Rashin ƙarfi na duniya

Dimming na duniya shine raguwar yawan hasken rana da ke kaiwa saman duniya. Yana haifar da kwayoyin halitta na yanayi, galibi sulfate aerosols, waɗanda ke da abubuwan gurɓata iska. An lura da dimming na duniya ba da daɗewa ba bayan a fara auna tsarin hasken rana a cikin shekarun 1950. Wannan raunanawar hasken rana mai ganuwa ya ci gaba da kashi 4-5% a kowace shekara goma har zuwa shekarun 1980.  A cikin waɗannan shekarun, gurɓataccen iska ya karu saboda masana'antu bayan yaƙi. Ayyukan hasken rana ba su bambanta fiye da yadda aka saba a wannan lokacin ba.  

Aerosols suna da tasirin sanyaya a kan yanayin duniya, kuma dimming na duniya ya rufe girman dumamar duniya da aka samu har zuwa yau, tare da yankunan da suka fi gurbatawa har ma da fuskantar sanyaya a cikin shekarun 1970s. Rashin ƙarfi na duniya ya tsoma baki tare da sake zagayowar ruwa ta hanyar rage evaporation, kuma saboda haka mai yiwuwa ya rage ruwan sama a wasu yankuna. Wataƙila ya raunana Monsoon na Kudancin Asiya kuma ya sa duk belin ruwan sama na wurare masu zafi ya koma kudu tsakanin shekara ta 1950 da shekarar 1985, tare da iyakantaccen farfadowa daga baya. Matsayi na rikodin gurɓataccen ƙwayoyin cuta a Arewacin Hemisphere ya haifar ko aƙalla ya kara tsananta gazawar ruwan sama a bayan yunwar Habasha ta shekarar 1984.

.Tun daga shekarun 1980, raguwar gurɓataccen iska ya haifar da koma baya na yanayin dimming, wani lokaci ana kiranta da haskaka duniya.[1] Wannan haske na duniya ya ba da gudummawa ga haɓakar ɗumamar yanayi, wanda ya fara a cikin 1990s.[1][2] Dangane da ƙirar yanayi, tasirin iska mai yuwuwa yana raguwa a kusa da 0.5 °C (0.90 °F) na ɗumama kamar na 2021.[3] Yayin da al'ummomi ke kokarin rage yawan gurbacewar iska ga lafiyar 'yan kasarsu, ana sa ran tasirin da ake samu kan dumamar yanayi zai kara raguwa.[4] Yanayin yanayin yanayin da ake buƙata don saduwa da 1.5 °C (2.7 °F) da 2 °C (3.6 °F) sun haɗa da raguwar matakan da ake hasashen aerosol.[3] Koyaya, samfuran simintin tasirin iska akan tsarin yanayi sun kasance marasa tabbas.[5][6] ..

Hanyoyin da ke bayan dimming na duniya suna kama da allurar aerosol ta stratospheric. Wannan wani shiri ne na aikin injiniya na hasken rana wanda ke da niyyar magance dumamar duniya ta hanyar sakin aerosols masu nunawa da gangan. Allurar Stratospheric aerosol na iya zama mai tasiri sosai wajen dakatar da ko juyar da zafi amma kuma zai sami tasiri sosai a kan sake zagayowar ruwa na duniya, yanayin yanki, da tsarin halittu. Bugu da ƙari, dole ne a gudanar da shi tsawon ƙarni don hana dawowar zafi da sauri.

## Tarihi

A cikin shekarun 1970s, bincike da yawa sun nuna cewa aerosols na yanayi na iya shafar yaduwar hasken rana ta hanyar yanayi, ma'auni wanda aka fi sani da hasken rana kai tsaye. Ɗaya daga cikin binciken ya nuna cewa karancin hasken rana yana tacewa a tsawo na    sama da Los Angeles, har ma a waɗancan kwanakin da babu hayaki mai ganuwa. Wani ya ba da shawarar cewa gurɓataccen sulfate ko fashewar dutsen wuta na iya haifar da farkon zamanin kankara.   A cikin shekarun 1980s, Atsumu Ohmura, mai binciken ilimin ƙasa a Cibiyar Fasaha ta Tarayyar Switzerland, ya gano cewa hasken rana da ke mamaye farfajiyar Duniya ya ragu da fiye da 10% a cikin shekaru talatin da suka gabata, koda kuwa zafin duniya yana ƙaruwa tun daga shekarun 1970s.   A cikin shekarun 1990s, wannan ya biyo bayan takardun da ke kwatanta raguwar shekaru goma a Estonia, Jamus, Isra'ila da kuma fadin tsohuwar Tarayyar Soviet.

