Esikhathini esingengakanani esidlule i-Arctic Ocean yayimbozwe yonke yiqhwa unyaka wonke, kufaka phakathi ehlobo. Ebusika, amashidi e-ice ayemakhulu kakhulu futhi asakazeka ezindaweni eziphansi, ekugcineni ahlanganisa uLwandle iGreenland nolwandle iBering. Ehlobo, ngenxa yokwanda kwamazinga okushisa, amashidi eqhwa ahlehla nokho, unqenqema olufriziwe lwafinyelela eduze kakhulu nasogwini.
Lesi simo siyashintsha ngokuhamba kweminyaka. Ngaso sonke isikhathi lapho izigaxa zeqhwa zincane futhi kunendawo encane efriziwe. Yini ebingenzeka uma i-Arctic ibingenalo iqhwa ngokuphelele?
Ukubuyisela ama-ice sheet
Isimo ebesizibona sikuso ngaphambili kanye nalesi esinaso manje sihluke ngokuphelele. Ubuso obabuya emuva ngaleso sikhathi yayinamakhilomitha-skwele angaba yizigidi eziyi-8 ngenyanga kaSepthemba, namuhla kuphela ngaleyo nyanga cishe amakhilomitha ayizigidi ezingama-3-4. NgoSepthemba yilapho amashidi eqhwa ehlehla kakhulu. Lokhu kubonisa ukuthi ukujiya kwamaqhwa kuncishiswe ngesigamu. Iqhwa lasehlobo liyingxenye yesine kuphela yevolumu elaliyiyo ngawo-1970. Ukuhlaziya lezi zibalo kubalulekile ukuze uqonde imiphumela yokuncibilika okuphelele kweqhwa lase-Arctic.
Ngenxa yokufudumala kwembulunga yonke, i-Arctic ithuthukisa ukuncibilika kwayo kabili noma kathathu ijubane lomhlaba wonke. Lokhu kungenxa yochungechunge lokuhamba lokushisa oluvela enkabazwe. Lokhu kushesha kokufudumala kwe-Arctic kuzoholela ehlobo elingenalo iqhwa esikhathini esifushane.
Unyaka nonyaka lapho kubhalwa amazinga okushisa waminyaka yonke, siyabona ukuthi kuyashisa kunakuqala, ngo-2016 kube okushisa kakhulu selokhu amazinga okushisa aqala ukukalwa lapho ngawo-1880. Ngaphambilini, ngenkathi kubhekwa iqhwa lase-Arctic, kwakukhulunywa ngakho iqhwa leminyaka eminingi. Lokhu kusho ukuthi iqhwa elalibonwa lalakheke eminyakeni eminingana edlule nokuthi lahlala ngemuva kokuhamba kwezinkathi. Ngenxa yeminyaka eyasungulwa ngayo, babekwazi ukufinyelela ezindaweni eziphakeme kakhulu, isimo sendawo esimangelengele nemikhawulo emikhulu eyayivimbela ukudlula kwabahloli bamazwe nemikhumbi.
Namuhla cishe lonke iqhwa elibukwayo lingonyaka wokuqala. Okusho ukuthi, kwakhiwe phakathi nenkathi yamanje. Imvamisa zifinyelela kuphela ingamamitha ayi-1,5 ukujiya futhi ayinayo ngaphezu kwemikhawulo embalwa. Iqhwa elenzeka ebusika obubodwa (futhi kucatshangelwa ukuthi isikhathi ngasinye lapho amazinga okushisa ephakeme) lingancibilika phakathi nehlobo elilodwa. Lokhu kubangela ukufa kweqhwa ehlobo.
Imiphumela yokunyamalala kweqhwa
Kwehlisiwe i-albedo
Selokhu saqala ukukhuluma ngokufudumala komhlaba kanye nokushintsha kwesimo sezulu, besilokhu sikhuluma ngokuncibilika kweqhwa lase-Arctic nase-Antarctic. Yebo, imiphumela yokunyamalala kwala maqhwa amakhulu ziyamangaza kakhulu iplanethi. I-Albedo iphesenti lemisebe yelanga ekhonjiswa noma ebuyela emkhathini. Yebo, omunye wemiphumela yokunyamalala kwama-ice sheet kungaba ukwehliswa kwe-albedo kusuka 0,6% kuya ku-0,1%. Lokhu kuholela ekugcinweni okukhulu kokushisa phezu komhlaba futhi, ngakho-ke, ukwanda kwamazinga okushisa omhlaba. Ungathola kabanzi mayelana nalesi simo ku- ukuncibilika kwezilwandle.
