Yizindaba ezindala, ngiyavuma. Iminyaka eyizigidi ezingamakhulu amabili namashumi amahlanu nanye ubudala, ukunemba. Kodwa indaba yalokho okwenzeka ngaleso sikhathi, osekukhulunywe ngayo okokuqala, idinga ukunakwa kwethu ngokushesha. Imithelela yayo ijule kakhulu kunanoma yini eyenzekayo e-Iraq, noma eWashington, noma ngisho (futhi ngiyaxolisa ukuqhuma ibhamuza lakho) Wimbledon. Ngaphandle uma siqonda okwenzekile, futhi senze ngokuvumelana nalobo buhlakani, umlando wangaphambili ungase uziphinde ngokushesha, hhayi njengenhlekelele, kodwa njengenhlekelele.
Izehlakalo ezilethe isikhathi sePermian (phakathi kweminyaka engama-286 nezingu-251 edlule) azikwazanga ukucaciswa ngokucacile kuze kube sekuqediwe ukuqoshwa kwemephu yokulandelana okubalulekile kokwakheka komhlaba. Kuze kube muva nje, izazi ze-paleeontologists bezicabange ukuthi izinguquko ezenzeka ngaleso sikhathi zazihamba kancane futhi ziyingxenye. Kodwa eminyakeni emithathu edlule kwamiswa usuku oluqondile lokuphela kwaleso sikhathi, okwenza izazi zesayensi yokwakheka komhlaba zithole ukuqhathanisa okuqondile phakathi kwamadwala ayebekwe ngaleso sikhathi ezingxenyeni ezihlukahlukene zomhlaba.
Sebekwenzile lokho, bathola into eshaqisayo. E-China, eNingizimu Afrika, e-Australia, eGreenland, eRussia naseSpitsbergen, amadwala aqopha ukulandelana okucishe kufane kwezehlakalo, ezenzeka hhayi kancane kancane, kodwa cishe ngaso leso sikhathi. Zibonisa ukuthi inhlekelele eyabangelwa izinqubo zemvelo yacishe yaqeda ukuphila emhlabeni. Baphinde basikisele ukuthi isethi yemisebenzi yabantu esongela ukuphindaphinda lezo zinqubo ingaba nomphumela ofanayo, phakathi nesikhathi sokuphila sabanye balabo abasemhlabeni namuhla.
Njengoba uprofesa we-paleeontology uMichael Benton ebhala encwadini yakhe entsha ethi, When Life Nearly Died, izinsalela zasolwandle ezifakwe ekupheleni kwenkathi yePermian ziqopha izinguquko ezimbili ezingazelelwe.1 Eyokuqala ukuthi idwala elibomvu noma eliluhlaza noma elimpunga elibekwe phansi ukuba khona komoya-mpilo kungazelelwe kuthathelwe indawo udaka olumnyama lolo hlobo olufakwa lapho umoya-mpilo ungekho. Ngesikhathi esifanayo, ukushintsha okusheshayo kwesilinganiso sama-isotopes (amanye amafomu) ekhabhoni emadwaleni kuphakamisa ushintsho olumangalisayo ekuhlanganiseni kwamagesi asemoyeni.
Ezweni, olunye uguquko olumangalisayo lubhalwe ngesikhathi esifanayo. ERussia naseNingizimu Afrika, amatshe odaka nama-limestone abekwe ngobumnene avele athathelwe indawo indawo enkulu yokulahlwa kwamatshe namatshe amakhulu. Kodwa izinguquko zokuma komhlaba zincane uma ziqhathaniswa nalokho okwenzeka ezilwaneni nasezitshalweni.
I-Permian yayingesinye sezinkathi ezihluke kakhulu zezinto eziphilayo emlandweni womhlaba. Izilwane ezihuquzelayo ezinotshani ezilingana nobhejane zazizingelwa emahlathini ezihlahla ze-fern nezihlahla eziqhakazayo yizilwane ezizingelayo ezinama-saber-toothed. Olwandle, kwanqwabelana izixhobo zamakhorali ezinkulu, phakathi kwazo okwakuhlala oshaka abakhulu, izinhlanzi zazo zonke izinhlobo kanye namakhulu ezinhlobo zezidalwa ezinamagobolondo.
