Ngokuqinisekileyo wakhe weva iqabaka. Ngumaleko womhlaba ongaphantsi okwingqimba yomhlaba kwaye omiswe ngokusisigxina ngenxa yendalo kunye nemozulu apho ifunyenwe khona. Igama lalo livela kule ndawo ikhenkcisayo ngokusisigxina. Nangona lomaleko womhlaba ongaphantsi ungumkhenkce ngokusisigxina, awugutyungelwanga ngumkhenkce okanye ikhephu ngokuqhubekayo. Ifumaneka kwiindawo ezinemozulu ebanda kakhulu kunye nepariglacial.
Kweli nqaku siza kukuxelela ngazo zonke iimpawu, ukubunjwa kunye neziphumo ezinokunyibilika kwi-permafrost.
Iimpawu eziphambili
I-permafrost ineminyaka yobudala be-geological ukongeza kwi-15 lamawaka eminyaka. Nangona kunjalo, ekubeni utshintsho lwemozulu lusanda kubushushu behlabathi, olu hlobo lomhlaba lusengozini yokunyibilika. Ukunyibilikiswa okungagungqiyo kwale permafrost kunokubangela iziphumo ezahlukeneyo esiza kubona kamva kweli nqaku. Yenye yeengozi ezinkulu esakha sahlangabezana nazo malunga notshintsho lwemozulu kule minyaka ilishumi.
I-permafrost yahlulwe yangamacandelo amabini. Kwisandle esinye, sine-pergelisol. Olu lolona luhlu lunzulu lwalo mhlaba kwaye lumiswe ngumkhenkce ngokupheleleyo. Kwelinye icala, sine-molisol. UMolisole ngowona mgangatho ungaphezulu kwaye unganyibilika ngokulula ngokutshintsha kwamaqondo obushushu okanye iimeko ezikhoyo ngoku.
Akufuneki sididanise iqabaka nomkhenkce. Akuthethi ukuba ngumhlaba ogqunywe ngumkhenkce, kodwa ngumhlaba ongumkhenkce. Lo mhlaba ungasokola kakhulu elityeni nasentlabathini okanye utyebe kakhulu ngezinto eziphilayo. Oko kukuthi, lo mhlaba unokuba nesixa esikhulu samanzi afriziwe okanye unokuqulatha phantse ukuba akukho manzi.
Ifumaneka kwimimandla ephantsi komhlaba phantse kuyo yonke indawo kwiindawo ezibandayo. Ngokukodwa Sifumana eSiberia, eNorway, eTibet, eCanada, eAlaska nakwiziqithi ezikumazantsi oLwandlekazi lweAtlantic. Oku kuhlala kuphela phakathi kwama-20 nama-24% omhlaba kwaye kungaphantsi koko kuhlala iintlango. Olunye lweempawu eziphambili zalo mhlaba kukuba ubomi bunokuphuhla kuwo. Kule meko, siyabona ukuba itundra ikhula kumhlaba onomkhenkce onganyibilikiyo.
Kutheni le nto i-permafrost thawing iyingozi?
Kuya kufuneka uyazi ukuba ngamawaka kunye namawaka eminyaka I-permafrost inoxanduva lokuqokelela oovimba abakhulu bekhabhoni. Njengoko sisazi, xa umntu ophilayo esifa, umzimba wakhe ubola ube yinto yendalo. Lo mhlaba ufunxa izinto eziphilayo ezinesixa esikhulu sekhabhon kuwo. Oku kuthetha ukuba i-permafrost iye yakwazi ukuqokelela i-1.85 trillion yeetriliyoni zecarbon ye-organic.
Xa sibona ukuba i-permafrost iqala ukunyibilika kukho ingxaki enkulu ngenxa yoko. Kwaye le nkqubo yokunyibilika komkhenkce kuthetha ukuba yonke i-organic khabhoni egcinwe ngumhlaba iphuma ikwimo yemethane kunye nekharbon diokside kwiatmosfera. Oku kunyibilika kubangela ukuba iigesi zegreenhouse zinyukele emoyeni. Siyakhumbula ukuba icarbon dioxide kunye nemethane ziigesi ezimbini zegreenhouse ezikwaziyo ukugcina ubushushu emoyeni kwaye zibangele ukwanda kubushushu behlabathi.
