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    聯合國表示,臭氧空洞有望在50年內修復

    聯合國表示,臭氧空洞有望在50年內修復

    Seth Borenstein, 美聯社 2023-01-12
    長期以來,全球各地的科學家和環保人士一直認為,各國為修復臭氧空洞于1987年簽訂的《蒙特利爾議定書》是人類在維護生態方面最大的勝利之一。

    聯合國(United Nations)的一份新報告稱,地球的臭氧層正在緩慢“愈合”,按照當前速度,南極洲上方的空洞有望在43年內完全消失。

    該修復進程由四年一次的科學評估發現,此時距全球各國一致同意停止生產會侵蝕大氣中臭氧層的化學物質已經過去35年。臭氧層能夠為地球防護有害輻射,避免人們罹患皮膚癌、白內障等疾病以及農作物損失。

    “在平流層上層和臭氧空洞中,我們看到情況正在好轉?!笨茖W評估聯合主席保羅·紐曼表示。

    今年1月9日在丹佛舉行的美國氣象學會(American Meteorological Society)大會上發表的報告顯示,臭氧空洞縮小進展緩慢。報告稱,離地球表面18英里(約28.97千米)的臭氧平均含量要到2040年左右才可以恢復到1980年變稀薄之前的水平。北極地區到2045年才會恢復正常。

    報告稱,南極洲的臭氧層已經極為稀薄,每年都會出現巨大的空洞,要到2066年才能夠完全恢復正常。

    長期以來,全球各地的科學家和環保人士一直認為,各國為修復臭氧空洞于1987年簽訂《蒙特利爾議定書》(Montreal Protocol),約定禁止生產常用于制冷劑和噴霧劑的化學物質,這是人類在維護生態方面最大的勝利之一。

    “臭氧治理為氣候行動樹立了先例。逐步淘汰破壞臭氧的化學品方面獲得的成功充分顯示了,情況緊迫時可以做些什么以及怎樣做,才能夠逐漸淘汰化石燃料,降低溫室氣體排放,限制氣溫上升?!笔澜鐨庀蠼M織(World Meteorological Organization)的秘書長彼得里·塔拉斯教授在一份聲明中表示。

    四年前就已經出現修復的跡象,但當時跡象尚不明顯且偏初步階段?!叭缃褡C明臭氧恢復的數據穩定了很多?!奔~曼說。

    紐曼也是美國國家航空航天局戈達德太空飛行中心(NASA’s Goddard Space Flight Center)的首席地球科學家,他表示,大氣中破壞臭氧的兩種主要化學物質含量有所降低。報告稱,氯含量自1993年達到峰值以來下降了11.5%,而破壞臭氧更嚴重的溴比1999年峰值減少了14.5%。

    大氣中溴和氯含量“停止增長并逐步下降,充分證明了《蒙特利爾議定書》的作用?!奔~曼表示。

    “全社會處理破壞臭氧物質的方式發生了巨大變化?!泵绹鴩液Q蠛痛髿夤芾砭郑║.S. National Oceanic and Atmospheric Administration)化學科學實驗室主任、科學小組聯合主席大衛·W·費伊說。

    費伊稱,幾十年前人們隨便去商店就可以買到會破壞臭氧的制冷劑,導致臭氧空洞還污染大氣?,F在,相關物質不僅禁止銷售,人們家里或汽車上也幾無留存,取而代之的是更清潔的化學制劑。

    南極的自然氣候模式也會影響臭氧空洞狀況,一般秋季空洞規模最大。紐曼指出,過去幾年受自然氣候影響空洞規模還有所擴大,但總體仍然保持縮小趨勢。

    這一趨勢“每年能夠避免200萬人罹患皮膚癌?!苯衲暝缧r候,聯合國環境規劃署(United Nations Environment Programme)的署長英格·安德森在一封電子郵件里對美聯社(The Associated Press)表示。

    幾年前,被禁的化學物質之一——氯氟烴-11(CFC-11)排放量停止降低并轉為增加。紐曼說,因為中國部分地區發現了排放,現在已經降回預期水平。

    幾年前,第三代化學物質含氫氟烴被禁止使用,原因并不是會破壞臭氧層,而是因為含氟氯烴是吸熱的溫室氣體。新研究報告稱,該禁令可以避免溫度再升高0.5度至0.9度(0.3攝氏度至0.5攝氏度)。

