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Tsarin carbon shine wannan bangare na sake zagayowar biogeochemical wanda ake musayar carbon tsakanin biosphere, pedosphere, geosphere, hydrosphere, da yanayi na Duniya. Sauran manyan sake zagayowar biogeochemical sun haɗa da sake zagayolar nitrogen da sake zagaye na ruwa. Carbon shine babban bangare na mahadi na halitta da kuma babban bangare ne na ma'adanai da yawa kamar dutse. Tsarin carbon ya ƙunshi jerin abubuwan da suka faru waɗanda keda mahimmanci don sa Duniya ta iya kiyaye rayuwa. Ya bayyana motsi na carbon yayin da aka sake amfani dashi kuma aka sake amfani dashi a duk faɗin biosphere, da kuma matakai na dogon lokaci na ƙwaƙwalwar carbon (ajiyewa) zuwa da saki daga sinks na carbon.
Don bayyana yanayin sake zagayowar carbon, ana iya yin bambanci tsakanin saurin saurin sautin carbon. Ana kuma kiran sake zagayowar carbon mai sauri a matsayin sake zagayolar carbon na halitta. Saurin zagaye na carbon na iya kammalawa cikin shekaru, motsa abubuwa daga yanayi zuwa biosphere, sannan komawa cikin yanayi. Saurin ko sake zagayowar ƙasa (wanda ake kira zurfin sake zagayolar carbon) na iya ɗaukar miliyoyin shekaru don kammalawa, abubuwa masu motsi ta hanyar ɓawon burodi na Duniya tsakanin duwatsu, ƙasa, teku da yanayi.[2]
Mutane sun dame sake zagayowar carbon na ƙarni da yawa. Sunyi hakan ta hanyar canza amfani da ƙasa da kuma hakar ma'adinai da ƙone carbon daga tsoffin kayan halitta (kwal, man fetur da gas). [1] Carbon dioxide a cikin yanayi yakaru kusan 52% a kan matakan da suka gabata zuwa 2020, wanda ya haifar da dumamar duniya.[3] Karin carbon dioxide ya kuma haifar da raguwa a cikin darajar pH na teku kuma yana canza sunadarai na ruwa.[4] Carbon dioxide yana da mahimmanci ga photosynthesis.
An nuna motsi na carbon na ƙasa a cikin sake zagayowar ruwa a cikin zane a dama kuma an bayyana shi a ƙasa:
Canjin carbon tsakanin tafkuna yana faruwa ne sakamakon tsarin sunadarai, na jiki, na ƙasa, da na halitta. Tekun ya ƙunshi mafi girman tafkin carbon mai aiki kusa da farfajiyar Duniya.[5]Hanyar halitta ta carbon tsakanin yanayi, teku, yanayin halittu na ƙasa, da kuma turɓaya suna da daidaituwa sosai; don haka matakan carbon zasu kasance kusan kwanciyar hankali batare da tasirin ɗan adam ba.[6]
Carbon a cikin yanayin duniya yana cikin manyan siffofi guda biyu: carbon dioxide da methane. Dukkanin wadannan iskar gas suna shanyewa kuma suna riƙe da zafi a cikin yanayi kuma suna da wani bangare na alhakin tasirin greenhouse.[5] Methane yana samar da babban tasirin greenhouse a kowane girma idan aka kwatanta da carbon dioxide, amma yana cikin ƙananan maida hankali kuma yana da ɗan gajeren lokaci fiye da carbon dioxide. Don haka, carbon dioxide yana ba da gudummawa ga tasirin greenhouse na duniya fiye da methane.[8]
Ana cire carbon dioxide daga yanayi da farko ta hanyar photosynthesis kuma ya shiga cikin yanayin ƙasa da na teku. Har ila yau, carbon dioxide yana narkewa kai tsaye daga yanayi zuwa cikin ruwa (teku, tabkuna, da dai sauransu), kazalika da narkewa cikin hazo yayin da ruwan sama yafadi ta cikin yanayi. Lokacin da aka narke a cikin ruwa, carbon dioxide yana amsawa tare da kwayoyin ruwa kuma yana samar da carbonic acid, wanda ke bada gudummawa ga acidity na teku. Sa'an nan kuma duwatsu zasu iya shawo kansa ta hanyar yanayi. Hakanan yana iya yin acid a wasu wurare da ya taɓa ko kuma a wanke shi cikin teku.[9]
