一些国家仍非法使用氯氟碳化合物(含氯氟烃)禁止。>”2018年,高水平的禁止氯氟化碳在大气中被发现,最终被追踪到中国”的其他原因包括[气候变化][1]。>大气中的有害物质的浓度趋于平稳自协议生效和正在慢慢减少,提供层逐渐愈合的基础。但现在日益恶化的气候变化减缓经济复苏。> >虽然在地球表面温度增加,平流层,保护臭氧层所在,冷却下来。平流层,地球大气层的层6.5到30英里(10到50公里)的高度,就是所谓的极地平流层云形式在冬天。今天科学家们知道,这些云提供完美的化学环境有害的氯和要知道他们的破坏性的工作物质。他们也知道冷平流层的温度,极地平流层云越倾向于形式。> >“有时臭氧空洞很小,因为没有极地平流层云,有时,当有很多,它往往是更大的。”"With more polar stratospheric clouds, chlorine and other harmful substances can work more effectively and cause more damage even if their concentrations are decreasing." As a [further explanation][2], > Halogenated ODS are effectively inert in the lower atmosphere. The overturning motions associated with warming and cooling of airmasses in the lower atmosphere allows some of the ODS to be transported into the stratosphere. The substances are then broken down by ultraviolet light and form stable halogenated “reservoir” compounds, which by themselves do not strongly affect ozone. > >The main problem arises when the reservoir compounds are further altered to create halogenated “reactive” radicals. This is done through processes that largely take place on the surfaces of tiny stratospheric aerosol particles. These reactions make the by-products of the ODS more potent for ozone destruction. > >The amount of particles taking part in this process is significantly enhanced in Antarctica over winter. This is because of the presence of Polar Stratospheric Clouds (PSCs) in the lower stratosphere. > > > PSCs are made up of tiny particles made up primarily of nitric acid and water vapour, and require a temperature of around -80°C or colder to form. In winter, a vortex of air forms in the stratosphere over Antarctica. Within the vortex, air circulates with minimal mixing with the rest of the atmosphere. This drives strong cooling of the lower stratosphere and creates the conditions favourable for PSC formation. > >When spring comes, the halogens released by the PSCs are broken down by sunlight. The resulting free chlorine and bromine atoms destroy ozone before being cycled back into halogen radicals. The presence of sunlight begins the cycle again. > >Overall, the reaction cycle destroys many ozone molecules for each chlorine and bromine atom present. PSC formation enhances the cycle as it removes certain nitrogen compounds from the atmosphere. These compounds would otherwise reduce the overall amount of halogenated radicals present. **The [latest opinion][3], is that,** > while the ozone layer is beginning to recover, it's likely to take until the 2060s for the ozone-depleting substances used in refrigerants and spray cans to completely disappear from the atmosphere. [1]: https://www.space.com/giant-ozone-hole-antarctica-climate-change [2]: https://theconversation.com/explainer-what-is-the-antarctic-ozone-hole-and-how-is-it-made-9202 [3]: https://www.abc.net.au/news/2021-09-17/earth-ozone-layer-hole-larger-than-antarctica/100469328