Ubungakanani beoksijini emanzini eplanethi yethu buyancipha ngokukhawuleza nangokumangalisayo—ukusuka emachibini ukuya elwandle. Ukulahleka okuqhubekayo kweoksijini akusongeli nje kuphela iindawo eziphilayo, kodwa kusongela nobomi bamacandelo amakhulu oluntu kunye neplanethi yonke, ngokutsho kwababhali besifundo samazwe ngamazwe esibandakanya i-GEOMAR esipapashwe namhlanje kwi-Nature Ecology & Evolution.
Bafuna ukuba ukulahleka kweoksijini emanzini kuqatshelwe njengomda weplanethi ukuze kugxilwe ekujongeni ihlabathi, kuphando nakwimilinganiselo yezopolitiko.
Ioksijini yimfuneko ebalulekileyo yobomi kwiplanethi yoMhlaba. Ukulahleka kweoksijini emanzini, okubizwa ngokuba yi-aquatic deoxygenation, kuyingozi kubomi kuzo zonke iinqanaba. Iqela labaphandi bamazwe ngamazwe lichaza indlela i-deoxygenation eqhubekayo ebeka ngayo umngcipheko omkhulu kwindlela yokuphila yamalungu amaninzi oluntu kunye nokuzinza kobomi kwiplanethi yethu.
Uphando lwangaphambili luchonge uluhlu lweenkqubo zesikali sehlabathi, ezibizwa ngokuba yimida yeeplanethi, ezilawula ukuhlala kunye nokuzinza kweplanethi iyonke. Ukuba imida ebalulekileyo kwezi nkqubo iyaphunyezwa, umngcipheko wotshintsho olukhulu, olukhawulezileyo okanye olungenakuguqulwa kwindalo ("amanqaku okujika") uyanda kwaye ukuqina kweplanethi yethu, ukuzinza kwayo, kuyasengozini.
Phakathi kwemida yeeplanethi ezisithoba kukho utshintsho lwemozulu, utshintsho lokusetyenziswa komhlaba, kunye nokulahleka kwezinto eziphilayo ezahlukeneyo. Ababhali bolu phononongo lutsha bathi ukususwa kweoksijini emanzini kuyasabela, kwaye kulawula, ezinye iinkqubo zemida yeeplanethi.
“Kubalulekile ukuba ukukhutshwa kweoksijini emanzini kongezwe kuluhlu lwemida yeeplanethi,” utshilo uNjingalwazi uGqr. Rose waseRensselaer Polytechnic Institute eTroy, eNew York, umbhali ophambili wale ncwadi. “Oku kuya kunceda ekuxhaseni nasekugxileni esweni kwehlabathi, uphando, kunye nemizamo yemigaqo-nkqubo yokunceda iinkqubo zethu zendalo zasemanzini, kwaye, uluntu ngokubanzi.”
Kuzo zonke iindawo eziphilayo zasemanzini, ukusuka kwimilambo nemilambo, amachibi, amachibi, namachibi ukuya kwiindawo zokungena kwamanzi, unxweme, kunye nolwandle oluvulekileyo, ubuninzi beoksijini enyibilikisiweyo buye behla ngokukhawuleza nangokubonakalayo kwiminyaka yakutshanje.
Amachibi kunye namachibi olwandle alahlekelwe yioksijini nge-5.5% kunye ne-18.6% ngokulandelelanayo ukusukela ngo-1980. Ulwandle lulahlekelwe yioksijini nge-2% ukusukela ngo-1960. Nangona eli nani livakala lincinci, ngenxa yobuninzi bolwandle, limele ubunzima obukhulu beoksijini elahlekileyo.
Iinkqubo zemvelo zaselwandle nazo ziye zafumana utshintsho olukhulu ekuncipheni kweoksijini. Umzekelo, amanzi aphakathi eCentral California alahlekelwe yi-40% yeoksijini yawo kwiminyaka embalwa edlulileyo. Ubuninzi beenkqubo zemvelo zasemanzini ezichaphazeleka kukuncipha kweoksijini bunyuke kakhulu kuzo zonke iintlobo.
“Izizathu zokulahleka kweoksijini emanzini kukufudumala komhlaba ngenxa yokukhutshwa kwegesi ezibangela ukufudumala komhlaba kunye nokufakwa kwezondlo ngenxa yokusetyenziswa komhlaba,” utshilo umbhali-mbhali uGqr. Andreas Oschlies, uNjingalwazi weMarine Biogeochemical Modelling kwi-GEOMAR Helmholtz Centre for Ocean Research Kiel.
"Ukuba amaqondo obushushu bamanzi ayanyuka, ukunyibilika kweoksijini emanzini kuyancipha. Ukongeza, ukufudumala kwehlabathi kuphucula ukuhluma kwekholamu yamanzi, kuba amanzi afudumeleyo, anetyuwa encinci anobunzima obuphantsi ahlala phezu kwamanzi abandayo nanzulu anetyuwa engaphezulu."
"Oku kuthintela ukutshintshiselana kweengqimba ezinzulu ezingenayo ioksijini namanzi angaphezulu atyebileyo ioksijini. Ukongeza, izakhamzimba ezivela emhlabeni zixhasa ukuqhakaza kwe-algal, nto leyo ekhokelela ekubeni ioksijini engakumbi isetyenziswe njengoko izinto eziphilayo zitshona kwaye zibola ziintsholongwane ebunzuluni."
Iindawo elwandle apho kukho ioksijini encinci kangangokuba iintlanzi, iimbaza okanye ii-crustaceans azikwazi kusinda zisongela kungekuphela nje izinto eziphilayo ngokwazo, kodwa neenkonzo zendalo ezifana nokuloba, ukulima iintlanzi, ukhenketho kunye nezenzo zenkcubeko.
Iinkqubo ze-microbiotic kwiindawo eziphelelwe yioksijini nazo zivelisa ngakumbi iigesi ezinamandla ze-greenhouse ezifana ne-nitrous oxide kunye ne-methane, nto leyo enokubangela ukwanda kobushushu behlabathi kwaye ngaloo ndlela ibe yimbangela enkulu yokuncipha kweoksijini.
Ababhali bayalumkisa: Sisondela kwimida ebalulekileyo yokukhupha ioksijini emanzini eya kuthi ekugqibeleni ichaphazele eminye imida yeeplanethi.
UNjingalwazi uGqr. Rose uthi, “Ioksijini enyibilikisiweyo ilawula indima yolwandle kunye namanzi acocekileyo ekuguquleni imozulu yoMhlaba. Ukuphucula ubuninzi beoksijini kuxhomekeke ekujongeni izizathu eziphambili, kuquka ukufudumala kwemozulu kunye nokuchitheka kwamanzi avela kwiindawo eziphuhlileyo.
"Ukusilela ukujongana nokususwa kweoksijini emanzini, ekugqibeleni, akuyi kuchaphazela kuphela iinkqubo zendalo kodwa kuya kuchaphazela nomsebenzi wezoqoqosho, kunye noluntu kwinqanaba lehlabathi."
Iindlela zokukhupha ioksijini emanzini zimele isilumkiso esicacileyo kunye nesimemo sokuba kwenziwe into ekufuneka ikhuthaze utshintsho lokucothisa okanye ukunciphisa lo mda weplanethi.
Inzwa yeoksijini enyibilikisiweyo yomgangatho wamanzi
Ixesha lokuthumela: Okthobha-12-2024