Impela wake wezwa permafrost. Ungqimba lwenhlabathi engaphansi okuwuqweqwe lomhlaba nolumiswe ngokuphelele unomphela ngenxa yesimo salo nesimo sezulu lapho litholakala khona. Igama layo livela kulokhu kubanda okungapheli. Yize lolu ungqimba lomhlabathi ongaphansi luba yiqhwa unomphela, alumboziwe ngeqhwa noma iqhwa ngokuqhubekayo. Kutholakala ezindaweni ezinesimo sezulu esibanda kakhulu futhi esiseduze.
Kulesi sihloko sizokutshela ngazo zonke izici, ukwakheka nemiphumela engaba khona yokuncibilika kwe-permafrost.
Izici eziyinhloko
I-permafrost inesikhathi semvelo ngokungeziwe eminyakeni eyizinkulungwane eziyi-15. Kodwa-ke, njengoba ukuguquka kwesimo sezulu kwanda amazinga okushisa aphakathi komhlaba, lolu hlobo lomhlabathi lusengozini yokuncibilika. Ukuncibilika okuqhubekayo kwaleli qhwa kungadala imiphumela ehlukahlukene esizoyibona kamuva kule ndatshana. Kungenye yezingozi ezinkulu esike sahlangabezana nazo maqondana nokuguquka kwesimo sezulu kule minyaka eyishumi.
I-permafrost ihlukaniswe izingxenye ezimbili. Ngakolunye uhlangothi, sine-pergelisol. Lolu ungqimba olujule kakhulu lwale nhlabathi futhi lumbozwe ngokuphelele. Ngokwesinye isandla, sine-molisol. I-Molisole ungqimba olukha phezulu kakhulu futhi lungancibilika kalula ngokushintsha kwamazinga okushisa noma izimo zamanje zemvelo.
Akufanele sididanise iqhwa eliqhwaqhwa neqhwa. Akusho ukuthi ngumhlabathi ovalwe yiqhwa, kepha ukuthi uyindawo efriziwe. Le nhlabathi ingaba mpofu kakhulu edwaleni nasesihlabathini noma icebe kakhulu ezintweni eziphilayo. Okusho ukuthi, le nhlabathi ingaba nenani elikhulu lamanzi afriziwe noma ingaqukatha cishe akukho ketshezi.
Kutholakala ezindaweni ezingaphansi komhlaba ezicishe zibe yiplanethi yonke ezindaweni ezibandayo. Ngokuqondile Siyithola eSiberia, eNorway, eTibet, eCanada, e-Alaska naseziqhingini eziseSouth Atlantic Ocean. Lokhu kuphela phakathi kuka-20 no-24% womhlaba futhi kuncane kunalokho okuhlala ezingwadule. Esinye sezici eziyinhloko zalo mhlabathi ukuthi impilo ingakhula kuwo. Kulokhu, siyabona ukuthi i-tundra ikhula enhlabathini ye-permafrost.
Kungani ukuncibilika kweqhwa eliyingozi kuyingozi?
Kufanele ukwazi lokho ngezinkulungwane zeminyaka i-permafrost ibhekele ukuqoqa izinqolobane ezinkulu zekhabhoni ephilayo. Njengoba sazi, lapho umuntu ophilayo efa, umzimba wakhe uyawohloka ube yinto ephilayo. Le nhlabathi imunca izinto eziphilayo ezinenani elikhulu lekhabhoni kuyo. Lokhu kusho ukuthi i-permafrost ikwazile ukuqoqa cishe amathani ayi-1.85 trillion wekhabhoni ephilayo.
Lapho sibona ukuthi i-permafrost iqala ukuncibilika kunenkinga enkulu njengomphumela. Futhi le nqubo yokuncibilika kweqhwa isho ukuthi yonke i-organic carbon egcinwe ngumhlabathi ikhishwa ngesimo se-methane ne-carbon dioxide emkhathini. Lokhu kuncibilika kubangela ukuthi amagesi abamba ukushisa akhuphukele emkhathini. Siyakhumbula ukuthi i-carbon dioxide ne-methane kungamagesi amabili abamba ukushisa anekhono lokugcina ukushisa emkhathini futhi kubangele ukwanda kwamazinga okushisa emhlabeni jikelele.