Bincike na gaba ya kiyasta matsakaicin raguwar hasken rana da ke mamaye duniya na kusan 4-5% a kowace shekara goma a ƙarshen 1950s-1980s, da 2-3% a kowace shekara ta goma lokacin da aka haɗa shekarun 1990. Musamman, hasken rana a saman yanayi bai bambanta da fiye da 0.1-0.3% a duk wannan lokacin ba, yana nuna cewa dalilan da suka haifar da duhu sun kasance a Duniya. Bugu da ƙari, kawai haske mai ganuwa da radiation na infrared sun ɓace, maimakon ɓangaren ultraviolet na bakan. Bugu da ƙari, dimming ya faru ko da lokacin da sararin samaniya ya bayyana, kuma a zahiri ya fi karfi fiye da lokacin kwanakin girgije, yana tabbatar da cewa ba canje-canje a cikin girgije kadai ba ne suka haifar da shi.

## Dalilan da suka haifar

### Sulfates na mutum

Rashin haske na duniya ya samo asali ne daga kasancewar barbashi na sulfate wanda ke rataye a cikin Yanayin duniya a matsayin aerosols. Wadannan aerosols suna da gudummawa kai tsaye ga dimming, yayin da suke nuna hasken rana kamar ƙananan madubai. Har ila yau, suna da tasiri na kai tsaye a matsayin ƙwayoyin, ma'ana cewa ɗigon ruwa a cikin girgije suna haɗuwa a kusa da barbashi. Ƙarin gurɓataccen yanayi yana haifar da ƙarin ƙwayoyin cuta kuma ta haka ne ya haifar da girgije wanda ya ƙunshi adadi mafi girma na ƙananan ɗigon ruwa (watau, adadin ruwa iri ɗaya ya bazu a kan ƙarin ɗigon ruwa). Ƙananan ɗigon ruwa suna sa girgije ya fi nunawa, don haka ƙarin hasken rana mai shigowa ya sake nunawa cikin sararin samaniya kuma ƙasa ya kai saman duniya. A cikin samfuran, waɗannan ƙananan ɗigon ruwa suna rage ruwan sama.

Kafin Juyin Juya Halin Masana'antu, babban tushen sulfate aerosols shine dimethyl sulfide wanda wasu nau'ikan plankton na teku suka samar. Rashin fitarwa daga aikin dutsen wuta shine tushen na biyu mafi girma, kodayake manyan fashewar dutsen wuta, kamar fashewar Dutsen Pinatubo na shekarar 1991, sun mamaye a cikin shekarun da suka faru. A cikin shekara ta  1990, Rahoton Bincike na Farko na IPCC ya kiyasta fitar da dimethyl sulfide a tan miliyan 40 a kowace shekara, yayin da aka kiyasta fitarwa daga dutsen wuta a tan miliyan 10. Wadannan matakan shekara-shekara sun kasance masu tsayayya na dogon lokaci. A gefe guda, fitar da sulfur a duniya ya karu daga kasa da tan miliyan 3 a kowace shekara a 1860 zuwa tan miliyan 15 a shekarar 1900, tan miliyan 40 a 1940 da kuma kimanin tan miliyan 80 a 1980. Wannan yana nufin cewa a shekara ta 1980, hayakin da mutum ya haifar daga ƙone man fetur mai dauke da sulfur (yawanci kwal da Man fetur na bunker) ya zama akalla babba kamar *duk* hayakin halitta na mahaɗan da ke dauke da sulfuru. Rahoton ya kuma kammala cewa "a cikin yankuna masu masana'antu na Turai da Arewacin Amurka, hayakin da aka samo daga mutum ya mamaye hayakin halitta da kusan kashi goma ko ma fiye".&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

### Black carbon

Wani muhimmin nau'in aerosol shine baƙar carbon, wanda aka fi sani da soot. An kafa shi ne saboda ƙonewar da ba ta cika ba na burbushin burbushin halittu, da kuma itace da sauran abubuwan shuke-shuke. A duniya, mafi girman tushen baƙar fata shine daga ciyawa da gobarar daji, gami da gobarar da aka yi da gangan. Koyaya, amfani da kwal yana da alhakin mafi yawan (60 zuwa 80%) na fitar da carbon baƙar fata a Asiya da Afirka, yayin da konewar diesel ke samar da 70% na carbon baƙar jiki a Turai da Amurka.

