Rashin sanyaya na duniya

Zubar da hankali a Duniya wani zato ne, musamman a cikin shekarun 1970s, na sanyaya mai zuwa na Duniya wanda ya ƙare a cikin wani lokaci mai zurfi, saboda tasirin sanyaya na aerosols ko tilastawar orbital. Wasu rahotanni na manema labarai a cikin shekarun 1970 sun yi hasashe game da ci gaba da sanyaya; waɗannan ba su nuna ainihin wallafe-wallafen kimiyya na lokacin ba, wanda gabaɗaya ya fi damuwa da dumama daga ingantaccen tasirin greenhouse.

A tsakiyar  shekarun 1970s, iyakantaccen jerin yanayin zafin da ake samu sun nuna cewa zafin jiki ya ragu shekaru da yawa har zuwa lokacin. Yayin da jerin lokaci mafi girma na inganci ya kasance, ya bayyana a fili cewa zafin jiki na duniya ya nuna karuwar girma gaba ɗaya. [ana yanayi hujja] [citation need]

## Gabatarwa: wayar da kan jama'a da damuwa
A cikin shekarun 1970s, masana kimiyya sun kara fahimtar cewa kimantawa na yanayin zafi na duniya ya nuna sanyaya tun 1945, da kuma yiwuwar babban zafin jiki saboda fitar da iskar gas. A cikin takardun kimiyya waɗanda suka yi la'akari da yanayin yanayi na karni na 21, ƙasa da kashi 10% sun karkata zuwa sanyaya nan gaba, yayin da yawancin takardun suka yi hasashen dumama nan gaba. Jama'a ba su da masaniya game da tasirin carbon dioxide akan yanayi, amma *Labaran Kimiyya* a watan Mayu, shekara ta 1959 ya yi hasashen karuwar kashi 25% a cikin carbon dioxide na yanayi a cikin shekaru 150 daga shekara ta 1850 zuwa shekarar 2000, tare da yanayin dumama. Ainihin karuwa a wannan lokacin ya kasance 29%. Paul R. Ehrlich ya ambaci dumamar duniya daga iskar gas a matsayin mai hanawa ga tasirin sanyaya na aerosols a shekarar 1968. A lokacin da ra'ayin sanyaya duniya ya kai ga manema labarai a tsakiyar shekarun 1970 yanayin zafi ya daina faduwa, kuma akwai damuwa a cikin al'ummar yanayin yanayi game da tasirin zafi na carbon dioxide. A mayar da martani ga irin waɗannan rahotanni, Hukumar Kula da Yanayi ta Duniya ta ba da gargadi a watan Yunin Shekarar 1976 cewa "wani gagarumin zafi na yanayi na duniya" mai yiwuwa ne.

A halin yanzu, akwai wasu damuwa game da yiwuwar tasirin sanyaya na yanki na raguwa ko rufewar yaduwar thermohaline, wanda zai iya haifar da karuwar Ruwa mai kyau da ke haɗuwa a cikin Arewacin Atlantic saboda narkewar glacial. Ana ganin yiwuwar wannan ya faru a matsayin ƙasa sosai, kuma IPCC ya lura, "ko da a cikin samfuran inda THC ke raunana, har yanzu akwai dumi a Turai. Misali, a duk haɗin AOGCM inda tilasta radiative ke ƙaruwa, alamar canjin zafin jiki a arewa maso yammacin Turai tana da kyau. "

## Hanyoyin jiki
Lokacin sanyaya yana sakewa ta hanyar Tsarin yanayi na duniya na yanzu (a shekara ta 1999 a kan) wanda ya haɗa da tasirin jiki na aerosol" id="mwUg" rel="mw:WikiLink" title="Sulfate aerosols">Sulfate aerosols, kuma yanzu akwai yarjejeniya ta gaba ɗaya cewa tasirin aerosol shine babban dalilin sanyaya na tsakiyar karni na 20. A lokacin akwai hanyoyin jiki guda biyu waɗanda aka fi ci gaba da su akai-akai don haifar da sanyaya: aerosols da tilasta orbital.