Kukho isifundo esiluncedo kakhulu esinoxanduva lokurekhoda ukwanda kwamaqondo obushushu njengomsebenzi wotshintsho ekugxileni kwezi ntlobo zimbini zeegesi zegreenhouse emoyeni. Unobangela ophambili wolu phononongo ngu Hlalutya iziphumo zokunyibilika komkhenkce onganyibilikiyo. Ukwazi olu tshintsho kumaqondo obushushu, abaphandi kufuneka bagrade ngaphakathi ukuze bakhuphe iisampulu ezimbalwa ukuze bakwazi ukurekhoda inani lekhabhoni ekhoyo kubo.
Kuxhomekeka kubungakanani bezi gesi, umahluko weklimati unokurekhodwa. Ngokwanda okukhulu kwamaqondo obushushu, le mihlaba ikhenkceze amawaka eminyaka iqale ukunyibilika ngesantya esinganqandekiyo. Le yikhonkco lokuzondla. Oko kukuthi, ukunyibilika komkhenkce onganyibilikiyo kubangela ukwanda kwamaqondo obushushu athi wona, iya kubangela ukuba i-permafrost ngakumbi inyibilike. Emva koko, fikelela kwinqanaba apho iqondo lobushushu lehlabathi liphela liza kunyuka ngokumangalisayo.
Iziphumo zokunyibilika kwe-permafrost
Njengoko sisazi, utshintsho lwemozulu lulawulwa kukunyuka kwamaqondo obushushu aphakathi komhlaba. La maqondo obushushu aphakathi anokubangela utshintsho kwiipateni zemozulu kwaye abangele iimeko ezingaqhelekanga. Iziganeko ezinobungozi ezinje ngembalela ende kunye neyaqatha, ukwanda kwamaxesha ezikhukhula, iinkanyamba, iinkanyamba kunye nezinye izinto ezingaqhelekanga.
Kuluntu lwenzululwazi kwafumaniseka ukuba ukwanda kubushushu obumgangatho wehlabathi obungu-2 degrees celcius kunokubangela ilahleko ye-40% yomhlaba wonke ekuhlala kuwo i-permafrost. Kuba ukususwa kwalo mgangatho kubangela ukulahleka kolwakhiwo, kuye kube kubi kakhulu kuba umgangatho uxhasa yonke into engaphezulu kunye nobomi. Ukulahleka kwalo mhlaba kuthetha ukuphulukana nayo yonke into engaphezulu kwawo. Oku kuchaphazela ulwakhiwo olwenziwe ngabantu kunye namahlathi ngokwawo kunye nayo yonke indawo enxulumene noko.
I-permafrost efumaneka kumazantsi e-Alaska kunye nase-Siberia esezantsi sele inyibilikile. Oku kwenza ukuba eli candelo liphela lisengozini. Kukho iinxalenye zecrafafrost ezipholileyo kwaye ezizinzileyo kwiindawo eziphezulu zeAlaska naseSiberia. Ezi ndawo zibonakala zikhuselwe ngcono ngcono kutshintsho olukhulu lwemozulu. Utshintsho olukhulu lwalulindelekile kwiminyaka engama-200 ezayo, kodwa njengoko amaqondo obushushu enyuka bayabonana ngaphambi kwexesha.
Ukunyuka kwamaqondo obushushu asuka e-Arctic emoyeni kubangela ukuba i-permafrost inyibilike ngokukhawuleza kwaye zonke izinto eziphilayo zibola kwaye zikhuphe yonke ikhabhoni yayo iye kwiatmosferi ngohlobo lweegesi zegreenhouse.
Ndiyathemba ukuba olu lwazi lunokufunda ngakumbi malunga ne-permafrost kunye nesiphumo sokunyibilika kwayo.