A pilot programme to measure the South Asian outflow of ozone depleting substances and greenhouse gases

我们将制定一项方案，从马尔代夫气候观测站-Hanimaadhoo（MCOH）测量温室气体和消耗臭氧层物质，该观测站拦截南亚流出的污染空气。南亚是世界上的一个重要地区，迄今为止，从未对许多主要痕量气体进行过常规测量，例如将在这里测量的卤烃。我们将在烧瓶中收集空气并分析它们，以获得在高级全球大气气体实验（AGAGE）中测量的全套约50种合成卤代烃气体。我们将估计南亚的氯氟烃（CFCs）、氢氯氟烃（HCFCs）和氢氟碳化合物（HFCs）排放量，这些化合物受国际《关于消耗臭氧层物质的蒙特利尔议定书》管制。氟氯化碳是一种强效消耗臭氧层物质，在世界各地广泛用于制冷、空调和发泡。根据《蒙特利尔议定书》，全球禁止生产和使用氟氯化碳。作为回应，工业界转而使用被称为氟氯烃的替代化合物。虽然氟氯烃对臭氧层的破坏比氟氯化碳小，但它仍然具有破坏臭氧层的特性。因此，氟氯烃随后受到《蒙特利尔议定书》的管制，但发展中国家仍被允许排放氟氯烃，并逐步淘汰。氟氯烃的替代品是氢氟碳化合物，它不会消耗臭氧，但却是强效温室气体。为了减少它们对气候的影响，《蒙特利尔议定书》为氢氟碳化合物的生产和使用设定了一个逐步减少的时间表，许多国家的削减要到2024年才开始。我们的研究将使我们能够确定2021-2022年南亚的CFC，HCFC和HFC排放量，并评估MCOH在监测南亚卤化碳污染物流出方面的适用性，以便在该地点实施长期测量。

We will develop a programme to measure greenhouse gases (GHGs) and ozone depleting substances (ODSs) from the Maldives Climate Observatory-Hanimaadhoo (MCOH), which intercepts the outflow of polluted air from South Asia. South Asia is an important region of the world that, to date, has never had routine measurement of many major trace gases such as the halocarbons that will be measured here. We will collect air in flasks and analyse them for the full suite of ~50 synthetic halocarbon gases measured in the Advanced Global Atmospheric Gases Experiment (AGAGE). We will estimate South Asia's emissions of the chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs), the compounds regulated by the international Montreal Protocol on Substances that Deplete the Ozone Layer. CFCs are potent ODSs that were used widely around the world for refrigeration, air-conditioning and foam blowing. Production and use of CFCs have been banned globally under the Montreal Protocol. In response, industries switched to replacement compounds known as HCFCs. While less damaging to the ozone layer than CFCs, HCFCs still have ozone destruction properties. Thus, HCFCs were subsequently regulated under the Montreal Protocol but developing countries are still permitted to emit HCFCs with a gradual phase-out. The replacements for HCFCs are HFCs, which do not deplete ozone but are potent GHGs. To reduce their impact on climate, the Montreal Protocol set a phase-down schedule for HFC production and use - with cuts in many countries not beginning until 2024. Our study will allow us to determine South Asia's emissions of CFCs, HCFCs and HFCs over 2021-2022 and to assess the suitability of MCOH in monitoring the outflow of halocarbon pollutants from South Asia so that long-term measurements can be implemented at this site.