    報告還警告道,如果向大氣中加入噴霧劑反射陽光從而人為冷卻地球,就將導致南極洲的臭氧層減少20%。(財富中文網)

    美聯社的氣候和環境報道獲得了幾家私人基金會的支持。美聯社對所有內容負責。

    譯者:梁宇

    審校:夏林

    聯合國(United Nations)的一份新報告稱,地球的臭氧層正在緩慢“愈合”,按照當前速度,南極洲上方的空洞有望在43年內完全消失。

    該修復進程由四年一次的科學評估發現,此時距全球各國一致同意停止生產會侵蝕大氣中臭氧層的化學物質已經過去35年。臭氧層能夠為地球防護有害輻射,避免人們罹患皮膚癌、白內障等疾病以及農作物損失。

    “在平流層上層和臭氧空洞中,我們看到情況正在好轉?!笨茖W評估聯合主席保羅·紐曼表示。

    今年1月9日在丹佛舉行的美國氣象學會(American Meteorological Society)大會上發表的報告顯示,臭氧空洞縮小進展緩慢。報告稱,離地球表面18英里(約28.97千米)的臭氧平均含量要到2040年左右才可以恢復到1980年變稀薄之前的水平。北極地區到2045年才會恢復正常。

    報告稱,南極洲的臭氧層已經極為稀薄,每年都會出現巨大的空洞,要到2066年才能夠完全恢復正常。

    長期以來,全球各地的科學家和環保人士一直認為,各國為修復臭氧空洞于1987年簽訂《蒙特利爾議定書》(Montreal Protocol),約定禁止生產常用于制冷劑和噴霧劑的化學物質,這是人類在維護生態方面最大的勝利之一。

    “臭氧治理為氣候行動樹立了先例。逐步淘汰破壞臭氧的化學品方面獲得的成功充分顯示了,情況緊迫時可以做些什么以及怎樣做,才能夠逐漸淘汰化石燃料,降低溫室氣體排放,限制氣溫上升?!笔澜鐨庀蠼M織(World Meteorological Organization)的秘書長彼得里·塔拉斯教授在一份聲明中表示。

    四年前就已經出現修復的跡象,但當時跡象尚不明顯且偏初步階段?!叭缃褡C明臭氧恢復的數據穩定了很多?!奔~曼說。

    紐曼也是美國國家航空航天局戈達德太空飛行中心(NASA’s Goddard Space Flight Center)的首席地球科學家,他表示,大氣中破壞臭氧的兩種主要化學物質含量有所降低。報告稱,氯含量自1993年達到峰值以來下降了11.5%,而破壞臭氧更嚴重的溴比1999年峰值減少了14.5%。

    大氣中溴和氯含量“停止增長并逐步下降,充分證明了《蒙特利爾議定書》的作用?!奔~曼表示。

    “全社會處理破壞臭氧物質的方式發生了巨大變化?!泵绹鴩液Q蠛痛髿夤芾砭郑║.S. National Oceanic and Atmospheric Administration)化學科學實驗室主任、科學小組聯合主席大衛·W·費伊說。

    費伊稱,幾十年前人們隨便去商店就可以買到會破壞臭氧的制冷劑,導致臭氧空洞還污染大氣?,F在,相關物質不僅禁止銷售,人們家里或汽車上也幾無留存,取而代之的是更清潔的化學制劑。

    南極的自然氣候模式也會影響臭氧空洞狀況,一般秋季空洞規模最大。紐曼指出,過去幾年受自然氣候影響空洞規模還有所擴大,但總體仍然保持縮小趨勢。

    這一趨勢“每年能夠避免200萬人罹患皮膚癌?!苯衲暝缧r候,聯合國環境規劃署(United Nations Environment Programme)的署長英格·安德森在一封電子郵件里對美聯社(The Associated Press)表示。

    幾年前,被禁的化學物質之一——氯氟烴-11(CFC-11)排放量停止降低并轉為增加。紐曼說,因為中國部分地區發現了排放,現在已經降回預期水平。

    幾年前,第三代化學物質含氫氟烴被禁止使用,原因并不是會破壞臭氧層,而是因為含氟氯烴是吸熱的溫室氣體。新研究報告稱,該禁令可以避免溫度再升高0.5度至0.9度(0.3攝氏度至0.5攝氏度)。

