URETSE inkuru z’impimbano kandi ziteye ubwoba zivuga iby’imperuka zavuzwe mu ngingo ibanziriza iyi, hari ibindi bintu bihangayikishije abantu wagombye kuzirikana. Abantu benshi bahangayikishijwe n’ubwiyongere bukabije bw’abaturage, bushobora gutuma habaho ibura ry’amazi n’ibiribwa. Abandi bo bahangayikishijwe n’ingaruka zishobora guterwa n’ihungabana ry’ubukungu. Bite se ku birebana n’impanuka kamere, ibyorezo by’indwara cyangwa ibitwaro bya kirimbuzi? Ese ibyo byo ntibishobora guteza imperuka y’isi?

Reka dusuzume muri make bimwe mu bintu abantu bakunze kuvuga ko bishobora guteza imperuka. Nubwo ibyo bintu biramutse bibayeho bitarimbura abatuye isi bose, nta gushidikanya ko bishobora guhindura imibereho yacu muri iki gihe. Dore bimwe muri byo:

Mu mwaka wa 1991, ikirunga cya Pinatubo cyo muri Filipine cyararutse, gihitana abantu barenga 700, kandi abagera ku 100.000 basigara badafite aho bikinga. Ivu riturutse muri icyo kirunga ryaratumutse rihinduka igicu kinini cyane ku birometero 30 mu kirere, maze rigaruka ku isi ryangiza imyaka, risenya n’ibisenge by’amazu. Icyo kirunga hamwe n’ibindi bimeze nka cyo, bituma habaho imihindagurikire y’ikirere na nyuma y’imyaka myinshi bimaze kuruka.

Haramutse habayeho ibirunga biruka cyane kurusha ibindi, urugero nk’ibyarukaga mu bihe bya kera, byarukana ubukana bukubye incuro amagana ubw’ibirunga byose byabayeho mu mateka, kandi byakwangiza byinshi. Uretse ibyo byakwangiza ako kanya, imihindagurikire y’ikirere byateza ku isi, yatuma umusaruro uba muke, maze abantu bakicwa n’inzara.

“Ibirunga byangiza imyaka kandi bikica inyamaswa. Abantu batinya ko niharamuka habayeho ibirunga biruka cyane, bizatuma habaho imihindagurikire y’ikirere, maze ibinyabuzima bigacika ku isi.” ​—“National Geographic.”

Umunsi umwe mu gitondo cya kare mu mwaka wa 1908, hari umugabo wari wiyicariye ku ibaraza ry’iduka mu mudugudu wa Vanavara muri Siberiya, yumva ikintu kiraturitse maze kimuhubuza ku ntebe yari yicayeho. Yagize ubushyuhe bwinshi ku buryo yumvaga ishati ye igurumana. Nyamara icyo kintu cyari giturikiye mu birometero 60 uvuye aho yari yicaye. Icyo kintu cyari umubumbe muto ufite umurambararo wa metero 35, kandi upima toni zigera ku 100.000. Uwo mubumbe umaze kugera mu kirere cy’isi, ubushyuhe hamwe n’imbaraga wamanukanye byatumye uturika. Waturikanye imbaraga zifite ubukana bw’ibisasu 1.000 bingana n’icyatewe mu mugi wa Hiroshima, maze wangiza igice cy’ishyamba ryo muri Siberiya gifite ubuso bwa kilometero kare 2.000. Birumvikana ko haramutse haturitse umubumbe uruta uwo, wakwangiza byinshi, ugateza inkongi y’umuriro ikaze, ibyo bikaba byatuma ubushyuhe bwo ku isi bugabanuka cyane maze ibinyabuzima byinshi bigacika.

“Kuva kera, hari imibumbe mito na za nyakotsi byagiye biva mu kirere bikitura ku isi. Ibyo byagiye bigira ingaruka mu gihe cyahise, kandi ntibyarangiriye aho kuko izo ngaruka zizongera zikatugeraho. Igisigaye gusa ni ukumenya igihe bizabera.”​—Chris Palma, umwarimu wigisha iby’inyenyeri muri kaminuza ya leta ya Pennsylvanie muri Amerika.

Abahanga mu bya siyansi bemeza ko bimwe mu bituma ku isi haba imihindagurikire y’ikirere, harimo ubwiyongere bw’ubushyuhe, imvura n’izuba bikabije, ibitare bya barafu byo ku mpera z’isi bigenda birushaho gushonga, n’igabanuka ry’ibinyabuzima bimwe na bimwe by’ingenzi hamwe n’ibintu byo mu nyanja byenda kumera nk’amabuye. Hari abantu benshi bemeza ko imihindagurikire y’ikirere iterwa no gukoresha nyiramugengeri, peteroli na gazi, kuko iyo bikoreshejwe mu modoka no mu nganda, byohereza umwuka wa gazi karubonike nyinshi mu kirere. Icyakora ibyo bavuga biracyagibwaho impaka.

Hari impuguke zemeza ko uwo mwuka ari nk’agakingirizo kabuza ubushyuhe buvuye ku isi gukwirakwira mu kirere, ibyo bigatuma ubushyuhe bwiyongera. Kubera ko ibiti bikurura umwuka wa gazi karubonike, iyo bitemwe ari byinshi bituma habaho imihindagurikire y’ikirere.

