Fitar da sifili

Fitar da sifili shine gajarta gama gari na sifili da sifili na shekara-shekara na iskar gas mai gurbata yanayi. Yana nufin cewa, a cikin tsawon shekara guda, hayakin da mutane ke haifarwa yana daidaita daidai gwargwado ta hanyar nutsewar greenhouse da mutane ke yi. ’Yan Adam ba su haifar da wani canji ba, a tsawon wannan shekarar, ga sakamakon dumamar yanayi na iskar gas a cikin yanayin duniya. Sau da yawa ana rage fitar da sifili zuwa sifili.

Fitar da iska na iya komawa ga duk iskar gas ko carbon dioxide (CO2) kawai.Fankhauser, Sam; Smith, Stephen M.; Allen, Myles; Axelsson, Kaya; Hale, Thomas; Hepburn, Cameron; Kendall, J. Michael; Khosla, Radhika; Lezaun, Javier; Mitchell-Larson, Eli; Obersteiner, Michael; Rajamani, Lavanya; Rickaby, Rosalind; Seddon, Nathalie; Wetzer, Thom (2022). "The meaning of net zero and how to get it right". Nature Climate Change. 12 (1): 15–21. Bibcode:2022NatCC..12...15F. doi:10.1038/s41558-021-01245-w. Samun sifilin sifili yana da mahimmanci don dakatar da ƙarin dumamar yanayi. Yana buƙatar raguwa mai zurfi a cikin hayaƙi, misali ta hanyar canzawa daga mai zuwa makamashi mai dorewa, inganta ingantaccen makamashi da dakatar da sare bishiyoyi. Za a iya kashe ɗan ƙaramin juzu'in da ya rage na hayaki ta amfani da cirewar carbon dioxide.

Mutane sukan yi amfani da kalmomin da ke fitar da sifili, tsaka tsaki na carbon, da tsaka tsaki na yanayi tare da ma'ana iri ɗaya. Misali, wasu ma'auni don takaddun shaida na tsaka tsaki na carbon suna ba da izinin kashe carbon da yawa. Amma ma'auni na sifili yana buƙatar rage fitar da hayaki zuwa fiye da 90% sannan sai a kashe ragowar kashi 10% ko ƙasa da haka don faɗuwa daidai da maƙasudan 1.5 °C."A Beginner's Guide to Climate Neutrality". United Nations Climate Change. 26 February 2021. Retrieved 2023-08-20. Kungiyoyi galibi suna kashe ragowar hayakinsu ta hanyar siyan kuɗin carbon.

A farkon 2020 net zero ya zama babban tsarin aikin sauyin yanayi. Kasashe da kungiyoyi da yawa suna kafa maƙasudin sifili. Ya zuwa Nuwamba 2023, kusan ƙasashe 145 sun ba da sanarwar ko kuma suna yin la'akari da manufofin sifiri, wanda ke rufe kusan kashi 90% na hayaƙin duniya. Sun haɗa da wasu ƙasashe waɗanda suka yi tsayayya da ayyukan sauyin yanayi a shekarun da suka gabata. Makasudin sifili na matakin ƙasa yanzu ya ƙunshi kashi 92% na GDP na duniya, kashi 88% na hayaƙi, da kashi 89% na yawan al'ummar duniya. 65% na manyan kamfanoni 2,000 na jama'a da aka yi ciniki ta hanyar kudaden shiga na shekara suna da maƙasudin sifili. Daga cikin kamfanoni na Fortune 500, kashi 63%. Makasudin kamfani na iya haifar da ayyukan sa kai da kuma ka'idojin gwamnati.

Da'awar sifili ta yanar gizo ta bambanta da yawa ta yadda ake sahihanci, amma yawancin suna da ƙarancin aminci duk da karuwar alƙawura da maƙasudi.More companies setting 'net-zero' climate targets, but few have credible plans, report says". AP News. 11 June 2023. Retrieved 31 July 2023. Yayin da kashi 61 cikin 100 na hayakin carbon dioxide na duniya ana rufe su da wani nau'in manufa na sifili, maƙasudai masu inganci sun rufe kashi 7% kawai na hayaƙi. Wannan ƙarancin amincin yana nuna rashin ƙa'idar ɗaurewa. Haka kuma saboda bukatar ci gaba da kirkire-kirkire da saka hannun jari don sanya fitar da iskar gas ta yiwu.

Ya zuwa yanzu, kasashe 27 sun kafa dokar sifiri na cikin gida. Waɗannan dokoki ne waɗanda ke ɗauke da maƙasudin sifili ko makamancin haka. A halin yanzu babu wata ƙa'ida ta ƙasa da ke buƙatar kamfanoni masu tushe a cikin ƙasar don cimma sifiri. Duk da haka ƙasashe da yawa, misali Switzerland, suna haɓaka irin wannan doka.Solomon, Susan; Plattner, Gian-Kasper; Knutti, Reto; Friedlingstein, Pierre (2009-02-10). "Irreversible climate change due to carbon dioxide emissions". Proceedings of the National Academy of Sciences. 106 (6): 1704–1709. Bibcode:2009PNAS..106.1704S. doi:10.1073/pnas.0812721106. ISSN 0027-8424. PMC 2632717. PMID 19179281

 Tarihi da hujjar kimiyya 
Tunanin sifirin sifiri ya fito ne daga bincike a ƙarshen 2000s game da yadda yanayi, tekuna da sake zagayowar carbon ke amsawa ga hayaƙin CO2. Wannan bincike ya gano cewa dumamar yanayi zai tsaya ne kawai idan aka rage hayakin CO2 zuwa sifili. Sifili ne mai mahimmanci ga manufofin yarjejeniyar Paris. Wannan ya bayyana cewa dole ne duniya ta "cimma ma'auni tsakanin hayakin bil'adama ta hanyar tushe da kuma kawar da iskar gas a cikin rabin na biyu na wannan karni". The term "net zero" gained popularity after the Intergovernmental Panel on Climate Change published its Special Report on Global Warming of 1.5 °C (SR15) in 2018, this report stated that "Reaching and sustaining net zero global anthropogenic [human-caused] CO2 emissions and declining net non-CO2 radiative forcing would halt anthropogenic global warming on multi-decadal timescales (high aminci)." 

Tunanin fitar da sifili sau da yawa yana rikicewa tare da "kwantar da yawan iskar iskar gas a cikin yanayi", kalma daga Yarjejeniyar Rio ta 1992. Hanyoyi biyun ba iri daya bane. Wannan shi ne saboda sake zagayowar carbon ya ci gaba da yin sequesters ko kuma ɗaukar ɗan ƙaramin yanki na yanayi na CO2 da ɗan adam ke haifarwa zuwa ciyayi da teku, ko da bayan iskar CO2 ta ragu zuwa sifili. Idan an rage fitar da CO2 daga ayyukan ɗan adam zuwa sifili, ƙaddamar da CO2 a cikin yanayi zai ragu. Wannan zai kasance a cikin saurin isa don rama jinkirin ɗumamar zurfin teku. Sakamakon zai kasance kusan matsakaicin matsakaicin yanayin yanayin duniya na tsawon shekaru da yawa ko ƙarni. Sabanin haka, daidaita yanayin yanayi na CO₂ zai ba da damar wasu hayaki mai gudana, amma yanayin zafi na duniya zai ci gaba da hauhawa tsawon ƙarni da yawa saboda jinkirin martanin teku ga dumamar yanayi.The Net-Zero Standard". Science Based Targets. Retrieved 20 June 2023.

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