Khona-ke kungazelelwe cishe akukho lutho. Umlando wezinsalela ucishe uphele. Izixhobo zezixhobo ziyafa ngokushesha, futhi aziphinde zivele emhlabeni iminyaka eyizigidi eziyishumi. Bonke oshaka abakhulu nabaphakathi bayanyamalala, iningi lezinhlobo zamagobolondo, ngisho neningi lezinto eziphilayo eziqinile neziningi kakhulu olwandle, i-plankton. Phakathi kwezigaba eziningi zezilwane zasolwandle, okuwukuphela kwento eyasinda yilezo ezajwayela ukuntuleka komoya-mpilo.
Ezweni, ukushintsha kwaba nzima nakakhulu. Impilo yezitshalo yacishe yaqedwa emhlabeni. Izilwane ezinezinyawo ezine, isigaba abantu abayingxenye yaso, zacishe zaqothulwa: kuze kube manje izinhlobo ezimbili kuphela zezilwane ezihuquzelayo ezitholakale noma kuphi emhlabeni ezisinde ekupheleni kwePermian. Ubuso bomhlaba babuswa esinye nje salezi, isilwane esifana nengulube. Yagcwala yonke indawo ngoba akukho okunye okwasala ukuncintisana nayo noma ukuyidla.
Sekukonke, u-Benton ukhombisa, cishe amaphesenti angama-90 ezinhlobo zezilwane zomhlaba abonakala eqothuliwe: lokhu kumelela ukushabalala okukhulu kakhulu. โUkukhiqizaโ komhlaba (inani eliphelele lezinto eziphilayo) kwehle.
Ama-ecosystem alulame kancane kakhulu. Azikho izixhobo zamakhorali eziye zatholakala noma kuphi emhlabeni emadwaleni abekwe phansi eminyakeni eyizigidi eziyi-10 elandelayo. Iminyaka eyizigidi eziyikhulu namashumi amahlanu yadlula ngaphambi kokuba umhlaba uphinde ube yizinhlobonhlobo zezinto eziphilayo njengoba kubonakala sengathi wawusePermian. Pho kwenzekani?
Abanye ososayensi baye baphikisa ngokuthi ukushabalala okukhulu kwabangelwa i-meteorite. Kodwa ubufakazi ababubekayo buye babukela phansi ezinye izifundo. Kukhona icala eliheha kakhulu lencazelo ehlukile. Sekuyiminyaka eminingi, izazi zokuma komhlaba zazi ukuthi esikhathini esithile phakathi noma ngemva kwePermian kwakukhona uchungechunge lwezintaba-mlilo ezinkulu eSiberia. I-lava yabhalwa ngendlela efanele okokuqala ngqa ekuqaleni kwawo-1990. Manje siyazi ukuthi ukuqhuma okuyinhloko kwenzeka eminyakeni eyizigidi ezingu-251 edlule, ngaso leso sikhathi lapho ukuphila kwase kucishe kwacisha khona.
Izintaba-mlilo zakhiqiza amagesi amabili: i-sulphur dioxide ne-carbon dioxide. Isibabule nokunye okuphumayo kubangele imvula ene-asidi, kodwa bekuzophuma igazi emkhathini ngokushesha okukhulu. Ngakolunye uhlangothi, isikhutha ngabe saqhubeka. Ngokuthuthukisa umphumela we-greenhouse, kubonakala sengathi kufudumeze umhlaba ngokwanele ukuba kuthuntubeze igesi eqandiswe kakhulu ebizwa ngokuthi i-methane hydrate, evalelwe olwandle olwandle olushisayo. Ukukhishwa kwe-methane emkhathini kuchaza ukushintsha okungazelelwe kwe-carbon isotopes.