Inkinga nge-albedo ukuthi iqhwa lasehlobo lihlehla ngesikhathi lapho kutholwa imisebe eminingi yelanga. Ukunyamalala okuqhubekayo kweqhwa kunciphisa i-albedo emhlabeni jikelele. Lokhu kufaka isandla ama-25% emiphumeleni eqondile yokushisa komhlaba okubangelwa ngabantu. Kuyabonakala futhi ukuthi, njengoba iqhwa lasolwandle linyamalala, iqhwa elisogwini liyancibilika ngokushesha okukhulu entwasahlobo, ngenxa yemfudumalo yomoya ovela olwandle olucwebile.
Ukukhuphuka kwamazinga olwandle
Umphumela wesibili wokuhlehla kwama-ice sheet waziwa kangcono. Kumayelana yokwenyuka kwamazinga olwandle. Iqhwa lasehlobo liyingxenye yesine kuphela yevolumu elaliyiyo ngawo-1970. Lokhu kubangela ukuba amanzi ancibilike ajikeleze eziqongweni zeqhwa aze aphelele olwandle, okwenza izinga lawo likhuphuke. Ochwepheshe be-IPCC balinganisele ukuphakama kwezinga lolwandle okungaphezu kwemitha elilodwa. Lolu wushintsho olungenakuhlehliswa oluzoba nemiphumela eyinhlekelele emadolobheni asogwini njenge-Miami, i-New York, i-Shanghai, ne-Venice, kanye nokwandisa imvamisa yezikhukhula ogwini oluyisicaba, oluminyene njenge-Bangladesh. Ungathola ulwazi olwengeziwe mayelana nemithelela ehlobene ku ukudla kwamabhere ase-polar.
Ukuze uqonde kangcono le mithelela, kubalulekile ukufunda ukuthi kanjani Ukuncibilika kwe-Antarctica kubangela ingozi esintwini.
Ukukhishwa kweMethane
Umphumela wesithathu usongo olusondele kakhulu esintwini. Ingabe mayelana ukukhishwa kwemethane olwandle. I-Arctic inohlelo lwayo lokungenisa umoya olusebenzayo inqobo nje uma kukhona ama-ice sheet ebusweni bamanzi. Ehlobo, noma ngabe kuneqhwa elincane, amazinga okushisa amanzi awakwazi ukukhuphuka ngaphezu kwama-0 degrees. Kungakho kugcinwa uhlelo lokupholisa umoya. Kodwa-ke, lapho iqhwa lincibilika ngokuphelele ehlobo, uquqaba lwamanzi lukwazi ukushisa lufinyelele kuma-degree angama-7, lumunce imisebe yelanga (ngoba alikho iqhwa eliyibonisayo). E-Arctic, amashalofu ezwekazi ajulile kakhulu, ukuze imisebe yelanga emunca amanzi ifinyelele phansi olwandle, incibilise iqhwa ebelilokhu likhona kusukela nge-Ice Age yokugcina.
Izidumbu esizithola kuqhwa lwasolwandle olunazo amanani amakhulu emethani agciniwe, ngakho-ke ukuncibilika kwayo kuzokhipha ukukhishwa kwamakholomu amakhulu e-methane. IMethane inomphumela wokushisa izulu Izikhathi ezingama-23 ezinkulu kune-carbon dioxide, ngakho ukudedelwa kwayo emkhathini kwakuzokwandisa ukufudumala kwembulunga yonke. Uma lezi zinhlayiya ze-methane zidedelwa emkhathini, kungaba nomthelela ekwenyukeni kwezinga lokushisa lomhlaba elingu-0,6 degrees ngo-2040. Ngaphezu kwalokho, ungafunda mayelana i-permafrost ne-methane.
Enye ingozi enkulu enhlalakahleni yomhlaba wethu ukuthi kungenzeka ukuthi ukufudumala kwe-Arctic nokunyamalala kweqhwa lasolwandle kuyimbangela isimo sezulu esibi kakhulu esike sabhekana naso eminyakeni eyisithupha edlule, ngobusika obubanda kakhulu noma obunesiphepho ezingxenyeni ezithile zaseYurophu naseNyakatho Melika nesimo sezulu esifudumele kakhulu kwezinye izindawo.
