Towards treaty verification of all non-CO2 long-lived greenhouse gases

根据国际协定或排放交易计划，许多国家必须报告长寿命温室气体的排放量。希望在不久的将来，这些方案将根据全球气候条约扩展到地球上的每个国家，以遏制这些气体对环境的破坏性影响。虽然目前各国的排放量报告是基于“自下而上”的方法（即通过考虑化石燃料使用等因素来编制排放清单），但很明显，如果这些条约要取得成功，对这些估计数的准确和独立核查至关重要。在这里，我建议通过开发第一个系统来解决这个问题，该系统可以确定所有最具破坏性的非二氧化碳LLGHG的排放量：甲烷，一氧化二氮，氯氟烃（CFCs），氢氯氟烃（HCFCs），氢氟碳化物（HFCs），哈龙，全氟化碳（PFCs）和六氟化硫（SF6）。它们加起来占人类对“温室效应”贡献的三分之一。提出了一种新的模拟系统，用于利用大气测量确定低温室气体排放量。该方法将使用两个互补的模型，通过允许在监测地点附近以高分辨率和远离监测地点的低分辨率得出排放量，来最大限度地利用可以从测量中提取的信息。由于这一系统中的模型和技术的独特组合，将有可能首次同时得出上述所有低温室气体的排放量，从而使正在确定的领域之间能够共享互利的信息。两个最重要的非CO2低温室气体，甲烷和一氧化二氮，将需要特别注意在拟议的“反演”。这些气体与大多数低温室气体的不同之处在于，它们具有大量但非常不确定的天然成分。它们的年与年之间的变化一直是许多辩论的主题，它们未来可能的增长也知之甚少。为了进一步了解这些气体的行为，我将与瑞士联邦森林、雪和景观研究所和马萨诸塞州理工学院的合作伙伴合作，采用新技术：对最先进的湿地甲烷排放模型进行参数估计，并将一氧化二氮的第一个高频同位素测量纳入拟议的模型框架。拟议的研究将提供一个独特的机会来回答现代大气化学中最重要的问题之一：羟基自由基的浓度和变异性是什么？这是一个关键问题，因为羟基自由基是大气污染物中最大的单一“清洁剂”。本提案中概述的新颖的多物种反演将允许对这一数量进行更严格的限制，提供重要的信息，以测试未来的大气化学和传输模型，并预测未来LLGHG的寿命可能如何变化。该提案的成果将是对目前所有非二氧化碳低温室气体的最准确和最全面的排放量估计，增加我们对甲烷和一氧化二氮源的划分和变异性的基本了解，以及对羟基自由基行为的更多了解。这些目标被认为对评估《联合王国气候变化法》（2008年）特别重要，因此，环境和气候变化部和环境、食品和农村事务部将提供支持信。从拟议的工作中获得的理解和开发的技术将为这些重要温室气体的国际条约核查铺平道路。

Many countries are required to report emissions of long-lived greenhouse gasses (LLGHG) under international agreements or emissions trading schemes. In the near future it is hoped that such programmes will be extended to every nation on Earth under a global climate treaty, to curb the damaging effect these gasses have on the environment. Whilst national emissions are currently reported based on 'bottom-up' methods (in which emissions inventories are compiled by considering factors such as fossil fuel use), it is clear that accurate and independent verification of these estimates will be vital if such treaties are to be successful. Here I propose to address this issue through the development the first system that can determine emissions of all of the most damaging non-carbon dioxide LLGHGs: methane, nitrous oxide, chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), halons, perfluorocarbons (PFCs) and sulfur hexafluoride (SF6). Together they account for one third of mankind's contribution to the 'greenhouse effect'. A new modelling system is proposed for the determination of LLGHG emissions using atmospheric measurements. The method will use two complementary models to maximise the information that can be extracted from the measurements by allowing emissions to be derived at high resolution close to monitoring locations and low resolution further from them. Because of the unique combination of models and techniques in this system it will be possible, for the first time, to derive emissions of all of the above LLGHGs simultaneously, allowing mutually-beneficial information to be shared between the fields being determined. The two most important non-CO2 LLGHGs, methane and nitrous oxide, will require special attention in the proposed 'inversion'. These gasses differ from the majority of LLGHGs in that they have large, but very uncertain, natural components. Their year-to-year variability has been the subject of much debate and their likely future growth is very poorly understood. To further our understanding of the behaviour of these gasses, I will employ new techniques in collaboration with partners at the Swiss Federal Institute for Forest, Snow and Landscape Research and Massachusetts Institute of Technology: parameter estimation of a state-of-the-art wetland methane emissions model, and the incorporation of the first high-frequency isotopologue measurements of nitrous oxide into the proposed model framework. The proposed research will provide a unique opportunity to answer one of the most important questions in modern atmospheric chemistry: what is the concentration and variability of the hydroxyl radical? This is a key question because the hydroxyl radical is the single largest 'cleaner' of pollutants from the atmosphere. The novel multi-species inversion outlined in this proposal will allow much tighter constraints to be placed on this quantity, providing vital information with which to test future models of atmospheric chemistry and transport, and to predict how the lifetimes of LLGHGs may change in the future. The outcomes of this proposal will be the most accurate and comprehensive emissions estimates of all non-CO2 LLGHGs currently available, an increase in our fundamental understanding of methane and nitrous oxide source partitioning and variability, and a greater knowledge of the behaviour of the hydroxyl radical. These aims are recognised as being particularly important to the evaluation of the UK Climate Change Act (2008), and as such DECC and DEFRA will provide letters of support. The understanding gained from the proposed work, and the techniques developed, will pave the way towards international treaty verification for these important greenhouse gasses.