Raguwar ozone

Ragewar Ozone ya ƙunshi abubuwa biyu masu alaƙa da aka gani tun daga ƙarshen 1970s: an saukar da jimlar adadin ozone a sararin samaniyar duniya, da kuma raguwar lokacin bazara mai yawa a cikin sararin samaniyar ozone (layin ozone) a kusa da yankunan polar duniya."Twenty Questions and Answers About the Ozone Layer" (PDF). Scientific Assessment of Ozone Depletion: 2010. World Meteorological Organization. 2011. Archived (PDF) from the original on 2013-03-05. Retrieved March 13, 2015 Lamarin na ƙarshe ana kiransa da rami na ozone. Har ila yau, akwai abubuwan da suka faru na raguwar yanayin yanayi na lokacin bazara ban da waɗannan abubuwan da suka faru na stratospheric.

Babban abubuwan da ke haifar da raguwar ozone da ramin ozone sune sunadarai da aka ƙera, musamman masana'anta na halocarbon refrigerants, abubuwan kaushi, furotin, da abubuwan busa kumfa (chlorofluorocarbons (CFCs), HCFCs, halons), waɗanda ake magana da su a matsayin abubuwa masu ragewa ozone (ODS).Gruijl, Frank de; Leun, Jan (October 3, 2000). "Environment and health: 3. Ozone depletion and ultraviolet radiation". CMAJ. 163 (7): 851–855. PMC 80511. PMID 11033716 – via www.cmaj.ca.. Ana shigar da waɗannan mahadi zuwa cikin stratosphere ta hanyar gaurayawan hargitsi bayan an fitar da su daga saman, suna haɗuwa da sauri fiye da yadda kwayoyin za su iya daidaitawa.Andino, Jean M. (October 21, 1999). "Chlorofluorocarbons (CFCs) are heavier than air, so how do scientists suppose that these chemicals reach the altitude of the ozone layer to adversely affect it ?". Scientific American. 264: 68. Da zarar a cikin stratosphere, suna saki atom daga rukunin halogen ta hanyar rarraba hoto, wanda ke haifar da rushewar ozone (O3) zuwa oxygen (O2).[4]. Dukkan nau'ikan raunin ozone an lura suna karuwa yayin da hayakin halocarbons ya karu.

Ragewar Ozone da ramin ozone sun haifar da damuwa a duniya game da karuwar haɗarin ciwon daji da sauran mummunan tasiri. Layin ozone yana hana illar raƙuman hasken ultraviolet (UVB) wucewa ta cikin yanayin duniya. Wadannan tsawon igiyoyin suna haifar da ciwon daji na fata, kunar rana, makanta na dindindin, da cataracts, [5] waɗanda aka yi hasashen za su ƙaru sosai sakamakon raguwar ozone, da cutar da tsirrai da dabbobi. Wadannan damuwa sun haifar da amincewa da yarjejeniyar Montreal a 1987, wanda ya hana samar da CFCs, halons, da sauran sinadarai masu lalata ozone.[6] A tsawon lokaci, masana kimiyya sun haɓaka sabbin na'urori masu sanyi tare da ƙarancin dumamar yanayi (GWP) don maye gurbin tsofaffi. Misali, a cikin sabbin motoci, tsarin R-1234yf yanzu sun zama gama gari, ana zabar su akan firigeren da ke da GWP mafi girma kamar R-134a da R-12.

Haramcin ya fara aiki a cikin 1989. Matakan Ozone ya daidaita a tsakiyar 1990s kuma ya fara farfadowa a cikin 2000s, yayin da motsi na jet a kudancin kogin zuwa kudancin kudu ya tsaya kuma yana iya komawa.[7]. An yi hasashen farfadowar zai ci gaba a cikin karni na gaba, tare da ramin ozone da ake sa ran zai kai matakin kafin 1980 a kusa da 2075.[8] A cikin 2019, NASA ta ba da rahoton cewa rami na ozone shine mafi ƙanƙanta tun lokacin da aka fara gano shi a cikin 1982.[9][10] Majalisar Dinkin Duniya a yanzu tana aiwatar da cewa a karkashin ka'idojin na yanzu tsarin ozone zai sake farfadowa gaba daya nan da 2045.[11][12] Ana ɗaukar ka'idar Montreal yarjejeniya mafi nasara ta muhalli ta duniya har zuwa yau.[13][14]

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