VOA科学技术2023 臭氧层开始缓慢"愈合"（在线收听）

A United Nations report has found that Earth's protective ozone layer is slowly healing itself.

联合国发布的一份报告称，保护地球的臭氧层正在缓慢自愈。

Ozone is a form of oxygen.

臭氧是氧气的一种形式。

In Earth's upper atmosphere, it acts as a barrier to block harmful radiation from the sun.

在地球的上层大气中，它起到了阻挡太阳有害辐射的作用。

But closer to Earth's surface, ozone is a common pollutant.

但在更靠近地球表面的地方，臭氧是一种常见的污染物。

At ground level, high levels of ozone can harm people's lungs and damage plants.

在地面上，高浓度的臭氧会损害人们的肺部和植物。

Research has shown that chemical pollutants released into the atmosphere shrink the ozone layer over time.

研究表明，随着时间的推移，释放到大气中的化学污染物会使臭氧层缩小。

The layer exists in a part of Earth's atmosphere known as the stratosphere.

臭氧层是指地球大气层的平流层中的一部分。

The layer sits between 15 to 30 kilometers above Earth's surface.

臭氧层位于地球表面上方15至30公里处。

Each year, a large hole develops in the layer over Antarctica.

每年，南极洲上空都会出现一个大洞。

In their new report, U.N. scientists say at the current rate, the ozone hole over Antarctica would be fully healed by 2066.

联合国科学家在他们的新报告中称，按照目前的速度，南极洲上空的臭氧层空洞将会在2066年完全愈合。

Paul Newman is the co-chair of the U.N. report.

保罗·纽曼担任这份联合国报告联合主席。

It was recently presented at a meeting of the American Meteorological Society.

该报告最近在美国气象学会的一次会议上发表。

He told The Associated Press, "In the upper stratosphere and in the ozone hole we see things getting better."

他告诉美联社：“我们发现平流层上层和臭氧层空洞中的情况正在好转。”

However, the researchers reported the healing is happening very slowly.

然而，研究人员报告称，愈合速度非常缓慢。

The worldwide average amount of ozone is estimated to return to pre-thinning levels around 2040, the report said.

报告称，据估计，全球平均臭氧量将会在2040年左右恢复到变薄前的水平。

A 1987 agreement called the Montreal Protocol banned a series of chemicals – mainly used in refrigerants and aerosols – believed to have reduced the thickness of the ozone layer.

1987年签署的《蒙特利尔议定书》禁止使用一系列化学物质——主要用于制冷剂和气雾剂——据信这些化学物质减小了臭氧层的厚度。

The Secretary-General of the World Meteorological Organization, Petteri Taalas, commented about the report in a statement.

世界气象组织秘书长佩特里·塔拉斯在一份声明中评论了这份报告。

He said past actions taken to reduce ozone damage had demonstrated the importance of limiting climate-harming substances.

他说，过去为减少臭氧破坏所采取的行动已经证明了限制危害气候的物质的重要性。

Newman added that while signs of healing were reported four years ago, researchers were looking for more lasting change.

纽曼还说，虽然四年前就有报告称臭氧层有自愈的迹象，但研究人员当时正在寻找更持久的变化。

The earlier recovery numbers had "solidified a lot," he said.

他说，之前的恢复数据“巩固了很多”。

The two main chemicals that eat away at ozone are in lower levels in the atmosphere, said Newman, who is also the chief Earth scientist at NASA's Goddard Space Flight Center.

纽曼也是美国航空航天局戈达德太空飞行中心的首席地球科学家，他说，侵蚀臭氧层的两种主要化学物质在大气中的含量较低。

The report said chlorine levels were down 11.5 percent since they reached a high in 1993.

报告称，氯含量自1993年达到最高水平以来下降了11.5%。

Bromine – which does a better job of eating ozone but exists at lower levels in the air – dropped 14.5 percent since reaching a high point in 1999.

溴对臭氧层的破环作用更大，但溴在空气中的含量较低，自1999年达到峰值以来下降了14.5%。

Newman said the reductions in chlorine and bromine levels came largely because of the limits set in the Montreal Protocol.

纽曼说，氯和溴含量的降低在很大程度上是因为《蒙特利尔议定书》规定的限制。

Another member of the research team was David W. Fahey, director of the U.S. National Oceanic and Atmospheric Administration's chemical sciences lab.

该研究小组的另一名成员是美国国家海洋和大气管理局化学科学实验室主任戴维·法希。

He said the latest results show there has been a "sea change" in the way the world deals with its ozone-thinning substances.

他说，最新的研究结果表明，世界在处理致使臭氧层变薄的物质的方式上发生了“翻天覆地的变化”。

Natural weather cycles in the Antarctic also affect ozone hole levels, which are highest in the autumn.

南极的自然天气周期也会影响臭氧层空洞的臭氧含量，臭氧层空洞中的臭氧含量在秋季最高。

The past few years, Newman said, the ozone hole grew a bit bigger because of that.

纽曼说，在过去的几年里，臭氧层空洞因此而变得更大。

But overall, the results demonstrate clear healing, the report said.

但报告称，总体而言，结果显示，臭氧层在明显愈合。

I'm Bryan Lynn.

布莱恩·林恩为您播报。