Ayyukan ɗan adam a cikin ƙarni biyu da suka gabata sun ƙara adadin carbon a cikin yanayi da kusan kashi 50% tun daga shekara ta 2020, galibi a cikin nau'in carbon dioxide, duka ta hanyar canza ikon yanayin halittu don cire carbon dioxide daga yanayi da kuma fitar dashi kai tsaye, misali, ta hanyar ƙone burbushin burbushin halittu da ƙera kankare.[3][5] A nan gaba mai nisa (shekaru biliyan 2 zuwa 3), yawan da ake shan carbon dioxide a cikin ƙasa ta hanyar sake zagayowar carbonate-silicate zai iya ƙaruwa saboda canje-canjen da ake tsammani a cikin rana yayin da yake tsufa. Ƙarin hasken rana da ake tsammani zai iya hanzarta yawan yanayin ƙasa.[10] Wannan zai haifar da mafi yawan carbon dioxide a cikin sararin samaniya ya shiga cikin ɓawon burodi na Duniya a matsayin carbonate.[11][12] Da zarar maida hankali ga carbon dioxide a cikin yanayi yafaɗi ƙasa da kusan kashi 50 a kowace miliyan (haƙuri ya bambanta tsakanin jinsuna), C<sub id="mwjg">3</sub> photosynthesis bazai yiwu ba.[13] Anyi hasashen wannan zai faru shekaru miliyan 600 daga yanzu, kodayake samfuran sun bambanta.[14]
Da zarar teku a Duniya ta bushe a cikin kimanin shekaru biliyan 1.1 daga yanzu, [10] farantin tectonics zai iya tsayawa saboda rashin ruwa don shafa su. Rashin tsaunuka masu fashewa dake fitar da carbon dioxide zai haifar da sake zagayowar carbon ya ƙare tsakanin shekaru biliyan 1 zuwa biliyan 2 a nan gaba.[15]
Tsarin halittu na duniya ya haɗa da carbon na halitta a cikin dukkan kwayoyin halitta masu rai, masu rai da matattu, da kuma carbon da aka adana a cikin ƙasa. Kimanin 500 gigatons na carbon ana adana su a sama da ƙasa a cikin tsire-tsire da sauran kwayoyin halitta masu rai, yayin da ƙasa ke riƙe da kusan 1,500 gigatons of carbon. [16] Yawancin carbon a cikin yanayin halittu na ƙasa shine carbon na halitta, yayin da kusan kashi ɗaya bisa uku na carbon na ƙasa ana adana shi a cikin siffofin inorganic, kamar calcium carbonate. [17][18] Organic carbon babban bangare ne na dukkan kwayoyin dake rayuwa a duniya. Autotrophs suna cire shi daga iska a cikin nau'in carbon dioxide, suna canza shi zuwa carbon na halitta, yayin da heterotrophs ke karɓar carbon ta hanyar cinye wasu kwayoyin.
Saboda karɓar carbon a cikin yanayin halittu na ƙasa ya dogara da abubuwan da ke tattare da halittu, yana bin tsarin rana da na yanayi. A cikin ma'aunin CO2, wannan fasalin ya bayyana a cikin keeling curve. Yana da karfi a arewacin arewacin arewa saboda wannan arewacin yana da ƙasa da yawa fiye da kudancin kudancin kuma ta haka ne ƙarin wuri ga yanayin halittu don shawo kan kuma fitar da carbon.
Carbon leaves the terrestrial biosphere in several ways and on different time scales. The combustion or respiration of organic carbon releases it rapidly into the atmosphere. It can also be exported into the ocean through rivers or remain sequestered in soils in the form of inert carbon.[19] Carbon stored in soil can remain there for up to thousands of years before being washed into rivers by erosion or released into the atmosphere through soil respiration. Between 1989 and 2008 soil respiration increased by about 0.1% per year.[20] In 2008, the global total of CO2 released by soil respiration was roughly 98 billion tonnes[ana buƙatar hujja], about 3 times more carbon than humans are now putting into the atmosphere each year by burning fossil fuel (this does not represent a net transfer of carbon from soil to atmosphere, as the respiration is largely offset by inputs to soil carbon).[ana buƙatar hujja][<span title="This claim needs references to reliable sources. (April 2024)">citation needed</span>] There are a few plausible explanations for this trend, but the most likely explanation is that increasing temperatures have increased rates of decomposition of soil organic matter, which has increased the flow of CO2. The length of carbon sequestering in soil is dependent on local climatic conditions and thus changes in the course of climate change.[21]
