricity generation could be reduced by US$41 billion per year, while simultaneously cutting carbon emissions by 68% below 2012 levels. These win–win scenarios are attained by sharing the emission targets and trading electricity among the states, which allows exploiting regional advantages. Fair sharing of dividends may be used as a key driver to spur cooperation since the global action to mitigate climate change becomes beneficial for all participants. Even if global cooperation remains elusive, it is worth trying since the mere cooperation of a few states leads to significant benefits for both the U.S. economy and the climate. These findings call on the U.S. to reconsider its withdrawal but also boost individual states to take initiative even in the absence of federal action.

中文翻译：

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采取全球行动的时间：为有效缓解气候变化而采取的最佳合作方式

气候变化谈判中的困难加上美国最近退出《巴黎协定》，要求建立新的合作机制，以作出有弹性的国际反应。在这项研究中，我们提出了一种基于量化区域间合作的利益并以公平的方式在参与者之间分配利益的方式来协助此类谈判的方法。我们的方法以先进的优化技术为基础，该技术可以自动筛选针对不同合作水平的数百万种替代品，从而最终确定最符合成本效益的解决方案，以实现排放目标。我们将此方法应用于“清洁电力计划”，这是美国的一项相关法案，旨在遏制发电产生的碳排放，但也已被撤销。我们发现，只有一半的州合作，每年可以减少410亿美元的发电成本，同时将碳排放量比2012年的水平降低68％。通过在各州之间共享排放目标并进行电力交易，可以实现这些双赢的局面，从而可以充分利用区域优势。公平分配股利可以用作促进合作的主要动力，因为减轻气候变化的全球行动对所有参与者都是有益的。即使全球合作仍然遥遥无期，也值得尝试，因为只有少数几个州的合作才能为美国经济和气候带来重大利益。这些发现呼吁美国重新考虑退出，但即使在没有采取联邦行动的情况下，也可以促使各个州主动采取行动。