Kunesifundo esiwusizo kakhulu esibhekele ukuqopha ukwanda kwamazinga okushisa njengomsebenzi wokushintsha kokugxila kulezi zinhlobo ezimbili zamagesi abamba ukushisa emkhathini. Imbangela enkulu yalolu cwaningo hlaziya umphumela osheshayo wokuncibilika kweqhwa leqhwa. Ukwazi lolu shintsho emazingeni okushisa, abacwaningi kumele babhoboze ingaphakathi ukuze bakhiphe amasampula ambalwa ukuze bakwazi ukuqopha inani lekhabhoni ephilayo ekhona kubo.
Ngokuya ngenani lala magesi, ukuhluka kwesimo sezulu kungarekhodwa. Ngokwanda okukhulu kwamazinga okushisa, le nhlabathi ebifriziwe izinkulungwane zeminyaka isiqale ukuncibilika ngesilinganiso esinganqandeki. Leli iketanga lokuzondla. Okusho ukuthi, ukuncibilika kweqhwa okubangela iqhwa kubangela ukwanda kwamazinga okushisa, kuzokwenza ukuthi i-permafrost eyengeziwe incibilike. Ngemuva kwalokho, finyelela ezingeni lapho amazinga okushisa aphakathi komhlaba azokwenyuka kakhulu.
Imiphumela yokuncibilika kweqhwa
Njengoba sazi, ukuguquka kwesimo sezulu kubuswa ukwanda kwamazinga okushisa aphakathi komhlaba. La mazinga okushisa aphakathi nendawo angadala ushintsho emaphethini wezulu futhi adale nezimo ezingavamile. Izimo eziyingozi ezifana nesomiso esihlala isikhathi eside futhi esibi kakhulu, ukwanda kokuqubuka kwezikhukhula, izivunguvungu, izivunguvungu nezinye izehlakalo ezingavamile.
Emphakathini wezesayensi kwatholakala ukuthi ukwanda kokushisa okuphakathi komhlaba okuyi-2 degrees Celsius kungadala ukulahleka okungu-40% wobuso bonke obuhlala kwi-permafrost. Njengoba ukuncibilika kwaleli phansi kudala ukulahleka kwesakhiwo, kuba kubi kakhulu njengoba iphansi lisekela konke okungaphezulu nokokuphila. Ukulahleka kwalo mhlabathi kusho ukulahlekelwa yikho konke okungaphezulu kwawo. Lokhu kuthinta nezakhiwo ezenziwe ngabantu kanye namahlathi uqobo kanye nayo yonke imvelo ehlobene nayo.
I-permafrost etholakala eningizimu ye-Alaska naseningizimu yeSiberia seyivele incibilika. Lokhu kwenza yonke le ngxenye ibe sengozini kakhulu. Kunezingxenye zeqhwa elipholile futhi elizinzile ezindaweni eziphakeme zase-Alaska naseSiberia. Lezi zindawo zibukeka zivikeleke kangcono ngandlela thile ekushintsheni kwesimo sezulu esibi kakhulu. Izinguquko ezinqala bezilindelwe eminyakeni engama-200 ezayo, kepha njengoba izinga lokushisa likhuphuka bayabonana ngaphambi kwesikhathi.
Ukukhuphuka kwamazinga okushisa asuka emoyeni wase-Arctic kubangela ukuthi i-permafrost inyibilike ngokushesha futhi konke okokusebenza komzimba kubola futhi kudedele yonke ikhabhoni yayo emkhathini ngendlela yamagesi abamba ukushisa.
Ngiyethemba lolu lwazi lungafunda kabanzi mayelana ne-permafrost nomphumela wokuncibilika kwayo.