| Ruwa | Adadin (gigatons) |
|---|---|
| Yanayi | 720 |
| Tekun (cikakken) | 38,400 |
| Cikakken inorganic | 37,400 |
| Cikakken kwayoyin halitta | 1,000 |
| Layer na sama | 670 |
| Layer mai zurfi | 36,730 |
| Lithosphere | |
| Carbonates na sedimentary | > 60,000,000 |
| Kerogens | 15,000,000 |
| Biosphere na duniya (cikakken) | 2,000 |
| Rayayyun halittu | 600 – 1,000 |
| Matattu biomass | 1,200 |
| Yanayin halittu na ruwa | 1 – 2 |
| Abubuwan da ke cikin burbushin halittu (cikakken) | 4,130 |
| Karfe | 3,510 |
| Mai | 230 |
| Gas | 140 |
| Sauran (peat) | 250 |
Za'a iya raba teku a cikin wani nau'i na sama wanda ruwa ke yin hulɗa akai-akai (kowace zuwa shekara-shekara) tare da yanayi, da kuma zurfin zurfin zurfi na mita ɗari ko ƙasa da haka, wanda lokacin tsakanin lambobin sadarwa na gaba zai iya zama ƙarni. Ana musayar carbon inorganic (DIC) da aka narke a cikin farfajiyar da sauri tare da yanayi, yana riƙe da daidaituwa. Wani bangare saboda yawan DIC ya kai kusan 15% mafi girma amma galibi saboda girmansa, teku mai zurfi ya ƙunshi carbon da yawa - shine mafi girman tafkin carbon mai aiki a duniya, wanda ke dauke da sau 50 fiye da yanayi [5] amma lokacin da zafin zai kai ga daidaito tare da yanayi shine daruruwan shekaru: musayar carbon tsakanin yadudduka biyu, wanda ke motsawa ta hanyar zagayawar thermohaline, yana da jinkiri.
Carbon ya shiga cikin teku galibi ta hanyar rushewar carbon dioxide na yanayi, karamin ɓangaren da aka canza zuwa carbonate. Hakanan yana iya shiga cikin teku ta hanyar koguna a matsayin carbon mai narkewa. Kwayoyin halitta suna canza shi zuwa carbon na kwayoyin halitta ta hanyar photosynthesis kuma ana iya musayar shi a ko'ina cikin jerin abinci ko kuma a kwashe shi cikin zurfin teku, mafi wadataccen carbon a matsayin matattu mai laushi ko a cikin harsashi kamar calcium carbonate. Yana zagayawa a cikin wannan Layer na dogon lokaci kafin a ajiye shi a matsayin laka ko, a ƙarshe, ya koma cikin ruwa ta hanyar zagayawar thermohaline.
Tekuna na asali ne (tare da Darajar pH na yanzu na 8.1 zuwa 8.2). Karin CO2 na yanayi yana canza pH na teku zuwa tsaka-tsaki a cikin tsari da ake kira acidisation na teku. Rashin CO2 na teku yana daya daga cikin mahimman nau'ikan carbon. Yawan da aka tsara na raguwar pH na iya rage saurin hazo na calcium carbonates, don haka rage ikon teku don sha CO2. [22][23]
An nuna motsi na carbon na ƙasa a cikin sake zagayowar ruwa a cikin zane a dama kuma an bayyana shi a ƙasa:
Yawancin carbon na Duniya ana adana su a cikin lithosphere na Duniya.[5] Yawancin carbon da aka adana a cikin mantle na Duniya an adana shi a can lokacin da aka kafa Duniya. Wasu daga cikinsu an ajiye su a cikin nau'in carbon na kwayoyin halitta daga biosphere.[24] Daga cikin carbon da aka adana a cikin geosphere, kusan 80% shine dutse mai laushi da abubuwan da aka samo asali, wanda ya samo asali ne daga sedimentation na calcium carbonate da aka adada a cikin kwarangwal na kwayoyin ruwa. Sauran kashi 20% ana adana su azaman kerogens da aka kafa ta hanyar sedimentation da binne kwayoyin ƙasa a ƙarƙashin zafi da matsin lamba. Kwayar carbon da aka adana a cikin geosphere na iya kasancewa a can na miliyoyin shekaru.[25]
Carbon na iya barin geosphere ta hanyoyi da yawa. Ana fitar da carbon dioxide a lokacin metamorphism na duwatsun carbonate lokacin da aka saukar dasu cikin mantle na duniya. Ana iya sakin wannan carbon dioxide a cikin yanayi da teku ta hanyar tsaunuka masu fitattun wuta da hotspots. Hakanan mutane na iya cire shi ta hanyar cirewa kai tsaye na kerogens a cikin nau'in man fetur. Bayan cirewa, ana ƙone burbushin burbushin don fitar da makamashi da fitar da carbon da suke adanawa cikin yanayi.