Black carbon a cikin ƙananan yanayi shine babban mai ba da gudummawa ga mutuwar mutane miliyan 7 da suka faru ta hanyar gurɓata iska a kowace shekara. Kasancewarsa tana bayyane musamman, kamar yadda ake kira "girgije mai launin ruwan kasa" ya bayyana a wuraren da aka gurbata sosai. A zahiri, bincike ne na Shekarun 1970s a cikin girgije mai launin ruwan kasa na Denver wanda ya fara gano cewa ƙwayoyin carbon baƙar fata suna shan ƙarfin hasken rana don haka zasu iya shafar adadin hasken rana mai ganuwa. Bincike daga baya ya gano cewa baƙar fata carbon yana da sau 190 mafi tasiri wajen shan hasken rana a cikin girgije fiye da ƙura ta yau da kullun daga ƙwayoyin ƙasa. A mafi muni, duk girgije a cikin yanayin yanayi mai kauri 3-5   suna da duhu sosai, kuma gashin zai iya kaiwa ga sikelin transcontinental  (watau Girgije mai launin ruwan kasa na Asiya.) Duk da haka, gabaɗaya dimming daga baƙar fata carbon ya fi ƙasa da wannan daga ƙwayoyin sulfate. 
 

Bayan Shekara ta 1990, yanayin ƙarancin duniya ya sauya zuwa haskakawa na duniya. Wannan ya biyo bayan matakan da aka dauka don yaki da gurɓataccen iska da Kasashe masu tasowa suka dauka, yawanci ta hanyar shigar da iskar gas a tashoshin wutar lantarki, kamar su rigar rigar ko konewar gado. A Amurka, sulfate aerosols sun ragu sosai tun shekara ta 1970 tare da wucewar Dokar Tsabtace Ruwa, wanda aka ƙarfafa a shekarar 1977 da Shekara ta 1990. A cewar EPA, daga shekara ta 1970 zuwa shekarar  2005, jimlar hayaki na manyan gurɓataccen iska guda shida, gami da sulfates, ya ragu da kashi 53% a Amurka. A shekara ta 2010, wannan raguwar gurɓataccen sulfate ya haifar da kimanta kuɗin kiwon lafiya wanda ya kai dala biliyan 50 a kowace shekara. An dauki irin wannan matakai a Turai,  kamar Yarjejeniyar Helsinki ta shekarar 1985 kan Rage Sulfur Emissions a karkashin Yarjejeniyar kan Long-Range Transboundary Air Pollution, kuma tare da irin wannan ci gaba. &nbsp;

A gefe guda, wani bita na shekarar 2009 ya gano cewa dimming ya ci gaba da karuwa a kasar Sin bayan ya daidaita a cikin shekarun 1990s kuma ya kara karfi a Indiya, daidai da ci gaba da masana'antu, yayin da Amurka, Turai, da Koriya ta Kudu suka ci gaba da haskakawa. Shaidu daga Zimbabwe, Chile da Venezuela sun kuma nuna karuwar raguwa a wannan lokacin, duk da cewa a matakin amincewa mafi ƙaranci saboda ƙananan abubuwan lura. Bincike daga baya ya gano cewa a kan kasar Sin, yanayin da ke raguwa ya ci gaba da raguwa bayan 1990,  kuma bai fara juyawa ba har sai a kusa da shekara ta 2005.  Saboda wadannan bambance-bambance, babu wani canji mai mahimmanci da ya faru a duniya daga shekara ta 2001 zuwa shekarar 2012. Binciken bayan 2010 ya nuna cewa raguwar duniya a cikin maida hankali ga aerosol da dimming na duniya sun ci gaba, tare da kula da gurɓataccen yanayi a Masana'antar sufuri ta duniya da ke taka muhimmiyar rawa a cikin 'yan shekarun nan. Tun da kusan kashi 90% na yawan mutane suna zaune a Arewacin Hemisphere, girgije da ke akwai sun fi shafar aerosols fiye da Kudancin Hemispher, amma waɗannan bambance-bambance sun ragu a cikin shekaru ashirin tun daga shekara ta  2000, suna ba da ƙarin shaida ga ci gaba da haskaka duniya.

## Dangantaka da canjin yanayi

### Rashin sanyaya daga sulfate aerosols

Aerosols suna da tasirin sanyaya, wanda ya rufe jimlar yanayin zafi na duniya da aka samu har zuwa yau.

An fahimci na dogon lokaci cewa duk wani tasiri a kan hasken rana daga aerosols zai shafi Ma'aunin radiation na duniya. An riga an lura da raguwar yanayin yanayi bayan manyan fashewar dutse kamar fashewar Dutsen Agung a Bali a shekarar 1963, fashewar El Chichón a Mexico, fashewar Nevado del Ruiz a Colombia da fashewar Mount Pinatubo a Philippines a  Shekara ta 1991. Koyaya, har ma da manyan fashewar suna haifar da tsalle-tsalle na ɗan lokaci na ƙwayoyin sulfur, ba kamar karuwar da ta haifar da gurɓataccen mutum ba.