### Aerosols
Ayyukan ɗan adam - galibi a matsayin samfur na konewa man fetur, wani ɓangare ta hanyar canje-canje na Amfani da ƙasa - yana ƙara yawan ƙananan barbashi (aerosols) a cikin yanayi. Wadannan suna da tasiri kai tsaye: suna kara yawan albedo na duniya, don haka suna sanyaya duniya ta hanyar rage Hasken rana da ya kai saman; da kuma sakamako na kai tsaye: sun shafi kaddarorin girgije ta hanyar aiki a matsayin ƙwayoyin girgije. A farkon shekarun 1970 wasu sun yi hasashen cewa wannan tasirin sanyaya na iya mamaye tasirin dumama na sakin CO<sub>2</sub>: duba tattaunawar Rasool da Schneider (a shekarar 1971), a ƙasa. A sakamakon lura da sauyawa zuwa ƙone mai tsabta, wannan ba zai yiwu ba; aikin kimiyya na yanzu yana nuna cewa dumamar duniya ya fi dacewa. Kodayake raguwar zafin jiki da wannan tsarin ya hango yanzu an watsar da shi saboda mafi kyawun ka'idar da kuma yanayin zafi da aka lura, ana zaton aerosols sun ba da gudummawa ga yanayin sanyaya (wanda ya fi nauyi da karuwar iskar gas) kuma sun ba da damar dimming na duniya.

### Matsi na Orbital

Orbital tilasta yana nufin jinkirin, canje-canje na cyclical a cikin karkatawar axis na Duniya da kuma siffar ta orbit. Wadannan sake zagayowar suna canza jimlar hasken rana da ke isa Duniya da karamin adadi kuma suna shafar lokaci da tsananin yanayi. Wannan hanyar ana zaton tana da alhakin lokacin sake zagayowar zamanin kankara, kuma fahimtar hanyar tana ƙaruwa cikin sauri a tsakiyar shekarun 1970.

Takardar Hays, Imbrie, da Shackleton "Variations in the Earth's Orbit: Pacemaker of the Ice Ages" sun cancanci tsinkayinsu tare da tsokaci cewa "dole ne a cancanta a hanyoyi biyu. Na farko, suna amfani ne kawai ga ɓangaren halitta na yanayin yanayi na gaba - kuma ba ga Tasirin ɗan adam kamar waɗanda suka faru saboda ƙone burbushin burbushin halittu ba. Na biyu, suna bayyana yanayin dogon lokaci ba ne kawai, saboda yanayin yanayin yanayin yanayin Arewa-lokaci na gaba ba.&nbsp;

Ra'ayin cewa za'a iya hango yanayin shekarun kankara da ra'ayin cewa wani ya kasance saboda "ba da daɗewa ba" - watakila saboda yawancin wannan binciken ya faru ne daga masana kimiyyar ƙasa, waɗanda suka saba da magance ma'auni na dogon lokaci kuma suna amfani da "ba da sauri" don komawa ga lokutan dubban shekaru. Aikace-aikacen ka'idar Milankovitch ba ya ba da damar tsinkaya na farkon shekarun kankara "mai sauri" (watau, ƙasa da ƙarni ɗaya ko biyu) tunda lokacin da ya fi sauri shine kimanin shekaru 20,000. An sami wasu hanyoyi masu ban sha'awa game da wannan, musamman wanda Nigel Calder ya goyi bayan a ƙarƙashin sunan "snowblitz", amma waɗannan ra'ayoyin ba su sami karɓa mai yawa ba.

Tsawon yawan zafin jiki na yanzu yayi kama da tsawon saman Interglacial da ya gabata (Sangamon / Eem), don haka ana iya kammala cewa muna iya kusantar ƙarshen wannan lokacin zafi. Wannan ƙaddamarwa za ta yi kuskure. Da farko, saboda tsawon interglacials na baya ba na yau da kullun ba ne;  duba adadi. Petit et al. sun lura cewa "interglacials 5.5 da 9.3 sun bambanta da Holocene, amma suna kama da juna a tsawon lokaci, siffar da faɗin. A lokacin kowane ɗayan waɗannan abubuwan biyu, akwai lokacin dumi na 4 kyr wanda ya biyo bayan sanyaya mai sauri". Abu na biyu, bambance-bambance na gaba ba za su yi kama da na baya ba.