Akwai saurin sake zagayowar carbon. Tsarin sauri yana aiki a cikin biosphere kuma jinkirin sake zagayowar yana aiki a kan duwatsu. Tsarin sauri ko na halitta na iya cikawa cikin shekaru, yana motsa carbon daga yanayi zuwa biosphere, sannan ya koma cikin yanayi. Saurin ko sake zagayowar ƙasa na iya fadada zurfi cikin mantle kuma yana iya ɗaukar miliyoyin shekaru don kammalawa, yana motsa carbon ta cikin ɓawon duniya tsakanin duwatsu, ƙasa, teku da yanayi.[2]
The fast carbon cycle involves relatively short-term biogeochemical processes between the environment and living organisms in the biosphere (see diagram at start of article). It includes movements of carbon between the atmosphere and terrestrial and marine ecosystems, as well as soils and seafloor sediments. The fast cycle includes annual cycles involving photosynthesis and decadal cycles involving vegetative growth and decomposition. The reactions of the fast carbon cycle to human activities will determine many of the more immediate impacts of climate change.[26][27][28]
Saurin (ko zurfi) sake zagayowar carbon ya haɗa da matsakaici zuwa matakai na geochemical na dogon lokaci na cikin sake zagayolar dutse (duba zane a dama). Canjin tsakanin teku da yanayi na iya ɗaukar ƙarni, kuma yanayin duwatsu na iya ɗaukar miliyoyin shekaru. Carbon a cikin teku yana sauka zuwa ƙarƙashin teku inda zai iya samar da dutse mai laushi kuma a subducted cikin mantle na Duniya. Hanyoyin gine-ginen dutse suna haifar da dawowar wannan carbon na ƙasa zuwa farfajiyar Duniya. A can ana samun iska a kan duwatsu kuma ana mayar da carbon zuwa yanayi ta hanyar degassing da kuma teku ta koguna. Sauran carbon na geologic ya koma cikin teku ta hanyar fitar da hydrothermal na ions na calcium. A cikin shekara guda tsakanin tan miliyan 10 zuwa 100 na carbon yana motsawa a kusa da wannan jinkirin sake zagayowar. Wannan ya haɗa da tsaunuka masu fashewa da ke dawo da carbon kai tsaye zuwa yanayi a cikin nau'in carbon dioxide. Koyaya, wannan ƙasa da kashi ɗaya cikin ɗari ne na carbon dioxide da aka sanya cikin yanayi ta hanyar ƙone man fetur.[2][29]
An nuna motsi na carbon na ƙasa a cikin sake zagayowar ruwa a cikin zane a dama kuma an bayyana shi a ƙasa:
Tsarin halittu na ƙasa da na ruwa galibi ana haɗa su ta hanyar jigilar kogin, wanda ke aiki a matsayin babban tashar da abubuwan da aka samo daga ƙasa suka shiga cikin tsarin teku. Canjin kayan aiki da makamashi tsakanin Yanayin halittu na ƙasa da lithosphere da kuma tsarin carbon na kwayoyin halitta da hanyoyin oxidation tare suna tsara tsarin halittu na carbon da dioxygen (O2). [61]
Sufuri na kogi, kasancewa babbar hanyar haɗi ta waɗannan tafkuna, zatayi aiki don jigilar yawan amfanin gona na farko (da farko a cikin nau'in narkewar carbon (DOC) da carbon carbon mai ƙwayoyin cuta (POC)) daga ƙasa zuwa tsarin teku.[62] A lokacin sufuri, wani ɓangare na DOC zai dawo cikin sauri zuwa yanayi ta hanyar halayen redox, wanda ke haifar da "degasing carbon" yafaru tsakanin yadudduka na ajiyar ƙasa.[63][64] Sauran DOC da narkewar carbon inorganic (DIC) ana fitar dasu zuwa teku.[65][66][67] A cikin 2015, an kimanta yaduwar fitar da carbon na inorganic da kwayoyin halitta daga koguna na duniya a matsayin 0.50-0.70 Pg C y-1 da 0.15-0.35 Pg C da-1 bi da bi.[66] A gefe guda, POC na iya kasancewa a binne shi a cikin turɓaya a tsawon lokaci, kuma an kiyasta ƙarar duniya ta shekara-shekara zuwa teku a 0.20 (+0.13,-0.07) Gg C y−1 . [68][61]
Fump din halittu na teku shine kwacewar carbon ta teku daga yanayi da ƙasa zuwa zurfin teku da kuma zurfin teku.[69] Fump din halittu ba sakamakon tsari ɗaya ba ne, amma jimlar matakai da yawa kowannensu na iya rinjayar famfo na halittu. Fuskar tana canja wurin kimanin tan biliyan 11 na carbon a kowace shekara zuwa cikin teku. Tekun ba tare da famfo na halitta bazai haifar da matakan CO2 na yanayi game da 400 ppm sama da na yau.[70][71][72]
