I-genesis yezigaba ezimbili-iziphepho ezinhlanu (i-Katrina ne-Rita) ngokulandelana phezu kweGulf of Mexico isenzakalo esingakaze sibe khona nesikhathazayo. Kodwa kwabaningi bezazi zezulu ezishisayo โisiphepho seshumi leminyakaโ esimangalisa ngempela senzeka ngoMashi 2004. ISiphepho uCatarina - esiqanjwe kanjalo ngoba sawela esifundeni esiseningizimu yeBrazil iSanta Catarina - kwakuyisiphepho sokuqala esirekhodiwe saseningizimu ye-Atlantic emlandweni.
I-textbook orthodoxy kade yayingabandakanyi ithuba lomcimbi onjalo; Ochwepheshe bathi amazinga okushisa olwandle ayephansi kakhulu futhi i-wind shear inamandla kakhulu ukuze ivumele izindawo ezishisayo ukuba ziguquke zibe izishingishane eningizimu ye-Atlantic Equator. Ngempela, ababikezeli bezulu bacikica amehlo abo ngokungakholwa njengoba iziphuphutheki zesimo sezulu zazixhumanisa phansi izithombe zokuqala ze-classical whirling disc neso elakheke kahle kulezi zindawo ezinqatshelwe.
Ochungechungeni lwemihlangano yakamuva kanye nokushicilelwe, abacwaningi baphikisana ngomsuka nokubaluleka kukaCatarina. Umbuzo obalulekile yilo: Ingabe uCatarina wayeyisenzakalo esiyivelakancane emaphethelweni angaphandle ejiko lensimbi elivamile lesimo sezulu saseNingizimu Atlantic - njengoba nje, ngokwesibonelo, ukushaya okumangalisayo kwemidlalo engu-56 kaJoe DiMaggio ngo-1941 kwakufanekisela amathuba adlulele ku-baseball (an Isifaniso esenziwe saduma nguStephen Jay Gould) - noma ingabe uCatarina wayeyisenzakalo "esiseduze", esibonisa ushintsho oluthile olubalulekile nolusheshayo lwesimo sezulu seplanethi?
Izingxoxo zesayensi zoshintsho lwendawo ezungezile nokufudumala kwembulunga sekuyisikhathi eside zihlushwa umbono wokungaqondile. Amamodeli wesimo sezulu, njengamamodeli wezomnotho, kulula kakhulu ukuwakha nokuwaqonda uma elula ngomugqa wokuziphatha okunenani elidlule; lapho izimbangela zigcina ukulinganiswa okungaguquki emiphumeleni yazo.
Kodwa zonke izingxenye eziyinhloko zesimo sezulu somhlaba wonke - umoya, amanzi, iqhwa, nezimila - empeleni azinamugqa: Emikhawulweni ethile zingashintsha zisuke kwesinye isimo sokuhleleka ziye kwesinye, kube nemiphumela eyinhlekelele ezinhlotsheni ezicushwe kahle kakhulu ziye ezinkambisweni zakudala. Nokho, kuze kube sekuqaleni kwawo-1990, kwakukholelwa ukuthi lezi zinguquko ezinkulu zesimo sezulu zithatha amakhulu eminyaka, uma kungezona izinkulungwane zeminyaka, ukuze zifezeke. Manje, ngenxa yokukhishwa kwekhodi kwamasiginesha acashile kuma-ice cores kanye ne-sediments ephansi kolwandle, siyazi ukuthi amazinga okushisa embulunga yonke nokujikeleza kolwandle, ngaphansi kwezimo ezifanele, kungashintsha kungazelelwe - eminyakeni eyishumi noma ngaphansi.
Isibonelo esimangalisayo yileso esibizwa ngokuthi "i-Younger Dryas", eminyakeni engu-12,800 edlule, lapho idamu leqhwa lawa, lakhipha umthamo omkhulu wamanzi ancibilikayo asuka ku-Laurentian ice-sheet olwandle i-Atlantic Ocean ngomfula i-St. Lawrence owadalwa ngokushesha. . Lokhu โkuqabulaโ kweNyakatho ye-Atlantic kwacindezela ukuhanjiswa kwamanzi afudumele aye enyakatho yiGulf Stream futhi kwabuyisela iYurophu enkathini yeqhwa yeminyaka eyinkulungwane.
