Komawar kankara tun daga 1850

Komawar kankara tun daga 1850

Iri	aukuwa
Sanadi	Canjin yanayi
Hanyar isar da saƙo

Komawar kankara tun daga 1850 sakamako ne mai kyau na Canjin yanayi. Komawar kankara na tsaunuka yana ba da shaida ga hauhawar yanayin zafi na duniya tun daga ƙarshen karni na 19. Misalan sun haɗa da tsaunuka masu kankara a yammacin Arewacin Amurka, Asiya, Alps a tsakiyar Turai, da yankuna masu zafi da masu zafi na Kudancin Amurka da Afirka. Tunda sauye-sauyen yanayi na dogon lokaci suna shafar yawan kankara, misali hazo, matsakaicin zafin jiki, da Rufin girgije, sauye-shiryen yawan kankara suna daya daga cikin alamun sauyin yanayi. Komawar kankara kuma babban dalili ne na hauhawar matakin teku. Ba tare da kankara na kankara ba, jimlar asarar kankara ta duniya a cikin shekaru 26 daga 1993 zuwa 2018 mai yiwuwa 5500 gigatons, ko 210 gigatons a kowace shekara. : 1275 

A Duniya, 99% na kankara na glacial yana ƙunshe a cikin ɗigon kankara (wanda kuma aka sani da "ƙanƙarar glaciers") a cikin yankunan polar. Glaciers kuma suna wanzu a cikin jeri na tsaunuka a kowace nahiya ban da babban yankin Ostiraliya, gami da manyan tsibiran teku na Oceania kamar New Zealand. Jikunan glacial mafi girma fiye da murabba'in kilomita 50,000 (19,000 sq mi) ana kiran su da zanen kankara.[1] Suna da zurfin kilomita da yawa kuma sun ɓoye yanayin yanayin ƙasa.

Deglaciation yana faruwa ta halitta a ƙarshen zamanin kankara. Amma raguwar kankara na yanzu yana hanzarta ta hanyar dumama ta duniya saboda fitar da iskar gas mai guba da mutum ya haifar. Ayyukan ɗan adam tun farkon zamanin masana'antu sun ƙara yawan carbon dioxide da sauran iskar gas mai zafi a cikin iska, wanda ke haifar da dumamar duniya a yanzu. Tasirin ɗan adam shine babban abin da ke haifar da canje-canje ga cryosphere, wanda glaciers wani ɓangare ne.

Ma'aunin ma'aunin kankara shine mabuɗin ƙayyade lafiyar kankara. Idan adadin ruwan sama mai daskarewa a cikin Yankin tarawa ya wuce yawan kankara mai kankara yankin da ya ɓace saboda narkewa, kankara zai ci gaba. Idan tarin ya fi ƙasa da raguwa, kankara zai koma baya. Gilashiers a cikin koma baya za su sami ma'auni mara kyau. A ƙarshe za su ɓace idan ba su kai ga daidaituwa tsakanin tarawa da ablation ba.

Tsakanin tsaunuka na tsakiya suna nuna wasu daga cikin mafi girman asarar glacial. Misalan irin waɗannan tsaunuka sune Himalayas a Asiya, Dutsen Rocky da Cascade Range a Arewacin Amurka, Alps a Turai, Kudancin Alps a New Zealand, kudancin Andes a Kudancin Amurka, da kuma tarurruka masu zafi kamar Dutsen Kilimanjaro a Afirka.

 

Scale a matakin duniya

Daga 1970 zuwa 2004, tsaunuka masu kankara sun ragu (zaki da ja) a wasu yankuna kuma sun yi kauri (blue) a wasu.

Rugujewar yanayi tana ba da gudummawa ga runoff; daidaitattun shekara-shekara (canjin cibiyar gilashi) yana ba da gudana ga hauhawar matakin teku.

Ba tare da kankara na kankara ba, jimlar asarar kankara ta duniya a cikin shekaru 26 daga 1993 zuwa 2018 mai yiwuwa 5500 gigatons, ko 210 gigatons a kowace shekara. : 1275 

Jerin lokaci

Little Ice Age wani lokaci ne daga kimanin 1550 zuwa 1850 lokacin da wasu yankuna suka sami yanayin sanyi idan aka kwatanta da lokacin da ya gabata da kuma bayan. Daga baya, har zuwa kimanin 1940, kankara a duniya sun koma baya yayin da yanayin ya yi zafi sosai. Gudun kankara ya ragu har ma ya juya na ɗan lokaci, a lokuta da yawa, tsakanin 1950 da 1980 yayin da yanayin duniya ya ɗan sanyaya.

Tun daga shekara ta 1980, Canjin yanayi ya haifar da koma baya na kankara ya zama mai saurin gaske kuma yana ko'ina, har ya sa wasu kankara sun ɓace gaba ɗaya, kuma kasancewar yawancin sauran kankara suna barazana.

Dalilan da suka haifar

Ma'auni na taro, ko bambanci tsakanin tarawa da ablation (melting da sublimation), na kankara yana da mahimmanci ga rayuwarsa. Canjin yanayi na iya haifar da bambance-bambance a cikin zafin jiki da dusar ƙanƙara, wanda ke haifar da canje-canje a cikin ma'auni. Gilashin da ke da daidaitattun daidaito mara kyau ya rasa daidaituwa kuma ya koma baya. Daidaitaccen daidaituwa mai kyau kuma ba shi da daidaituwa kuma zai ci gaba don sake kafa daidaituwa. A halin yanzu, kusan dukkanin kankara suna da ma'auni mara kyau kuma suna janyewa

Komawar kankara yana haifar da asarar yankin da ke ƙasa da kankara. Tunda tsaunuka masu tsawo sun fi sanyi, ɓacewar ɓangaren mafi ƙasƙanci yana rage raguwa gaba ɗaya, don haka ƙara ma'auni na taro kuma yana iya sake kafa daidaituwa. Idan ma'auni na wani bangare mai mahimmanci na yankin tarawa na kankara ba shi da kyau, yana cikin rashin daidaituwa tare da yanayi kuma zai narke ba tare da yanayin sanyi da / ko karuwar ruwan sama mai daskarewa ba.

Misali, Easton Glacier a jihar Washington, Amurka mai yiwuwa zai ragu zuwa rabin girmansa amma a raguwar raguwa da daidaitawa a wannan girman duk da zafin jiki mai zafi a cikin 'yan shekarun da suka gabata. Koyaya, Grinnell Glacier a Montana, Amurka za ta ragu da ƙaruwa har sai ya ɓace. Bambanci shi ne cewa ɓangaren sama na Easton Glacier ya kasance lafiya kuma an rufe shi da dusar ƙanƙara, yayin da ɓangaren sama da Grinnell Glacier ba shi da komai, yana narkewa kuma ya ragu. Ƙananan kankara tare da ƙananan tsawo suna iya fadawa cikin rashin daidaituwa tare da yanayi.