Advances in halocarbon research to ensure success of the next phase of the Montreal Protocol in protecting the ozone layer and climate

随着《基加利修正案》于2019年生效，《关于消耗臭氧层物质的蒙特利尔议定书》进入了一个重要的新阶段，氢氟碳化合物(HFCs)的生产和使用将在大多数主要经济体受到控制。除了在保护臭氧层方面取得的成功之外，这一里程碑式的成就还将加强议定书对气候已经具有的实质性好处。然而，最近的科学进展表明，《蒙特利尔议定书》面临挑战，原因是新发现的被认为将逐步淘汰的消耗臭氧层物质的生产，不受《议定书》管制的消耗臭氧层化合物的快速增长，以及卤代烃降解产物可能产生的破坏性影响。这项提议通过结合最先进的大气测量技术、实验室实验和先进的数值模拟，解决了围绕这些挑战的最紧迫的科学问题。我们将：1)显著扩大大气测量覆盖范围，以更好地了解卤代烃排放的全球分布，并确定以前未知的大气趋势；2)结合行业模型和大气数据，以提高我们对生产量(《议定书》所控制的数量)、建筑物和产品中储存的卤代烃“库”和向大气排放之间的关系的理解；3)确定近期和未来可能出现的无管制、短期的卤化碳趋势，以及对臭氧层恢复时间尺度的影响；4)探索最新一代卤化碳的复杂大气化学，确定分解产品是否有可能促进气候变化或导致不可预见的负面环境后果；5)更好地量化卤化碳对气候的影响，完善用于比较国际协定和可能的缓解战略中的卤化碳影响的与气候和臭氧消耗有关的指标。这项工作将由卤化碳研究领域的领导人组成的联合体进行，他们在为《蒙特利尔议定书》各机构和政府间气候变化专门委员会作出贡献方面有着广泛的记录，确保将取得的新进展产生持久影响。

With the Kigali Amendment coming into force in 2019, the Montreal Protocol on Substances that Deplete the Ozone Layer has entered a major new phase in which the production and use of hydrofluorocarbons (HFCs) will be controlled in most major economies. This landmark achievement will enhance the Protocol's already-substantial benefits to climate, in addition to its success in protecting the ozone layer. However, recent scientific advances have shown that challenges lie ahead for the Montreal Protocol, due to the newly discovered production of ozone-depleting substances (ODS) thought to be phased-out, rapid growth of ozone-depleting compounds not controlled under the Protocol, and the potential for damaging impacts of halocarbon degradation products. This proposal tackles the most urgent scientific questions surrounding these challenges by combining state-of-the-art techniques in atmospheric measurements, laboratory experiments and advanced numerical modelling. We will: 1) significantly expand atmospheric measurement coverage to better understand the global distribution of halocarbon emissions and to identify previously unknown atmospheric trends, 2) combine industry models and atmospheric data to improve our understanding of the relationship between production (the quantity controlled under the Protocol), "banks" of halocarbons stored in buildings and products, and emissions to the atmosphere, 3) determine recent and likely future trends of unregulated, short-lived halocarbons, and implications for the timescale of recovery of the ozone layer, 4) explore the complex atmospheric chemistry of the newest generation of halocarbons and determine whether breakdown products have the potential to contribute to climate change or lead to unforeseen negative environmental consequences, 5) better quantify the influence of halocarbons on climate and refine the climate- and ozone-depletion-related metrics used to compare the effects of halocarbons in international agreements and in the design of possible mitigation strategies. This work will be carried out by a consortium of leaders in the field of halocarbon research, who have an extensive track record of contributing to Montreal Protocol bodies and the Intergovernmental Panel on Climate Change, ensuring lasting impact of the new developments that will be made.