    報告還警告道,如果向大氣中加入噴霧劑反射陽光從而人為冷卻地球,就將導致南極洲的臭氧層減少20%。(財富中文網)

    美聯社的氣候和環境報道獲得了幾家私人基金會的支持。美聯社對所有內容負責。

    譯者:梁宇

    審校:夏林

    Earth’s protective ozone layer is slowly but noticeably healing at a pace that would fully mend the hole over Antarctica in about 43 years, a new United Nations report says.

    A once-every-four-years scientific assessment found recovery in progress, more than 35 years after every nation in the world agreed to stop producing chemicals that chomp on the layer of ozone in Earth’s atmosphere that shields the planet from harmful radiation linked to skin cancer, cataracts and crop damage.

    “In the upper stratosphere and in the ozone hole we see things getting better,” said Paul Newman, co-chair of the scientific assessment.

    The progress is slow, according to the report presented on January9 at the American Meteorological Society convention in Denver. The global average amount of ozone 18 miles (30 kilometers) high in the atmosphere won’t be back to 1980 pre-thinning levels until about 2040, the report said. And it won’t be back to normal in the Arctic until 2045.

    Antarctica, where it’s so thin there’s an annual giant gaping hole in the layer, won’t be fully fixed until 2066, the report said.

    Scientists and environmental advocates across the world have long hailed the efforts to heal the ozone hole — springing out of a 1987 agreement called the Montreal Protocol that banned a class of chemicals often used in refrigerants and aerosols — as one of the biggest ecological victories for humanity.

    “Ozone action sets a precedent for climate action. Our success in phasing out ozone-eating chemicals shows us what can and must be done – as a matter of urgency — to transition away from fossil fuels, reduce greenhouse gases and so limit temperature increase,” World Meteorological Organization Secretary-General Prof. Petteri Taalas said in a statement.

    Signs of healing were reported four years ago but were slight and more preliminary. “Those numbers of recovery have solidified a lot,” Newman said.

    The two chief chemicals that munch away at ozone are in lower levels in the atmosphere, said Newman, chief Earth scientist at NASA’s Goddard Space Flight Center. Chlorine levels are down 11.5% since they peaked in 1993 and bromine, which is more efficient at eating ozone but is at lower levels in the air, dropped 14.5% since its 1999 peak, the report said.

    That bromine and chlorine levels “stopped growing and is coming down is a real testament to the effectiveness of the Montreal Protocol,” Newman said.

    “There has been a sea change in the way our society deals with ozone depleting substances,” said scientific panel co-chair David W. Fahey, director of the U.S. National Oceanic and Atmospheric Administration’s chemical sciences lab.

    Decades ago, people could go into a store and buy a can of refrigerants that eat away at the ozone, punch a hole in it and pollute the atmosphere, Fahey said. Now, not only are the substances banned but they are no longer much in people’s homes or cars, replaced by cleaner chemicals.

    Natural weather patterns in the Antarctic also affect ozone hole levels, which peak in the fall. And the past couple years, the holes have been a bit bigger because of that but the overall trend is one of healing, Newman said.

    This is “saving 2 million people every year from skin cancer,” United Nations Environment Programme Director Inger Andersen told The Associated Press earlier this year in an email.

    A few years ago emissions of one of the banned chemicals, chlorofluorocarbon-11 (CFC-11), stopped shrinking and was rising. Rogue emissions were spotted in part of China but now have gone back down to where they are expected, Newman said.

    A third generation of those chemicals, called HFC, was banned a few years ago not because it would eat at the ozone layer but because it is a heat-trapping greenhouse gas. The new report says that the ban would avoid 0.5 to 0.9 degrees (0.3 to 0.5 degrees Celsius) of additional warming.

    The report also warned that efforts to artificially cool the planet by putting aerosols into the atmosphere to reflect the sunlight would thin the ozone layer by as much as 20% in Antarctica.

    Associated Press climate and environmental coverage receives support from several private foundations. The AP is solely responsible for all content.

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