A cikin  shekara ta 1990, Rahoton Bincike na Farko na IPCC ya yarda cewa "Aerosols da aka yi da mutum, daga sulfur da aka fitar da shi da yawa a cikin konewar man fetur na iya canza girgije kuma wannan na iya aiki zuwa rage yanayin zafi", yayin da "a iya sa ran raguwar hayaki na sulfur don kara yawan yanayin duniya". Koyaya, rashin bayanan lura da matsaloli wajen lissafin tasirin kai tsaye akan girgije ya bar rahoton ba zai iya kimanta ko jimlar tasirin duk anthropogenic aerosols akan zafin duniya ya kai ga sanyaya ko dumama ba. A shekara ta 1995, Rahoton Bincike na Biyu na IPCC ya amince da tasirin tasirin aerosols gaba ɗaya a matsayin mara kyau (mai sanyaya);  duk da haka, an gane aerosols a matsayin babbar tushen rashin tabbas a cikin tsinkaye na gaba a cikin wannan rahoton da na gaba. 

### Warming daga baƙar fata carbon
Ba kamar gurɓataccen sulfate ba, baƙar carbon yana ba da gudummawa ga ƙarancin duniya da dumama na duniya, tunda barbashi suna shan hasken rana da zafi maimakon nuna shi. Wadannan barbashi kuma suna samar da murfin murfi a tsawon lokaci, wanda zai iya kara yawan shafar farko har zuwa 40%. Saboda yawan da aka kafa waɗannan sutura ya bambanta dangane da lokacin, dumama daga baƙar fata carbon ya bambanta da yanayi.

Kodayake wannan dumama ya fi rauni fiye da dumama da aka haifar da  ko sanyaya daga sulfates,  yana iya zama muhimmiyar yanki lokacin da aka sanya carbon baƙar fata a kan kan kankara kamar dutsen kankara da kankara na Greenland. A can, yana rage albedo kuma yana ƙara yawan ƙwaƙwalwar hasken rana, wanda ke hanzarta narkewar su. Black carbon kuma yana da gudummawa mai yawa ga dumama cikin gida a cikin biranen da aka gurbata. Ko da tasirin kai tsaye na barbashi na soot da ke aiki a matsayin ƙwayoyin girgije ba su da ƙarfi don samar da sanyaya: an san "girgije mai launin ruwan kasa" da aka kafa a kusa da barbashi na su da tasirin dumama tun daga shekarun 2000. Black carbon gurɓata yana da ƙarfi sosai a kan Indiya: don haka, an dauke shi ɗaya daga cikin yankuna kalilan inda tsaftace gurɓataccen iska zai rage, maimakon ƙaruwa, dumama.

### Ƙananan rawar da jirgin sama ke takawa

Jirgin sama yana barin abubuwan da ake gani (wanda aka fi sani da hanyoyin tururi) yayin da suke tafiya. Wadannan ƙwayoyin suna nuna hasken rana mai shigowa da tarkon hasken rana wanda ke fitowa daga Duniya. Saboda contrails suna nuna hasken rana kawai a rana, amma kama zafi rana da dare, galibi ana ɗaukar su don haifar da dumama, duk da cewa ƙananan ne. Kimanin 1992 ya kasance tsakanin 3.5 mW / m2 da 17 mW / mm2 - daruruwan sau karami fiye da tilasta radiative daga manyan iskar gas.&nbsp;&nbsp;

Koyaya, wasu masana kimiyya sun yi jayayya cewa tasirin sanyaya na rana daga contrails ya fi ƙarfin fiye da yadda aka kiyasta, kuma wannan gardamar ta ja hankalin mutane bayan Hare-haren Satumba 11. Saboda babu jirgin sama na kasuwanci da ya tashi a fadin Amurka nan da nan bayan hare-haren, an dauki wannan lokacin a matsayin ainihin zanga-zangar duniya na yanayin da ba shi da iska. A cikin Tashoshin yanayi 4,000 a cikin nahiyar Amurka, bambancin zafin jiki na rana (bambanci a cikin manyan da ƙananan rana a tashar da aka ɗora) an faɗaɗa shi da  ° C (2.0 ° F) - mafi girman ƙaruwa da aka rubuta a cikin shekaru 30. A kudancin Amurka, bambancin ya ragu da kimanin  ° C (6 ° F), kuma da  ° C (5 ° F) a tsakiyar yammacin Amurka. Wasu masana kimiyya sun fassara wannan a matsayin hujja na tasirin sanyaya mai karfi na jirgin sama.