Ukusakaza kweJet
Kukhona ucingo ukusakaza kwejet okuyiwona ohlukanisa i-Arctic nezinqwaba zomoya ongaphansi ongaphansi. Yebo, lo mfula wejet uhamba kancane kunakuqala, ngoba umehluko wamazinga okushisa phakathi kwamanzi asezingeni eliphansi namanzi ase-Arctic anciphile. Iqiniso lokuthi ukusakazwa kwejet kuhamba kancane kuvumela ukuthi izinhlelo zezulu zezulu zesimo esisodwa zikhuliswe isikhathi esifana nokuthi isomiso, izikhukhula, amagagasi okushisa, njll.. Imiphumela emikhulu yokuhamba kancane kwalesi sikhathi yenzeka emazweni asezingeni eliphakathi nendawo enyakatho yezwe lapho kutholakala khona ipulazi elikhiqiza kakhulu emhlabeni. Uma lo mphumela uqhubeka, ukukhiqizwa kokudla komhlaba wonke kungaba sengozini enkulu, okuholele kwindlala, ukukhuphuka kwamanani okudla nezimpi.
Ibhande elihambisa olwandle
Umphumela wokugcina wokunyamalala kweqhwa ungaba nenzuzo ethile. khona ukujikeleza kancane kwe-thermohaline okungahanjiswa yimimoya, kepha kusukela ekusatshalalisweni kokushisa nemvula phezu kwezilwandle. Lokhu kusakazwa kwaziwa njenge ibhande lokuhambisa. Ngokuyisisekelo, kungumsinga lapho uquqaba lwamanzi ashisayo lusakazeka lubheke e-Arctic futhi lapho luphola phansi lube nosawoti futhi lube lukhulu. Lokhu kwanda kobuningi kubangela ukuthi uquqaba lwamanzi lucwile futhi lujikeleze futhi lubheke ezindaweni eziphansi. Lapho befika ePacific, bayafudumala futhi futhi bangabi manzi kakhulu, babuyela ngaphezulu. Yebo, endaweni lapho imizimba yamanzi icwila khona ngenxa yokubanda nokuminyana, alikho iqhwa elibonakale kusukela ngo-1998. Lokhu kwenza ibhande elihambayo liyeke ukusebenza, okwenza amanzi aphole kancane. Inzuzo engalethwa yilokhu ukuthi, ngasekupheleni kwekhulu leminyaka, i-United Kingdom, i-Ireland, i-Iceland kanye nogu lwaseFrance neNorway (ngaphezu kwenyakatho-ntshonalanga yeSpain) Zizokhuphuka ngo-2 ° C kuphela, uma kuqhathaniswa ne-4 ° C esabekayo emazweni amaningi aseYurophu. Lezi yizindaba ezinhle enyakatho-ntshonalanga yeYurophu, kepha hhayi eMelika eshisayo, ngoba ukulahleka kwamanje kuzokhuphula izinga lokushisa lamanzi e-Atlantic kuleyo ndawo futhi, ngenxa yalokho, namandla eziphepho.
Ikusasa elingenayo iqhwa
Le mininingwane ngemiphumela nemiphumela yokunyamalala kweqhwa ibaluleke kakhulu ngezizathu ezithile. Okokuqala ukuthi kukhombisa ubuze bezimpikiswano mayelana izinzuzo zezomnotho ezincibilikayo kuzodingeka ukuthi zenze lula ukuthuthwa kwezilwandle kanye nokuhlola uwoyela wasolwandle. Lesi simo singaletha ohulumeni izinzuzo eziyizigidigidi zamadola. Kodwa-ke, izindleko zokufudumala okwenza lokhu kwenzeke zibalelwa ezigidigidini zamadola.
Owesibili ukhombisa ukuthi ikusasa lokushisa komhlaba akunakwenziwa ngendlela eqondile, kucatshangelwa ukukhishwa kwe-CO2 kuphela, kodwa futhi kucatshangelwa ukuthi kunezici eziningi ezihilelekile ekusheshiseni ukufudumala futhi zingase zigcine zibusa iphethini. Ngiveze umthelela wokuncishiswa kwe-albedo kanye nokukhululwa kwe-methane ezinhlakeni zasolwandle. Yingakho kungenzeka ukuthi, ngisho noma sinciphisa ukukhishwa kwe-CO2 emhlabeni jikelele, uhlelo ngeke lisabele ngendlela efanayo ngoba amagesi abamba ukushisa ayanda emkhathini kanye nenani lokushisa elibanjwa nguMhlaba liyakhula. Ukuze uqonde kangcono lesi simo, bheka isihloko esithi i-Totten Glacier nokuncibilika kwayo.
Njengoba ukwazi ukubona, kunemiphumela emibi ekunyamalaleni kweqhwa emhlabeni. Esinye sezixazululo ezingaba khona akukhona ukunciphisa inani le-CO2 ekhishelwa emkhathini, kepha kunalokho inqubo yokumunca i-CO2 ukuyisusa kumjikelezo. Kodwa-ke, umuntu ulahlekelwa esinye sezinto eziphilayo imvelo esidinga kakhulu iplanethi futhi esisisebenzisa ukuba sibe nokuphila esingaba nakho namuhla.