Yawancin carbon da aka haɗa a cikin kwayoyin halitta da kwayoyin halitta an kafa sune a saman teku inda zai iya fara nutsewa zuwa ƙarƙashin teku. Ruwa mai zurfi yana samun mafi yawan abubuwan gina jiki daga ginshiƙan ruwa mafi girma lokacin da suka nutse a cikin nau'in dusar ƙanƙara. Wannan ya kunshi dabbobi da ƙwayoyin cuta da matattu ko masu mutuwa, ƙwayoyin ƙwayoyin, yashi da sauran kayan inorganic.[73]
Fumbar halittu tana da alhakin canza narkewar carbon inorganic (DIC) zuwa kwayoyin halitta da kuma jefa shi a cikin ƙwayoyin cuta ko narkewar tsari a cikin teku mai zurfi. Inorganic nutrients da carbon dioxide suna gyara a lokacin photosynthesis ta hanyar phytoplankton, wanda duka biyu suna fitar da kwayoyin halitta (DOM) kuma zooplankton mai cin ganyayyaki ke cinye su. Babban zooplankton - kamar copepods, ƙwayoyin ƙwayoyin cuta - wanda za'a iya sake dawowa, kuma ya nutse ko ya tattara tare da wasu kayan ƙwayoyin halitta a cikin manyan abubuwa masu saurin nutsewa. DOM yana cinyewa da ƙwayoyin cuta kuma yana numfashi; sauran DOM mai ƙin yarda suna advected kuma suna gaurayewa cikin zurfin teku. DOM da abubuwan da aka fitar da su cikin ruwa mai zurfi ana cinye su kuma ana numfasawa, don haka dawo da carbon na halitta a cikin babban tafkin teku mai zurfi na DIC.[74]
Kwayar phytoplankton guda ɗaya tana da ƙimar nutsewa kusan mita ɗaya a kowace rana. Idan aka bada cewa matsakaicin zurfin teku kusan kilomita huɗu ne, zai iya ɗaukar sama da shekaru goma don waɗannan sel su isa ƙarƙashin teku. Koyaya, ta hanyar matakai irin su coagulation da fitarwa a cikin ƙwayoyin ƙwayoyin cuta, waɗannan ƙwayoyin suna samar da tarawa. Wadannan tarin suna da ƙididdigar nutsewa dayawa fiye da ƙwayoyin halitta kuma sun kammala tafiyarsu zuwa zurfi a cikin kwanaki.
Kimanin kashi 1% na barbashi dake barin teku sun kai ga zurfin teku kuma ana cinye su, numfashi, ko binne su a cikin turɓaya. Sakamakon waɗannan matakai shine cire carbon a cikin nau'in kwayoyin halitta daga farfajiya kuma mayar dashi zuwa DIC a zurfin zurfi, kiyaye yanayin teku na DIC. Yankin thermohaline ya dawo da zurfin teku DIC zuwa yanayi a kan lokutan dubban shekaru. Ana iya saukar da carbon da aka binne a cikin turɓaya a cikin mantle na duniya kuma a adana shi na miliyoyin shekaru a matsayin wani ɓangare na jinkirin sake zagayowar carbon (duba sashi na gaba). [74]
Saurin ko zurfin cycling yana da mahimmanci, kodayake ba'a fahimta sosai kamar yadda motsi na carbon mai sauri ta hanyar yanayi, yanayin ƙasa, teku, da geosphere ba.[75] Tsarin carbon mai zurfi yana da alaƙa da motsi na carbon a farfajiyar duniya da yanayi. Idan ba'a wanzu wannan tsari ba, carbon zai kasance a cikin yanayi, inda zai tara zuwa matakai masu girma a tsawon lokaci. Sabili da haka, ta hanyar bada izinin carbon ya koma Duniya, zurfin sake zagayowar carbon yana taka muhimmiyar rawa wajen kiyaye yanayin duniya da ake buƙata don rayuwa ta wanzu.
Bugu da ƙari, wannan tsari yanads mahimmanci kawai saboda yawan carbon da yake ɗauka a cikin duniyar. A zahiri, nazarin abun dake cikin basaltic Magma da auna iskar carbon dioxide daga dutsen wuta ya nuna cewa adadin carbon a cikin mantle yafi na duniya girma da kashi dubu daya.[76] Bincike da lura da matakai masu zurfin carbon na duniya a bayyane yake yana da matukar wahala, yayin da ƙananan mantle da core suka shimfiɗa daga 660 zuwa 2,891 km da 2,891 zuwa 6,371 km zurfi a cikin Duniya bi da bi. Dangane da haka, basan abubuwa da yawa game da rawar da carbon ke takawa a cikin zurfin Duniya ba. Duk da haka, shaidu da yawa - da yawa daga cikinsu sun fito ne daga gwajin dakin gwaje-gwaje na yanayin duniya mai zurfi - sun nuna hanyoyin da za su iya motsawa a cikin ƙananan mantle, da kuma siffofin da carbon ke ɗauka a matsanancin yanayin zafi da matsin lamba na wannan Layer. Bugu da ƙari, dabaru kamar seismology sun haifar da ƙarin fahimtar yiwuwar kasancewar carbon a cikin ainihin Duniya.