### Historical cooling

A saman ƙarancin duniya, sulfur dioxide ya sami damar magance yanayin dumama gaba ɗaya. A shekara ta , ci gaba da karuwa na iskar gas din ya shawo kan tasirin rufewa, kuma sun mamaye tun daga lokacin. Ko da a lokacin, yankuna masu yawan Sulfate aerosols saboda gurɓataccen iska sun fara samun sanyaya, ya sabawa yanayin dumama gaba ɗaya. Gabashin Amurka sanannen misali ne: yanayin zafi a can ya ragu da  ° C (1.3 ° F) tsakanin 1970 da 1980, kuma har zuwa 1 ° C (1.8 ° F) a cikin Arkansas da Missouri.

### Haskakawa da hanzarin dumama
Tun daga shekarun 1980s, raguwar dimming na duniya ya ba da gudummawa ga yanayin zafi na duniya. matsanancin zafi ya hanzarta yayin da ƙarancin duniya ya ragu. An kiyasta cewa tun daga tsakiyar shekarun 1990, yawan yanayin zafi na yau da kullun a arewa maso gabashin Asiya da kwanakin zafi na shekara a Yammacin Turai za su kasance da sanyi sosai idan maida hankali ga aerosol ya kasance kamar yadda yake a baya. Wasu daga cikin hanzarin hauhawar matakin teku, da kuma karuwar Arctic da raguwar kankara na teku na Arctic, an kuma danganta su da raguwar rufewar aerosol.

A Turai, raguwar yawan aerosol tun daga shekarun  sun kuma haze hazo, hazo da hauka: gabaɗaya, yana da alhakin kusan 10-20% na dumama na rana a duk faɗin Turai, da kuma kusan 50% na dumama a kan mafi gurɓataccen Gabashin Turai. Saboda sanyaya aerosol ya dogara da nuna hasken rana, ingantaccen iska yana da tasiri mara kyau a yanayin zafi na hunturu, amma ya karu da yanayin zafi daga Afrilu zuwa Satumba da kusan 1 ° C (1.8 ° F) a Tsakiya da Gabashin Turai. Tsakiyar Amurka da gabashin Amurka sun sami dumama na  ° C (0.54 ° F) tsakanin 1980 da 2010 yayin da aka rage gurɓataccen sulfate,  koda kuwa ƙwayoyin sulfate har yanzu suna da kusan kashi 25% na dukkan ƙwayoyin.  A shekara ta 2021, gabar arewa maso gabashin Amurka ta kasance ɗaya daga cikin yankuna masu saurin dumama na Arewacin Amurka, yayin da raguwar Atlantic Meridional Overturning Circulation ya kara yawan zafin jiki a wannan ɓangaren Tekun Atlantika.

A cikin shekara ta  2020, kullewar COVID-19 ta samar da sanannen "gwaji na halitta", saboda an sami raguwar sulfate da baƙar fata na carbon wanda ya haifar da raguwar zirga-zirgar hanya da fitar da masana'antu. Wannan raguwa yana da tasirin dumama mai ganowa: an kiyasta cewa ya karu da yanayin zafi na duniya da 0.01-0.02 ° C (0.018- ° F) da farko kuma har zuwa 0.03 ° C (0.054 ° F) ta 2023, kafin ya ɓace. A cikin yanki, an kiyasta kullewar don kara yawan zafin jiki da 0.05-0.15   a gabashin China a cikin Janairu-Maris, sannan da 0.04-0.07   akan Turai, gabashin Amurka, da Kudancin Asiya a watan Maris-Mayu, tare da tasirin    na wasu yankuna na Amurka da Rasha. A cikin birnin Wuhan, an gano tasirin tsibirin zafi na birane ya ragu da  ° C (0.43 ° F) da dare kuma da 0.12 ° C (0.22 ° F) gabaɗaya yayin makullin da ya fi tsananin.

### Makomar nan gaba
Tun da canje-canje a cikin maida hankali na aerosol sun riga sun yi tasiri a kan yanayin duniya, dole ne su rinjayi tsinkaye na gaba. A zahiri, ba zai yiwu a kimanta tasirin dumama na duk iskar gas ba tare da lissafin maganin sanyaya daga aerosols ba.