## Damuwa kafin shekarun 1970
A cikin shekarar 1923, akwai damuwa game da sabon zamanin kankara kuma Kyaftin Donald Baxter MacMillan ya tashi zuwa Arctic wanda National Geographical Society ta tallafawa don neman shaidar ci gaba da kankara.

A cikin shekara ta 1926, wani masanin taurari na Berlin yana hasashen sanyaya duniya amma cewa "tsufa ne".

An farfado da damuwa cewa sabon zamanin kankara yana gabatowa a cikin shekarun 1950. A lokacin Yaƙin Cold, Harry Wexler ya damu da cewa kashe bama-bamai na atom na iya hanzarta sabon zamanin kankara daga yanayin hunturu na nukiliya.

J. Murray Mitchell ya nuna tun farkon shekarar 1963 sanyaya mai shekaru da yawa tun daga kimanin shekara ta 1940.  A wani taro kan canjin yanayi da aka gudanar a Boulder, Colorado a shekarar 1965, shaidar da ke tallafawa sake zagayowar Milankovitch ta haifar da hasashe kan yadda aka lissafa ƙananan canje-canje a hasken rana na iya haifar da shekarun kankara. A cikin shekarata 1966, Cesare Emiliani ya yi hasashen cewa "sabon ƙanƙara zai fara cikin 'yan dubban shekaru. " A cikin littafinsa na shekarata 1968 The Population Bomb, Paul R. Ehrlich ya rubuta "Sakamako na greenhouse yana ingantawa yanzu ta hanyar karuwar matakin carbon dioxide ... [wannan] ana magance shi da girgije mai ƙarancin matakin da aka samar da ƙura, ƙura, da sauran gurɓata ... A halin yanzu ba za mu iya hango abin da sakamakon yanayi zai kasance na amfani da yanayinmu a matsayin shara ba. "&nbsp;&nbsp;

## Damuwa a cikin shekarun 1970
 
Damuwa ta kai kololuwa a farkon shekarun 1970s, kodayake " yiwuwar dumama ta mutum ta mamaye wallafe-wallafen da aka sake dubawa har ma a lokacin"  (lokacin sanyaya ya fara a shekarar 1945, kuma shekaru ashirin na yanayin sanyaya ya nuna cewa an kai ga rami bayan shekaru da yawa na dumama). Wannan damuwa mai yawa ya kasance a wani bangare saboda gaskiyar cewa ba a san shi sosai ba game da yanayin duniya da abubuwan da ke haifar da shekarun kankara. Masana kimiyya na yanayi sun san cewa tsinkaya bisa ga wannan yanayin ba zai yiwu ba - saboda ba a yi nazarin yanayin sosai ba kuma ba a fahimta ba (alal misali duba nassi ). Duk da haka, a cikin shahararrun manema labarai an bayar da rahoton yiwuwar sanyaya gabaɗaya ba tare da gargadi da ke cikin rahotanni na kimiyya ba, kuma "ƙananan hunturu a Asiya da sassa na Arewacin Amurka a cikin Shekara ta 1972 da Shekarar 1973 ... sun tura batun cikin sanin jama'a".&nbsp;

A cikin shekarun 1970s, tattara bayanan don samar da bayanan hemispheric, ko na duniya, sun fara.

Tarihin Spencer R. Weart na The Discovery of Global Warming ya ce: "Yayin da ba masana kimiyya ko jama'a ba za su iya tabbatarwa a cikin shekarun 1970s ko duniya tana da zafi ko sanyaya, mutane sun kara karkata suyi imani cewa yanayin duniya yana kan tafiya, kuma a kowace hanya ba" [an kara da hankali].

A ranar 11 ga watan Janairun shekara ta 1970, The Washington Post ta ruwaito cewa "Colder Winters Held Dawn of New Ice Age".