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Carbon yafi shiga cikin mantle a cikin nau'in carbonate-mai wadataccen sediments a kan tectonic faranti na teku, wanda ke jan carbon cikin mantle bayan da ya sha wahala. Ba a san abubuwa da yawa game da yaduwar carbon a cikin mantle ba, musamman a cikin zurfin Duniya, amma bincike da yawa sun yi ƙoƙari su kara fahimtarmu game da motsi da siffofin kashi a cikin yankin. Misali, binciken da akayi a shekara ta 2011 ya nuna cewa zagaye na carbon yakai har zuwa ƙananan mantle. Binciken yayi nazarin lu'u-lu'u masu zurfi a wani shafin a Juina, Brazil, yana ƙayyade cewa yawancin abubuwan da ke cikin wasu lu'u'u-ulu'u sun dace da sakamakon da ake tsammani na narkewar basalt da crystallisation a ƙarƙashin ƙananan yanayin zafi da matsin lamba. Don haka, binciken binciken ya nuna cewa ɓangarorin basaltic oceanic lithosphere suna aiki a matsayin ƙa'idar hanyar sufuri don carbon zuwa zurfin ciki na Duniya. Wadannan carbonates da aka rage zasu iya hulɗa tare da ƙananan silicates, a ƙarshe suna samar da lu'u-lu'u masu zurfi kamar wanda aka samu.[78]
Koyaya, carbonates da ke saukowa zuwa ƙananan mantle suna haɗuwa da wasu abubuwan da suka faru banda samar da lu'u-lu'u. A cikin shekara ta 2011, an sanya carbonates a cikin yanayin da yayi kama da na zurfin kilomita 1800 a cikin Duniya, da kyau a cikin ƙananan mantle. Yin haka ya haifar da tsarin Magnesite, siderite, da nau'ikan nau'ikan graphite.[79] Sauran gwaje-gwaje - kazalika da abubuwan lura na petrologic - suna tallafawa wannan da'awar, suna nuna cewa magnesite shine ainihin matakin carbonate mafi tsayayya a mafi yawan ɓangaren mantle. Wannan galibi sakamakon yawan zafin jiki ne.[80] Sakamakon haka, masana kimiyya sun kammala cewa carbonates suna fuskantar raguwa yayin da suke sauka cikin mantle kafin a daidaita su a zurfi ta hanyar yanayin oxygen fugacity. Magnesium, baƙin ƙarfe, da sauran mahadi na ƙarfe suna aiki azaman buffers a duk lokacin da aka aiwatar.[81] Kasancewar ragewa, siffofin carbon kamar graphite zai nuna cewa mahaɗan carbon suna raguwa yayin da suke sauka cikin mantle.
Binciken Kasuwancin Majalisar Dinkin Duniya na 2009-2010 ya ba da rahoton cewa kamfanonin da suka samar ko suka yi ciniki a cikin samfuran gandun daji masu inganci galibi suna da fa'idar kasuwa a lokacin koma bayan tattalin arziki na 2008-2009 saboda, a cikin kasuwar masu siye, masu siye na iya zama mafi zaɓaɓɓu wajen zaɓar hanyoyin samar da su. Rahoton ya ambaci direbobi huɗu da ake buƙata don takaddun shaida: yana canza kwanciyar hankali na mahaɗan carbonate a zurfi daban-daban a cikin Duniya. Don kwatanta, ƙididdigar dakin gwaje-gwaje da ƙididdigaren ka'idar aiki mai yawa sun nuna cewa carbonates da aka daidaita da tetrahedrally sun fi kwanciyar hankali a zurfin da ke kusa da iyakar core-mantle.[82][83] Wani binciken da akayi a shekarar 2 ya nuna cewa matsin lamba na ƙananan mantle yana haifar da haɗin carbon zuwa sauyawa daga sp2 zuwa sp3 Hybridized orbitals, wanda ke haifar da haɗin haɗin carbon tetrahedrally zuwa oxygen.[84] Ƙungiyoyin CO3 trigonal ba zasu iya samar da cibiyoyin sadarwa masu polymerisable ba, yayin da CO4 na tetrahedral zai iya, yana nuna karuwar lambar daidaitawa carbon, sabili da haka canje-canje masu yawa a cikin kaddarorin carbonate a cikin ƙananan mantle. A matsayin misali, binciken farko na ka'idoji ya nuna cewa matsin lamba yana haifar da ƙarancin narkewar carbonate don ƙaruwa; ƙarancin motsi na narkewa sakamakon ƙaruwar ƙarancin yana haifar da manyan ajiyar carbon a cikin mantle.[85]