Misalai na yanayi sun fara lissafin tasirin sulfate aerosols a kusa da Rahoton Bincike na Biyu na IPCC; lokacin da aka buga Rahoton Bishara na Huɗu na IPCC a cikin shekara ta 2007, kowane samfurin yanayi yana da sulfates, amma 5 ne kawai suka iya lissafin ƙananan ƙwayoyin kamar baƙar fata. Yazo a shekarar 2021, samfuran CMIP6 sun kiyasta jimlar sanyaya aerosol a cikin kewayon daga  ° C ( ° F) zuwa  ° C (1.3 ° F);  Rahoton Bincike na shida na IPCC ya zaɓi mafi kyawun ƙididdigar sanyaya  ° C (0.90 ° F) da sulfate aerosols suka bayar, yayin da baƙar carbon ya kai kusan 0.1   na dumama. Duk da yake waɗannan dabi'u sun dogara ne akan haɗakar ƙididdigar samfurin tare da ƙuntatawa na lura, gami da waɗanda ke kan abubuwan zafi na teku,  ba a riga an daidaita batun ba. Bambanci tsakanin ƙididdigar samfurin ya samo asali ne daga rashin jituwa game da tasirin kai tsaye na aerosols akan girgije.

Regardless of the current strength of aerosol cooling, all future climate change scenarios project decreases in particulates and this includes the scenarios where  and  targets are met: their specific emission reduction targets assume the need to make up for lower dimming. Since models estimate that the cooling caused by sulfates is largely equivalent to the warming caused by atmospheric methane (and since methane is a relatively short-lived greenhouse gas), it is believed that simultaneous reductions in both would effectively cancel each other out.
 Yet, in the recent years, methane concentrations had been increasing at rates exceeding their previous period of peak growth in the 1980s, with wetland methane emissions driving much of the recent growth, while air pollution is getting cleaned up aggressively. These trends are some of the main reasons why  warming is now expected around 2030, as opposed to the mid-2010s estimates where it would not occur until 2040.

An kuma ba da shawarar cewa ba a ba da isasshen kulawa a cikin ƙididdigar haɗarin yanki ba, duk da kasancewa da tasiri a kan sikelin yanki fiye da duniya. Misali, Yanayin canjin yanayi tare da hayakin iskar gas mai yawa amma raguwa mai ƙarfi a gurɓataccen iska zai ga  ° C (0.36 ° F) ƙarin dumamar duniya nan da shekarar 2050 fiye da wannan yanayin tare da ɗan ingantaccen ingancin iska, amma a yanki, bambancin zai ƙara ƙarin dare 5 na wurare masu zafi a kowace shekara a arewacin China kuma ya karu da hazo a arewacin Indiya. Hakazalika, takarda da ke kwatanta matakin yanzu na manufofin iska mai tsabta tare da matsakaicin aikin da za a iya amfani da shi a karkashin in ba haka ba Yanayin canjin yanayi ya gano cewa wannan na ƙarshe zai kara haɗarin matsanancin zafin jiki da 30-50% a China da Turai.

Abin takaici, saboda tarihin aerosols sun fi ƙanƙanta a wasu yankuna fiye da wasu, daidaitattun tsinkaye na yanki na tasirin aerosol yana da wahala. Ko da sabbin samfuran yanayi na CMIP6 na iya wakiltar yanayin aerosol a Turai,  amma gwagwarmaya da wakiltar Arewacin Amurka da Asiya. Wannan yana nufin cewa tsinkayen su na kusan nan gaba na tasirin yanki na iya ƙunsar kurakurai.

## Dangantaka da sake zagayowar ruwa
 

A kan yanki da kuma duniya, gurɓataccen iska na iya shafar sake zagayowar ruwa, a hanyar da ta yi kama da wasu matakai na halitta. Ɗaya daga cikin misalai shine tasirin ƙura Sahara akan tsarin guguwa: iska da ke cike da yashi da ma'adanai yana motsawa a kan Tekun Atlantika, inda suke toshe wasu Hasken rana daga isa saman ruwa, dan kadan yana sanyaya shi kuma yana rage ci gaban guguwa. Hakazalika, an ba da shawarar tun farkon shekarun 2000 cewa tun lokacin da aerosols ke rage hasken rana a kan teku kuma saboda haka suna rage evaporation daga gare ta, za su "juyawa cikin sake zagayowar ruwa na duniya".

A cikin shekara ta 2011, an gano cewa anthropogenic aerosols sun kasance babban abin da ya haifar da canje-canje na karni na 20 a cikin ruwan sama a kan sashin Tekun Atlantika,  lokacin da duk belin ruwan sama na wurare masu zafi ya koma kudu tsakanin shekarun 1950 da shekarar 1985, tare da iyakance canjin arewa daga baya.  Ana sa ran raguwa a cikin fitar da iska a nan gaba zai haifar da saurin canji zuwa arewa, tare da iyakantaccen tasiri a cikin Atlantic amma tasiri mafi girma a cikin Pacific. Wasu bincike sun kuma nuna cewa waɗannan raguwa za su shafi AMOC (wanda ake sa ran ya raunana saboda canjin yanayi). Ragewa daga manufofi masu ingancin iska masu ƙarfi na iya kara wannan raguwar da ake tsammani da kusan 10%, sai dai idan an rage hayakin methane da adadin daidai.