A shekara ta 1972, Emiliani ya yi gargadi cewa "Ayyukan Mutum na iya haifar da wannan sabon zamanin kankara ko kuma haifar da narkewar kankara".

Har ila yau, a cikin shekarata 1972, wani rukuni na masana na lokacin glacial a wani taro sun amince da cewa "ƙarshen yanayi na zamaninmu mai dumi tabbas yana kusa";  amma ƙarar Quaternary Research da ke bayar da rahoto game da taron ya ce "mahimmanci da za a samu daga tattaunawar a wannan sashe shi ne cewa ilimin da ake buƙata don fahimtar tsarin canjin yanayi har yanzu bai isa ba". George Kukla da Robert Matthews, a cikin rubuce-rubucen *Kimiyya* na wani taro, sun tambayi lokacin da kuma yadda interglacial na yanzu zai ƙare; sun kammala cewa, sai dai idan akwai tasiri daga ayyukan ɗan adam na gaba, "Zamara ta duniya da canje-canje masu sauri na muhalli, wanda ya wuce sauye-sauyen da mutum ya samu a lokutan tarihi, dole ne a cikin 'yan dubban shekaru ko ma ƙarni masu zuwa",  amma wasu masana kimiyya da yawa sun yi shakkar waɗannan ƙaddamarwa.

### Rahoton SCEP na Shekarar 1970
Nazarin shekara ta 1970 na Matsalolin Muhalli masu Muhimmanci  ya ba da rahoton yiwuwar dumama daga karuwar carbon dioxide, amma babu damuwa game da sanyaya, yana saita ƙananan iyaka a farkon sha'awa a cikin "sanyi na duniya".

### A Shekara ta 1971 zuwa shekarar 1975: takardu kan abubuwan dumi da sanyaya
A shekara ta 1971, bincike ya nuna cewa dan Adam ya haifar da gurɓataccen iska yana yaduwa, amma akwai rashin tabbas game da ko iska zai haifar da dumama ko sanyaya, kuma ko sun fi girma CO2 matakan. J. Murray Mitchell har yanzu yana kallon mutane a matsayin "masu kallo marasa laifi" a cikin sanyi daga 1940s zuwa 1970, amma a cikin 1971 lissafinsa ya nuna cewa tashin hayaki zai iya haifar da sanyi mai mahimmanci bayan 2000, ko da yake ya kuma yi jayayya cewa hayaki na iya haifar da dumamar yanayi. Lissafi sun yi yawa na asali a wannan lokacin don a amince da su don ba da ingantaccen sakamako.      

An buga ƙididdigar ƙididdiga ta farko game da tasirin yanayi a cikin mujallar Science a watan Yulin shekarar 1971 a matsayin takarda ta S. Ichtiaque Rasool da Stephen H. Schneider, mai taken "Atmospheric Carbon Dioxide and Aerosols: Tasirin Babban Karin Yanayi akan Yanayin Duniya". Takardar ta yi amfani da bayanai da daidaitattun bayanai don lissafin yiwuwar tasirin gaba na karuwa mai yawa a cikin yanayin nau'ikan hayakin muhalli guda biyu: 

# iskar gas kamar carbon dioxide;
# gurɓataccen ƙwayoyin kamar su smog, wasu daga cikinsu sun kasance an dakatar da su a cikin yanayi a cikin nau'in aerosol na shekaru.

Takardar ta ba da shawarar cewa dumamar duniya saboda iskar gas zai kasance da ƙarancin tasiri tare da yawa, kuma yayin da gurɓataccen aerosol na iya haifar da dumama, mai yiwuwa zai sami tasirin sanyaya wanda ya karu da yawa. Sun kammala cewa "Ƙaruwar kashi 4 kawai a cikin maida hankali na duniya na iya isa ya rage yawan zafin jiki na ƙasa da kusan 3.5 ° K. Idan an ci gaba a cikin shekaru da yawa, irin wannan raguwar zafin jiki a duk duniya an yi imanin ya isa ya haifar da zamanin kankara. "