Dangane da haka, carbon na iya kasancewa a cikin ƙananan mantle na dogon lokaci, amma babban taro na carbon akai-akai yana samun hanyar komawa zuwa lithosphere. Wannan tsari, wanda ake kira carbon outgassing, shine sakamakon carbonated mantle dake fuskantar narkewar decompression, da kuma mantle plumes dauke da carbon mahadi zuwa ga ɓawon burodi.[86] Carbon yana narkewa a lokacin da yake hawa zuwa wuraren dake cike da wuta, inda aka sake shi azaman CO2. Wannan yana faruwa ne don atom din carbon yadace da yanayin oxidation na basalts dake fashewa a irin waɗannan yankuna.[87]
Kodayake kasancewar carbon a cikin ainihin duniya yana da iyaka sosai, binciken da akayi kwanan nan ya nuna cewa za'a iya adana manyan kayayyaki na carbon a wannan yankin. [bayyanawa da ake buƙata] Raƙuman Shear (S) dake motsawa ta cikin tsakiya na ciki suna tafiya a kusan kashi hamsin cikin dari na saurin da ake tsammani ga mafi yawan ƙarfe masu wadata. Saboda anyi imanin cewa abun dake cikin core shine gami na ƙarfe mai haske da ƙaramin nickel, wannan anomaly na girgizar ƙasa yana nuna kasancewar abubuwa masu haske, gami da carbon, a cikin core. A zahiri, binciken da ke amfani da ƙwayoyin lu'u-lu'u don sake maimaita yanayin da ke cikin ainihin Duniya ya nuna cewa 7" href="./Cementite" id="mwAs0" rel="mw:WikiLink" title="Cementite">Karfe carbide (Fe7C3) ya dace da saurin raƙuman ruwa na ciki dayawa. Sabili da haka, samfurin ƙarfe na ƙarfe na iya zama shaida cewa ainihin yana riƙe da kashi 67% na carbon na Duniya.[88] Bugu da ƙari, wani binciken ya gano cewa a cikin matsin lamba da yanayin zafin jiki na ainihin duniya, carbon ya narke cikin baƙin ƙarfe kuma ya kafa wani lokaci mai ɗorewa tare da wannan abun dake ciki na Fe7 - duk da cewa yana da tsari daban daga wanda aka ambata a baya.[3] A taƙaice, kodayake ba'a san adadin carbon da za'a iya adanawa a cikin asalin Duniya ba, binciken da akayi kwanan nan ya nuna cewa kasancewar ƙarfe na ƙarfe na iya bayyana wasu abubuwan lura na geophysical.
Tun lokacin juyin juya halin masana'antu, kuma musamman tun ƙarshen WWII, aikin ɗan adam ya dame sake zagayowar carbon na duniya ta hanyar sake rarraba yawan carbon daga geosphere.[1] Mutane sun kuma ci gaba da canza ayyukan sassan halitta na yanayin halittu na duniya tare da canje-canje ga ciyayi da sauran amfani da ƙasa.[5] An tsara mahaɗan carbon da aka yi da mutum (na roba) kuma anyi su dayawa wanda zai cigaba da shekaru dayawa zuwa dubban shekaru a cikin iska, ruwa, da turɓaya a matsayin gurɓataccen.[89] Canjin yanayi yana fadadawa kuma yana tilasta ƙarin canje-canje na ɗan adam kai tsaye zuwa sake zagayowar carbon a matsayin sakamakon ra'ayoyi masu kyau da marasa kyau.[21]
Halin da ke faruwa a yanzu a cikin canjin yanayi yana haifar da yanayin zafi na teku da acidity, don haka yana canza yanayin halittu na ruwa.[91] Har ila yau, ruwan sama mai zafi da gurɓataccen ruwa daga aikin gona da masana'antu suna canza sinadarin sinadarai na teku. Irin waɗannan canje-canje na iya samun tasiri mai ban mamaki a kan yanayin halittu masu mahimmanci kamar coral reefs, [92] don haka iyakance ikon teku na sha carbon daga yanayi a kan sikelin yanki da rage bambancin halittu na teku a duniya.