Mafi mahimmanci, nazarin da yawa sun haɗa aerosols daga Arewacin Hemisphere zuwa rashin nasarar ruwan sama a yankin Sahara a cikin shekarun 1970 da shekarar 1980, wanda ya haifar da fari na Sahel da yunwa mai alaƙa.   Koyaya, ƙirar samfurin yanayin Sahel ba daidai ba ne, don haka yana da wahala a tabbatar da cewa fari ba zai faru ba tare da gurɓataccen iska ba, kodayake a bayyane zai kasance ba mai tsanani ba. Wasu bincike sun nuna cewa waɗancan samfuran da ke nuna dumama kadai da ke haifar da karuwar hazo mai ƙarfi a cikin Sahel sune mafi daidaito, suna mai da shi mai yiwuwa cewa gurɓataccen sulfate ne ya zargi don mamaye wannan martani da aika yankin cikin fari.

Wani binciken ban mamaki ya haɗa tasirin aerosols tare da raunanawar Monsoon na Kudancin Asiya. An fara ci gaba a shekara ta 2006,  duk da haka ya kasance da wahala a tabbatar da shi.  Musamman, wasu bincike sun ba da shawarar cewa dumama kanta tana ƙara haɗarin gazawar ruwan sama, mai yuwuwar tura shi zuwa wani wuri mai tsawo. A shekara ta 2021, duk da haka, an kammala cewa dumamar duniya ta ci gaba da ƙarfafa ruwan sama, kuma an riga an lura da wasu ƙarfafawa bayan raguwar aerosol da aka haifar.

A shekara ta 2009, wani bincike na shekaru 50 na bayanai ya gano cewa ruwan sama mai sauƙi ya ragu a gabashin China, kodayake babu wani canji mai mahimmanci a yawan ruwan da ke cikin yanayi. An danganta wannan ga aerosols rage girman droplet a cikin girgije, wanda ya haifar da waɗancan girgije riƙe ruwa na dogon lokaci ba tare da ruwan sama ba. Abubuwan da ke faruwa na aerosols da ke hana ruwan sama ta hanyar rage girman ruwan sama an tabbatar da su ta hanyar binciken da ya biyo baya. Bincike daga baya ya gano cewa gurɓataccen aerosol a Kudancin da Gabashin Asiya ba kawai ya hana ruwan sama a can ba, amma kuma ya haifar da ƙarin danshi da aka canja zuwa Asiya ta Tsakiya, inda ruwan sama na rani ya karu a sakamakon haka. A cikin Amurka, tasirin canjin yanayi a kan sake zagayowar ruwa yawanci zai kara yawan ruwan sama da matsanancin ruwan sama a duk faɗin ƙasar, amma waɗannan tasirin sun kasance "masked" ta hanyar bushewa saboda yawan aerosol mai ƙarfi a tarihi. Rahoton Bincike na shida na IPCC ya kuma danganta canje-canje a cikin maida hankali ga canjin hazo a yankin Bahar Rum.

## Muhimmancin injiniyan hasken rana

Rashin ƙarfi na duniya yana da mahimmanci ga wasu shawarwari game da jinkirta, dakatar da, ko juyar da dumamar duniya. Karin albedo na duniya na 1% zai kawar da mafi yawan tilasta radiative daga hayakin gas mai ɗumi na mutum kuma ta haka ne dumama duniya, yayin da karuwar albedo na 2% zai hana tasirin dumama na ninka yawan carbon dioxide na yanayi. Wannan shine ka'idar da ke bayan gyaran radiation na rana (ko geoengineering na hasken rana), kuma babban damar nunawa na sulfate aerosols yana nufin cewa an dauke su a cikin wannan damar tun daga shekarun 1970s.

Saboda matakan tarihi na dimming na duniya suna da alaƙa da babban mutuwa daga gurɓataccen iska da batutuwan kamar ruwan sama na acid, an bayyana manufar dogaro da sanyaya kai tsaye daga gurɓatawa a matsayin "sadarwar Faustian" kuma ba a la'akari da shi sosai ta hanyar bincike na zamani ba. Maimakon haka, takarda mai mahimmanci na  shekarar 2006 na Paul Crutzen ya ba da shawarar cewa hanyar da za a guje wa karuwar dumama yayin da gurɓataccen sulfate ya ragu shi ne sake duba shawarar  a shekara ta 1974 ta mai binciken Soviet Mikhail Budyko. Shirin ya haɗa da sakin sulfates daga jiragen sama da ke tashi a saman sararin samaniya, a cikin abin da yanzu aka bayyana a matsayin allurar aerosol ta stratospheric, ko SAI. Idan aka kwatanta, mafi yawan gurɓataccen iska yana cikin ƙananan yanayi (troposphere), kuma yana zaune a can kawai na makonni. Saboda aerosols da aka ajiye a cikin stratosphere zai kasance na tsawon shekaru, dole ne a fitar da ƙaramin sulfur don samar da adadin sanyaya iri ɗaya.