“Abahanga mu bya siyansi benshi bemeza ko ubushyuhe buri ku isi nibukomeza kwiyongera n’umwuka wa gazi karubonike ntugabanywe, umubumbe w’isi uzakomeza gushyuha, bigatuma habaho imihindagurikire y’ikirere kandi amazi yo mu nyanja akivumbagatanya akarengera uturere dukikije inkombe dutuwe n’abantu benshi.”​—“A Mind for Tomorrow: Facts, Values, and the Future.”

Mu kinyejana cya 14, icyorezo cy’indwara ifata uruhu cyahitanye abantu bangana na kimwe cya gatatu cy’Abanyaburayi, mu gihe cy’imyaka ibiri gusa. Hagati y’umwaka wa 1918 n’uwa 1920, icyorezo cy’indwara y’ibicurane cyishe abantu barenga miriyoni 50. Kuba nta buryo bwihuse bwo gukora ingendo bwabagaho, ni byo byatumye izo ndwara zidakwirakwira. Icyakora haramutse hadutse icyorezo kimeze nk’ibyo, cyakwirakwira ku migabane yose y’isi mu buryo bwihuse, bitewe n’uko imigi isigaye ituwe cyane kandi abantu bakaba bakora ingendo mpuzamahanga bitabagoye.

Icyorezo nk’icyo kibayeho, nta waba agiteje. Ariko ubu abantu baragenda barushaho kugira impungenge bitewe n’intwaro zikoresha mikorobe zanduza indwara. Impuguke mu gukora izo ntwaro zemeza ko hagize abantu bake bamenya uko izo ntwaro zikorwa, bashobora kugura ibikoresho bakoresheje interineti, maze bakikorera izo ntwaro zoreka imbaga.

“Indwara zikomeje guteza akaga gakomeye. Ariko kandi, umuntu w’umugome aramutse abonye virusi zitera izo ndwara, akabona [mikorobe zitumva imiti] cyangwa se akazikorera muri laboratwari, twaba tugushije ishyano.”​—The Bipartisan WMD Terrorism Research Center.

Mu myaka irenga itanu ishize, abavumvu bo muri Amerika bagiye batakaza 30 ku ijana by’inzuki zabo, bitewe n’icyorezo cyo ku isi cyibasira amarumbo y’inzuki, maze zigatoroka imizinga yazo mu buryo butunguranye kandi budasobanutse. Inzuki ntizituzanira amafaranga gusa. Zibangurira ibihingwa harimo imizabibu, pome, soya n’ipamba. Mu by’ukuri, zidufatiye runini.

Ibyatsi bito cyane biba mu nyanja na byo bidufatiye runini. Bitabayeho amafi ntiyabaho. Turamutse tudafite iminyorogoto ngo ifashe umwuka kwinjira mu butaka, imyaka yarumba. Ibyo binyabuzima by’ingenzi biramutse bishize ku isi, ibyokurya byaba bike abantu bakicwa n’inzara, ibyo na byo bikaba byateza urugomo n’imyiryane. Guhumanya ikirere, kwiyongera kw’abaturage, kubyaza isi umusaruro ukabije, kwangiza amashyamba inyamaswa zibamo hamwe n’imihindagurikire y’ikirere, bigira uruhare runini mu gutuma inyamaswa zicika ku isi. Birashoboka ko izo nyamaswa zicika ku muvuduko wikubye incuro 1.000 kurusha uko zari gucika abantu batabigizemo uruhare.

“Buri mwaka amoko y’ibinyabuzima ari hagati ya 18.000 na 55.000 acika ku isi, bitewe n’ibikorwa by’abantu.”​—United Nations Development Program.

Igisasu kimwe cya kirimbuzi gishobora kurimbura umugi mu kanya gato; ibyo byagaragaye incuro ebyiri muri Kanama 1945. Icyo gisasu kiba gifite imbaraga nyinshi, kuko iyo gituritse kirimbura ibintu gikoresheje umwuka, umuyaga, ubushyuhe, umuriro n’imirase yacyo. Uretse n’ibyo, imirase yacyo ihumanya amazi n’ibiribwa. Intambara ikoreshwamo ibitwaro bya kirimbuzi ishobora gutumura amatoni n’amatoni y’ivumbi, rigatuma urumuri rw’izuba rutagera ku isi, maze ubushyuhe bukagabanuka cyane. Ibyo byatuma imyaka irumba n’ibimera bikangirika, maze abantu n’inyamaswa bikicwa n’inzara. Ku isi hari ibihugu icyenda bivuga ko bifite intwaro za kirimbuzi n’ibindi bike bivuga ko birimo bizikora. Nanone ibyihebe byifuza cyane kuzibona.

“Na n’ubu, akaga gakomeye kugarije abantu kurusha ikindi kintu cyose ni intwaro za kirimbuzi. . . . Ku isi hari ibitwaro bya kirimbuzi bigera ku 25.000. . . . Byatinda byatebuka, ibyihebe na byo bizatunga izo ntwaro.”​—Union of Concerned Scientists.