Izindlela zokushintsha ngokuzumayo ohlelweni lwesimo sezulu - njengoshintsho oluncane kusawoti olwandle - zengezwa izihibe eziyimbangela esebenza njengezikhulisi. Mhlawumbe isibonelo esidume kakhulu i-sea-ice albedo: Udedangendlale weqhwa lase-Arctic Ocean elimhlophe, eliyiqhwa libonisa ukushisa kubuyele emkhathini, ngaleyo ndlela kunikeze impendulo eyakhayo mayelana nezitayela zokupholisa; okunye, ukushwabana kweqhwa olwandle kwandisa ukumuncwa kokushisa, kusheshise kokubili ukuncibilika kwalo okuqhubekayo nokufudumala kweplanethi.
Ama-Thresholds, switch, amplifiers, chaos - i-contemporary geophysics ithatha ngokuthi umlando womhlaba unoguquko ngokwemvelo. Yingakho abacwaningi abaningi abavelele - ikakhulukazi labo abafunda izihloko ezifana nokuzinza kwe-ice-sheet kanye nokujikeleza kwe-North Atlantic - bebelokhu benokungabaza mayelana nokuqagela kokuvumelana kwe-Intergovernmental Panel on Climate Change (IPCC), igunya lomhlaba mayelana nokufudumala kwembulunga yonke.
Ngokuphambene nama-Bushite flat-Earthers kanye namashill embonini kawoyela, ukungabaza kwabo kusekelwe ekwesabeni ukuthi amamodeli e-IPCC ahluleka ukuvumela ngokwanele ukungafani okuyinhlekelele njenge-Younger Dryas. Lapho abanye abacwaningi bemodela khona isimo sezulu sakamuva sekhulunyaka lama-21 izingane zethu ezizohlala naso ngesikhathi se-Altithermal (isigaba esishisa kakhulu senkathi yamanje yeHolocene, eminyakeni engu-8,000 edlule) noma i-Eemian (isiqephu esedlule, esifudumele nakakhulu se-interglacial, iminyaka eyi-120,000. edlule), izinombolo ezikhulayo zezazi ze-geophysicist zidlala ngamathuba okufudumala okubalekayo abuyisela umhlaba esiphithiphithini esishisayo se-Paleocene-Eocene Thermal Maximum (PETM: eminyakeni eyizigidi ezingu-55 edlule) lapho ukushisa okukhulu nokushesha kwezilwandle kuholela ekuqothulweni okukhulu.
Kusanda kuvela ubufakazi obusha obushaqisayo bokuthi kungenzeka sibheke, uma singabuyeli kwesabekayo, i-PETM cishe engenakucatshangwa, bese sifika endaweni enzima kakhulu kunalokho okwakucatshangwa yi-IPCC.
Njengoba ngindizela eLouisiana kanye nokucekelwa phansi kukaKatrina emasontweni amathathu edlule, ngazithola sengifunda umagazini ka-August 23 EOS, iphephandaba le-American Geophysical Union. Ngishiswe yi-athikili enesihloko esithi โArctic System on Trajectory to New, Seasonally Ice-Free State,โ eyabhalwa ngokubambisana ososayensi abangama-21 abavela emanyuvesi cishe amaningi nezikhungo zocwaningo. Ngisho nangemva kwezinsuku ezimbili, ngihamba phakathi kwamanxiwa e-Lower Ninth Ward, ngazithola ngikhathazeka kakhulu nge- EOS isihloko kunenhlekelele engizungezile.
I-athikili iqala ngokulandisa kabusha kwezitayela ezijwayelekile kunoma yimuphi umfundi wesigaba sesayensi sangoLwesibili se- New York Times: Sekuyiminyaka engaba ngu-30, iqhwa lasolwandle i-Arctic lincipha futhi lincipha ngendlela ephawulekayo kangangokuthi โi-Arctic Ocean engenaqhwa ehlobo phakathi nekhulu leminyaka yinto engenzeka ngempela.โ Ososayensi, nokho, bengeza umbono omusha - wokuthi le nqubo cishe ayinakubuyela emuva. Kuyamangaza ukuthi kunzima ukuhlonza indlela eyodwa yempendulo ngaphakathi kwe-Arctic enamandla noma isivinini sokushintsha inkambo yamanje yesistimu.