Duk da yake shawarar farko ta Crutzen ta mayar da hankali kan kauce wa dumama da ya haifar da raguwar gurɓataccen iska, nan da nan an fahimci cewa haɓaka wannan shawarar na iya jinkirta, dakatar, ko juyawa dumama. An kiyasta cewa adadin sulfur da ake buƙata don daidaitawar dumama na kusan 4 ° C (7.2 ° F) dangane da yanzu (da 5 ° C (9.0 ° F) dangi ga preindustrial), a ƙarƙashin yanayin fitarwa mafi girma RCP 8.5 zai zama ƙasa da abin da aka riga aka fitar ta hanyar gurɓata iska a yau, kuma cewa raguwar gurɓataccen sulfur daga ingantaccen iska na gaba da aka riga an sa ran a ƙarƙashin wannan yanayin zai sa sulfur da aka yi amfani da shi don geoengineering. Kasuwancin yana ƙara farashi. Kodayake akwai wani sanannen labari cewa mutane, ƙananan jihohi, ko wasu 'yan wasan da ba na jihar ba za su iya aiwatar da allurar aerosol ta stratospheric, ƙididdigar kimiyya ta nuna cewa sanyaya yanayi da 1 ° C (1.8 ° F) ta hanyar allurar aérospheric zai kashe akalla dala biliyan 18 a kowace shekara (a darajar USD 2020), ma'ana cewa kawai manyan tattalin arziki ko tubalan tattalin arziki zasu iya samun wannan shiga tsakani. Duk da haka, waɗannan hanyoyin za su kasance "dokokin girman" mafi arha fiye da rage iskar gas,  ba tare da farashin tasirin canjin yanayi ba. &nbsp;

Ko da SAI ta dakatar ko kuma ta juya yanayin zafi na duniya, yanayin yanayi a wurare da yawa zai canza sosai. Gidan  da sauran cututtukan cututtuka zasu canza. Koyaya, ba a san yadda zai kwatanta da sauye-sauyen da za su iya faruwa daga canjin yanayi ba. Ƙananan hasken rana zai shafi amfanin gona da sinks na carbon saboda rage photosynthesis, amma wannan zai iya ragewa ta hanyar rashin damuwa daga dumama da kuma tasirin takin CO mafi girma dangane da yanzu. Mafi mahimmanci, dumama daga hayaki na CO2 yana da ɗaruruwan zuwa dubban shekaru, yayin da sanyaya daga SAI ya tsaya shekaru 1-3 bayan allurar aerosol ta ƙarshe. Wannan yana nufin cewa ba za a iya amfani da allurar aerosol na stratospheric ko wasu nau'ikan geoengineering na hasken rana a matsayin maye gurbin rage hayakin gas. Sabanin haka, idan matakan iskar gas sun kasance masu girma, zai haifar da "babban da sauri" zafi da kuma irin wannan sauye-sauye na kwatsam ga sake zagayowar ruwa. Dubban nau'o'in halittu za su iya ɓacewa a sakamakon haka. Maimakon haka, duk wani aikin injiniya na hasken rana zai yi aiki a matsayin matakin wucin gadi don iyakance dumama. A lokaci guda, ana rage hayaki na iskar gas kuma An cire carbon dioxide, wanda zai iya ɗaukar daruruwan shekaru.

## Dubi kuma

* Global cooling - An yi watsi da ra'ayi na shekarun 1970 na sanyaya duniya da ke gabatowa
* Global stilling - Rage saurin iska kusa da farfajiyar DuniyaShafuka da ke nuna taƙaitaccen bayanin manufofi
* Impact winter - Sakamakon yanayi da aka yi la'akari da shi saboda tasirin asteroid ko comet a Duniya
* Nuclear winter - Tasirin yanayi na yaki na nukiliya
* Volcanic winter - Abubuwan da suka faru na yanayin zafi wanda ya haifar da fashewar dutse
* Pyranometer - Kayan aiki don auna hasken rana
* Ship tracks - Girgije da ke kewaye da hayaki da jiragen ruwa suka fitar
* Sunshine recorders - Kayan aiki na yanayiShafuka da ke nuna taƙaitaccen bayanin manufofi

## Manazarta

## Haɗin waje

* Shirin Aerosol na Duniya