Izinyathelo Zokuthumela Ngemikhumbi Okuqhubekayo

Njengoba uhwebo olusekelwe olwandle lukhula, kanjalo nesizinda sakho semvelo siyakhula. Ngenxa yobukhulu bokuhwebelana kwembulunga yonke, umkhumbi ubangela izingxenye ezibalulekile zokukhishwa kwesikhutha, ukushayisana kwezilwane ezincelisayo zasolwandle, umoya, umsindo, nokungcoliswa kwepulasitiki, kanye nokusabalala kwezinhlobo ezihlaselayo. Ngisho nasekupheleni kokuphila komkhumbi kungase kube nokukhathazeka okuphawulekayo kwemvelo kanye namalungelo abantu ngenxa yemikhuba eshibhile nengenanembeza yokugqekeza umkhumbi. Nokho, kunamathuba amaningi okubhekana nalezi zinsongo.

Imikhumbi Iyisongela Kanjani Imvelo Yasolwandle?

Imikhumbi ingumthombo omkhulu wokungcola komoya, okuhlanganisa namagesi abamba ukushisa. Ucwaningo luthole ukuthi imikhumbi ehamba ngomkhumbi evakashela amachweba eYurophu inikela ngenani eliningi le-carbon dioxide emvelweni njengazo zonke izimoto kulo lonke elaseYurophu. Muva nje, kube nokuphushwa kwezindlela ezisimeme zokuqhubekisela phambili ezizonciphisa ukungcola. Nokho, ezinye izixazululo ezihlongozwayo - njengegesi yemvelo ewuketshezi (LNG) - zicishe zibe zimbi endaweni ezungezile njengegesi yendabuko. Nakuba i-LNG ikhiqiza i-carbon dioxide encane kunezibaseli zikawoyela osindayo wendabuko, ikhipha i-methane eyengeziwe (amaphesenti angama-84 egesi ebamba ukushisa enamandla) emkhathini. 

Izilwane zasolwandle zisaqhubeka nokulimala okubangelwa ukushaywa kwemikhumbi, ukungcoliswa komsindo nezinto zokuhamba eziyingozi. Emashumini amane eminyaka adlule, imboni yemikhumbi ibone ukwanda okuphindwe kathathu kuya kane kwenani leziteleka ezibikiwe zemikhumbi yemikhomo emhlabeni wonke. Kokubili ukungcoliswa komsindo ongapheli ovela ezinjinini nasemishinini kanye nokunukubezeka komsindo oshubile ovela ezindaweni zokumba ngaphansi kwamanzi, izinhlolovo zokuzamazama komhlaba, kungase kusongela ukuphila olwandle olwandle ngokufihla ukuxhumana kwezilwane, ukuphazamisa ukuzala, futhi kubangele amazinga aphezulu okucindezeleka ezidalwa zasolwandle. Ngaphezu kwalokho, kunezinkinga ngezimo ezinyantisayo zezigidi zezilwane zasemhlabeni ezithuthwa ngemikhumbi unyaka ngamunye. Lezi zilwane zizimela emfucumfucwini wazo, zilimale ngokunyakaziswa amagagasi emikhumbi, futhi ziminyene ezindaweni ezingenawo umoya ohlanzekile amasonto amaningi ngesikhathi. 

Ukungcoliswa kwepulasitiki okutholakala emikhunjini kuwumthombo okhulayo wokungcola kwepulasitiki olwandle. Amanetha epulasitiki kanye nemishini evela ezikebheni zokudoba kuyalahlwa noma kulahleke olwandle. Izingxenye zomkhumbi, ngisho nezincane, imikhumbi ehamba olwandle, ziya ngokuya zenziwe ngamapulasitiki, okuhlanganisa kokubili okuhlanganisa kokubili okuqiniswe ngefayibha kanye ne-polyethylene. Nakuba izingxenye zepulasitiki ezingasindi zinganciphisa ukusetshenziswa kukaphethiloli, ngaphandle kokwelashwa kokuphela kokuphila okuhleliwe, le pulasitiki ingase igcine ingcolise ulwandle amakhulu eminyaka ezayo. Amapende amaningi avimbela ukubola aqukethe ama-polymers epulasitiki ukwelapha imikhumbi yemikhumbi ukuvimbela ukungcola noma ukunqwabelana kokukhula kwendawo, okufana ne-algae nama-barnacles. Okokugcina, imikhumbi eminingi ilahla ngokungafanele imfucuza ekhiqizwe ebhodini, kanye nepulasitiki esekelwe emkhunjini okukhulunywe ngayo ngaphambili, okuwumthombo omkhulu wokungcoliswa kwepulasitiki olwandle.

Imikhumbi iklanyelwe ukuthatha amanzi ukuze ibhalansise futhi izinze lapho imithwalo yempahla ilula ngokuthatha amanzi e-ballast ukuze isuse isisindo, kodwa la manzi e-ballast angase alethe abagibeli abangahlosiwe ngesimo sezitshalo nezilwane ezitholakala emanzini e-ballast. Kodwa-ke, uma amanzi e-ballast ehlala enganakiwe, ukwethulwa kwezinhlobo ezingezona ezomdabu kungadala umonakalo emvelweni wemvelo lapho amanzi ekhishwa. Ukwengeza, amanzi e-ballast kanye namanzi angcolile akhiqizwa imikhumbi awahlali ephathwa ngendlela efanele futhi ngokuvamile alahlwa emanzini azungezile kuyilapho esagcwele ukungcola nezinto zangaphandle, okuhlanganisa amahomoni nezinye izinsalela zemithi yabagibeli, okungase kubangele ukulimala endaweni ezungezile. Kuningi okudingeka kwenziwe ukuze kuqinisekiswe ukuthi amanzi aphuma emikhunjini ahlanzeke ngendlela efanele. 