I-Methane iyigesi ebamba ukushisa enamandla kakhulu kune-carbon dioxide. Umphumela wokukhululwa kwawo kwaba ukufudumala kwembulunga yonke okubalekayo: ukwenyuka kwezinga lokushisa kwaholela ezinguqukweni ezikhuphule izinga lokushisa ngokuqhubekayo, nokunye. Ukufudumala kubonakala, eduze kwemvula ene-asidi, kubulale izitshalo. Indlala yabe isibulala izilwane.
Ukufudumala kwembulunga yonke kubonakala kuchaza izinguquko ze-geological. Uma izinga lokushisa kwamanzi angaphezulu eduze kwezigxobo likhuphuka, ukujikeleza kwemisinga yasolwandle kuncipha, okusho ukuthi indawo engaphansi kolwandle ayinawo umoya-mpilo. Njengoba izitshalo ezisemhlabeni zifa, izimpande zazo zizoyeka ukubamba ndawonye inhlabathi namadwala axegayo, okube nomphumela wokuthi izinga lokuguguleka kwenhlabathi likhuphuke kakhulu. Ngakho kungakanani ukushisa okwenzeka? Ukushintsha okubukhali kwesilinganiso sama-isotopes omoya-mpilo kusivumela ukuthi siphendule ngokunemba okuthile: ama-degree centigrade ayisithupha. U-Benton akalivezi leli phuzu elisobala, kodwa omunye umbhali, isazi sokuguquguquka kwesimo sezulu uMark Lynas, uyakwenza.2 Ama-degree ayisithupha isilinganiso esiphezulu esikhiqizwe uphiko lwesayensi lwe-UN, i-Intergovernmental Panel on Climate Change, mayelana nokufudumala kwembulunga yonke ngo-2100.3
Ingqungquthela yososayensi bomkhathi abahamba phambili emhlabeni eBerlin ngenyanga edlule yaphetha ngokuthi kungenzeka ukuthi imodeli ye-IPCC yayiyithathe kancane le nkinga: umkhawulo ongaphezulu, manje basikisela ukuthi, kufanele ube phakathi kuka-7 no-10 degrees.4 Ayikho imodeli ecabangela ukuthi kungenzeka ukuncibilika ngokwengxenye kwe-methane hydrate kusekhona ngobuningi emaphethelweni olwandle olupholile.
Kungazelelwe, izehlakalo zengxenye yenkulungwane yezigidigidi zeminyaka edlule ziqala ukubukeka njengezihloko ngempela. Esinye seziphetho ezingase zibe khona zendaba yomuntu sekushiwo kakade. Umzamo wethu omkhulu wezepolitiki manje kufanele kube wukuqinisekisa ukuthi akubeki phansi. Incwadi kaGeorge Monbiot ethi The Age of Consent: a Manifesto for a New World Order ishicilelwe ngabakwaFlamingo. www.monbiot.com Izithenjwa:
1. UMichael J. Benton, 2003. Lapho Ukuphila Kucishe Kwafa: Ukuqothulwa Kwenqwaba Enkulu Kunazo Zonke Isikhathi. I-Thames ne-Hudson, eLondon.
2. I-Press Release ekhishwe ngu-Mark Lynas, 17th June 2003. "Ubufakazi Obusha Buxwayisa 'Ngenhlekelele' Yokufudumala Kwembulunga yonke kuleli khulu Leminyaka".
3. Eg Robert Watson, usihlalo IPCC, 20th November 2000. Bika Engqungqutheleni Yesithupha Yamaqembu Enhlangano Yezizwe Ezihlangene Yohlaka Lokuguquguquka Kwesimo Sezulu. 4. UFred Pearce, 4th June 2003. I-Global Warming's Sooty Smokescreen Sembulwa. Usosayensi Omusha. http://www.newscientist.com/news/news.jsp?id=ns99993798