Canjin carbon tsakanin yanayi da sauran abubuwan dake cikin tsarin duniya, wanda akafi sani da sake zagayowar carbon, a halin yanzu ya zama muhimmiyar mummunan ra'ayi (dampening) game da tasirin hayakin carbon na mutum akan canjin yanayi. Carbon nutsewa a cikin ƙasa da teku kowannensu a halin yanzu yana ɗaukar kusan kashi ɗaya cikin huɗu na hayakin carbon na mutum a kowace shekara.[93][90]
Ana sa ran waɗannan abubuwan zasu raunana a nan gaba, suna kara tasirin hayakin carbon na mutum akan canjin yanayi. Matsayin da zasu raunana, duk da haka, ba shi da tabbas, tare da samfuran tsarin Duniya da ke hasashen kewayon ƙasa da teku carbon ko da a ƙarƙashin maida hankali ga yanayi ko yanayin fitarwa.[94][90] Yankin Arctic methane wanda ya haifar da dumama na duniya ya shafi sake zagayowar carbon kuma ya ba da gudummawa ga cigaba da dumama.
Mafi girma kuma daya daga cikin tasirin mutum mafi sauri a kan sake zagayowar carbon da biosphere shine cirewa da ƙone burbushin burbushin halittu, wanda ke canja wurin carbon kai tsaye daga geosphere zuwa cikin yanayi. Hakanan ana samar da carbon dioxide kuma ana fitar dashi yayin ƙonewa dutse don samar da clinker. Clinker shine mai gabatarwa da masana'antu na siminti.
EatAs of 2020[update], an cire kimanin 450 gigatons na burbushin carbon gabaɗaya; adadin dake kusa da carbon dake ƙunshe a duk abubuwan dake rayuwa a duniya.[95] Yawan fitar da hayaki na duniya kai tsaye a cikin yanayi ya wuce abin da shuke-shuke da tekuna suka ɗauka.[96][97] Ana sa ran waɗannan sinks kuma an lura dasu don cire kusan rabin ƙarawar carbon a cikin kimanin ƙarni guda.[95] Duk da haka, sinks kamar teku suna da abubuwan dake tattare dasu, kuma wani bangare mai yawa (20-35%, bisa ga samfuran da aka haɗa) na carbon da aka kara ana sa ran zai kasance a cikin yanayi na ƙarni zuwa dubban shekaru. [98][99]
Halocarbons sune ƙananan mahadi waɗanda aka haɓaka don amfani daban-daban a duk masana'antu; misali a matsayin masu narkewa da masu sanyaya. Duk da haka, tara ƙananan ƙananan maida hankali (kashi na tiriliyan) na chlorofluorocarbon, hydrofluorocarbon. da iskar gas a cikin yanayi suna da alhakin kusan 10% na jimlar tilasta radiative kai tsaye daga duk iskar gas mai ɗorewa (shekara ta 2019); wanda ya haɗa da tilasta daga mafi girma na carbon dioxide da methane.[100] Chlorofluorocarbons kuma suna haifar da raguwar ozone na stratospheric. Ƙoƙarin ƙasashen duniya suna ci gaba a ƙarƙashin Yarjejeniyar Montreal da Yarjejeniyar Kyoto don sarrafa saurin cigaba a cikin masana'antu da amfani da waɗannan iskar gas masu ƙarfi. Ga wasu aikace-aikace an haɓaka wasu hanyoyin da basu da kyau kamar hydrofluoroolefins kuma ana gabatar da su a hankali.
Tun lokacin da aka kirkiro aikin gona, mutane sun kai tsaye kuma a hankali sun rinjayi sake zagayowar carbon a tsawon lokaci ta hanyar canza cakuda ciyayi a cikin yanayin halittu na duniya. A cikin ƙarni da yawa da suka gabata, Amfani da ƙasa kai tsaye da kai tsaye da kuma sauyawar rufe ƙasa (LUCC) ya haifar da asarar bambancin halittu, wanda ke rage ƙarfin yanayin halittu ga matsalolin muhalli kuma yana rage ikon su na cire carbon daga yanayi. Fiye da haka, sau dayawa yana haifar da sakin carbon daga yanayin halittu na ƙasa zuwa cikin yanayi.
Kashe gandun daji don dalilai na noma yana cire gandun daji, wanda ke riƙe da adadi mai yawa na carbon, kuma ya maye gurbin su, gabaɗaya tare da aikin gona ko birane. Dukkanin waɗannan nau'ikan murfin ƙasa suna adana ƙananan carbon don sakamakon canjin shine ƙarin carbon ya kasance a cikin yanayi. Koyaya, tasirin dake kan yanayi da sake zagayowar carbon gabaɗaya ana iya juyawa da gangan da / ko kuma ta halitta tare da sake dasa bishiyoyi.
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