I-Arctic Ocean engenaqhwa ayikaze ibe khona okungenani iminyaka eyisigidi futhi ababhali baxwayisa ngokuthi uMhlaba uphokophele esimeni โesiphakathi kwezinguzunga zeqhwaโ โngaphandle kwemvilophi yokuguquguquka kweglacial-interglacial okukhona phakathi nomlando wakamuva woMhlaba.โ Bagcizelela ukuthi phakathi nekhulu leminyaka ukufudumala kwembulunga yonke cishe kuzokweqa izinga lokushisa le-Eemian futhi ngaleyo ndlela kugweme wonke amamodeli awenze lesi simo sawo esibalulekile. Baphinde baphakamise ukuthi ukubhidlika okuphelele noma ingxenye ye-Greenland Ice Sheet yinto engenzeka ngempela - umcimbi ongaphonsa isikrufu se-Younger Dryas ku-Gulf Stream.
Uma beqinisile, kusho ukuthi siphila esimweni sezulu esilingana nesitimela esibalekayo esidlondlobala ngesivinini njengoba sidlula eziteshini ezibhalwe ukuthi โAltithermalโ nokuthi โEemian.โ โNgaphandle kwemvilophi,โ ngaphezu kwalokho, kusho ukuthi asishiyi nje kuphela izimo zezulu ezidabukisayo zeHolocene - iminyaka eyi-10,000 yokugcina yesimo sezulu esipholile esivuse ukukhula kwezolimo kanye nempucuko yasemadolobheni - kodwa nalezo ze I-Pleistocene engasekho eyakhuthaza ukuvela kweHomo sapiens empumalanga ye-Afrika.
Abanye abacwaningi ngokungangabazeki bazophikisana neziphetho ezingavamile ze- EOS i-athikili futhi - kufanele sethembe - iphakamisa ukuba khona kwamandla aphikisayo kulesi simo senhlekelele ye-Arctic albedo. Kepha okwamanje, okungenani, ucwaningo ngoguquko lomhlaba lukhomba ezimweni ezimbi kakhulu.
Konke lokhu, vele, kuwukuhlonipha okuphambene ne-industrial capitalism kanye ne-extractive imperialism njengamandla omhlaba anamandla kangangokuthi baye baphumelela cishe eminyakeni engamakhulu amabili - ngempela, ikakhulukazi eminyakeni engamashumi amahlanu edlule - ekususeni umhlaba endaweni yawo yesimo sezulu. futhi uyiqhubekisela endaweni engaziwa.
Idemoni elikimi lifuna ukuthi: Iphathi futhi nijabule. Asikho isidingo manje sokukhathazeka nge-Kyoto, ukugaywa kabusha kwamathini akho e-aluminium, noma ukusebenzisa iphepha lasendlini yangasese eliningi, lapho, maduze nje, sizobe sidingida ukuthi bangaki abazingeli abangabaqoqi abangasinda ezingwadule ezishisayo zaseNew England noma emahlathini ashisayo I-Yukon.
Nokho, umzali omuhle okimi uyaklabalasa: Kungenzeka kanjani ukuthi manje sicabange ngokujulile ngokwesayensi ukuthi izingane zezingane zethu zizoba nazo yini izingane? Vumela i-Exxon iphendule lokho kwesinye sezikhangiso zabo ezingcwele.
Copyright 2005 Mike Davis
UMike Davis ungumbhali wezincwadi eziningi ezihlanganisa Idolobha laseQuartz, Amadolobha Afile kanye Nezinye Izinganekwane, kanye nesanda kushicilelwa Inunu Emnyango Wethu, Usongo Lomhlaba Wonke Lomkhuhlane Wezinyoni (I-New Press) kanye nezizayo Iplanethi Yemijondolo (Verso).
[Le ndatshana yaqala ukuvela ngo I-Tomdispatch.com, ibhulogi yewebhu ye-Nation Institute, enikeza ukugeleza okuqhubekayo kweminye imithombo, izindaba, kanye nemibono evela ku-Tom Engelhardt, umhleli wesikhathi eside ekushicilelweni, Umsunguli we- i-American Empire Project nombhali Ukuphela KweMasiko Okunqoba.]
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