Ekugcineni, zikhona ukwephulwa kwamalungelo abantu okuhlobene nayo ukugqekeza umkhumbi; inqubo yokudiliza umkhumbi ube izingxenye ezigaywa kabusha. Ukugqekeza imikhumbi emazweni asathuthuka kuwumsebenzi onzima, oyingozi, futhi okhokha kancane onezivikelo zokuphepha ezincane noma azikho nhlobo zabasebenzi. Nakuba ukugqekeza umkhumbi kuvame ukuhambisana nemvelo kunokumane uzike noma ushiye umkhumbi ekupheleni kokuphila kwawo, kuningi okudingeka kwenziwe ukuze kuvikelwe abasebenzi abagqekeza umkhumbi futhi kuqinisekiswe ukuthi izingane zivikelekile futhi aziqashwa ngokungemthetho. Ngaphezu kokuhlukunyezwa kwamalungelo abantu, kuvame ukushoda kwemithetho yezemvelo emazweni amaningi lapho ukugqekezwa kwemikhumbi kwenzeka khona okuvumela ubuthi buphume emikhunjini bungene endaweni ezungezile.

Yimaphi Amathuba Akhona Okwenza Ukuthunyelwa Kwemikhumbi Kuzinze Kakhudlwana?

• Ukukhuthaza ukwamukelwa kwemikhawulo yesivinini ephoqelelayo kanye nokunciphisa isivinini ezindaweni ezinamazinga aphezulu eziteleka zemikhumbi yezilwane zasolwandle kanye nenani lezilwane zasolwandle ezisengozini. Ijubane elincane lemikhumbi liphinde linciphise ukukhishwa kwesisi esibamba ukushisa, linciphise ukungcoliswa komoya, linciphise ukusetshenziswa kukaphethiloli, futhi andise nokuphepha emkhunjini. Ukuze kuncishiswe ukungcoliswa komoya, imikhumbi ingase isebenzise imikhumbi ngesivinini esincane ukuze kuncishiswe ukusetshenziswa kukaphethiloli kanye nokunciphisa ukukhishwa kwekhabhoni ngenqubo eyaziwa ngokuthi ukuhamba kancane ngesitimu. 
• Ukwenyuswa kokutshalwa kwezimali ezindleleni ezisimeme zokuqhubela imikhumbi okuhlanganisa, kodwa kungagcini nje: oseyili, ama-altitude kites, namasistimu okuqhubela phambili asekelwa ugesi.
• Izinhlelo ezingcono zokuzulazula zingase zinikeze ukuhamba ngendlela efanele ukuze kugwenywe izindawo eziyingozi, kutholwe izindawo ezibalulekile zokudoba, ukulandelela ukufuduka kwezilwane ukuze kuncishiswe imithelela, kuqinisekiswe ukuthotshelwa kwemithetho, futhi kunciphise isikhathi umkhumbi usolwandle—futhi ngaleyo ndlela, sinciphise isikhathi umkhumbi ungcolisa ngaso.
• Yakha noma unikeze izinzwa ezingasetshenziswa ukuqoqa idatha yolwandle. Imikhumbi eqoqa ngokuzenzekelayo amasampula amanzi inganikeza ukuqapha kwesikhathi sangempela kanye nokuhlolwa kwekhemistri ukusiza ukugcwalisa izikhala zolwazi mayelana nezimo zolwandle, imisinga, amazinga okushisa ashintshayo, nezinguquko zekhemistri yolwandle (okufana ne-acidification yolwandle).
• Dala amanethiwekhi e-GPS ukuze uvumele imikhumbi ukuthi imake inqwaba yamaplastiki amancane, izinto zokudoba izipoki, nemfucumfucu yasolwandle. Imfucumfucu ingase ilandwe yiziphathimandla nezinhlangano ezingekho ngaphansi kukahulumeni noma iqoqwe yilabo abasembonini yemikhumbi ngokwayo.
• Hlanganisa ukwabelana ngedatha okusekela ubudlelwano phakathi kwalabo abasembonini yezokuthutha, ososayensi, nabakhi bezinqubomgomo. 
• Sebenza ukuze kusetshenziswe izindinganiso zamazwe ngamazwe eziqinile zokuhlanzeka kwamanzi e-ballast kanye namanzi angcolile ukuze kuliwe nokusabalala kwezinhlobo ezihlaselayo.
• Thuthukisa umthwalo wemfanelo owandisiwe womkhiqizi lapho izinhlelo zokuphela kwempilo zicatshangelwa kusukela ekwakhiweni kokuqala kwemikhumbi.
• Dala izindlela zokwelapha ezintsha zamanzi angcolile namanzi e-ballast aqinisekisa ukuthi azikho izinhlobo zezilwane ezihlaselayo, udoti, noma imisoco ekhishelwa ngaphandle kwemvelo endaweni.

Le bhulogi ithathwe esahlukweni esithi Greening the Blue Economy: A Transdisciplinary Analysis eshicilelwe kwethi Sustainability in the Marine Domain: Towards Ocean Governance and Beyond, ed. Carpenter, A., Johansson, T, and Skinner, J. (2021).