Dukkanin ma'aunin su da bayanan su sun kasance da mummunar kuskure, kamar yadda wasu masana kimiyya suka nuna kuma Schneider da kansa ya tabbatar.CO="true" id="mwATM" typeof="mw:Transclusion">CO=\"true\" id=\"mwA58\">nbsp;. American Institute of Physics. Archived from  on June 29, 2016 2012."}}' id="cite_ref-Weart_aerosols_27-1" rel="dc:references" typeof="mw:Extension/ref">[1] A watan Janairun Shekarar1972, Robert Jay Charlson et al. sun nuna cewa tare da wasu zato masu ma'ana, samfurin ya samar da akasin haka. Misali bai ba da izini ga canje-canje a cikin girgije ko convection ba, kuma ya nuna cewa sau takwas fiye da CO2 zai haifar da 2 ° C na dumama. A cikin wata takarda da aka buga a shekarar 1975, Schneider ya gyara ƙididdigar sanyaya ta hanyar bincika bayanai game da tasirin ƙurar da dutsen wuta ya samar. Lokacin da samfurin ya haɗa da kimanta canje-canje a cikin ƙarfin hasken rana, ya ba da daidaituwa mai ma'ana ga yanayin zafi a cikin shekaru dubu da suka gabata kuma tsinkayar sa ita ce "CO2 warming ya mamaye yanayin zafin jiki ba da daɗewa ba bayan shekara ta 1980. "&nbsp;

### Hukumar Kimiyya ta Kasa a shekara ta 1972 da shekarar 1974
Rahoton Hukumar Kimiyya ta Kasa da Perspectives a cikin Kimiyyar Muhalli na 1972 sun tattauna game da halayyar yanayi, da kuma fahimtar lokacin da duniyar ke shiga wani lokaci na sanyaya bayan lokacin dumi. "A yin hukunci daga rikodin shekarun interglacial da suka gabata, lokacin yanzu na yanayin zafi ya kamata ya ƙare, don a bi shi da dogon lokaci na yanayin sanyi mai yawa wanda ke haifar da zamanin glacial na gaba kimanin shekaru 20,000 daga yanzu. "  Amma kuma ya ci gaba; "Duk da haka, yana yiwuwa, ko ma mai yiwuwa, cewa tsangwama na ɗan adam ya riga ya canza yanayin yanayi sosai cewa yanayin yanayi na nan gaba zai bi wata hanya daban. "

Rahoton kwamitin na shekarar 1974, Science And The Challenges Ahead, ya ci gaba da wannan taken. "A cikin shekaru 20-30 da suka gabata, zafin jiki na duniya ya fadi, ba bisa ka'ida ba a farkon amma mafi tsananin a cikin shekaru goma da suka gabata. "  Tattaunawa game da lokutan glacial na cyclic ba ya cikin wannan rahoto. Maimakon haka, rawar da mutane ke takawa ne wanda ke da mahimmanci ga nazarin rahoton. "Ba a san dalilin yanayin sanyaya da tabbaci ba. Amma akwai damuwa mai yawa cewa mutum da kansa na iya shiga, ba kawai a cikin yanayin sanyaya na baya-bayan nan ba har ma da yanayin zafi a cikin karni na ƙarshe".  Rahoton bai kammala ko carbon dioxide a cikin dumama ba, ko gurɓataccen aikin gona da masana'antu a cikin sanyaya, dalilai ne a cikin canje-canjen yanayi na baya-bayan nan, yana mai lura; "Kafin a warware irin waɗannan tambayoyin, dole ne a sami manyan ci gaba wajen fahimtar sunadarai da kimiyyar lissafi na yanayi da Tekuna, da kuma auna da bin diddigin ƙwayoyin ta hanyar tsarin".

### Rahoton Kwalejin Kimiyya ta Kasa na shekarar 1975
Har ila yau, akwai wani rahoto daga Kwalejin Kimiyya ta Amurka (NAS) mai taken, "Ganin Canjin Yanayi: Shirin Aiki".

Rahoton ya bayyana (shafi na 36) cewa, "Matsakaicin yanayin zafi na iska a arewacin arewa ya karu daga 1880s har zuwa kimanin Shekara 1940 kuma yana raguwa daga baya".&nbsp;

Ya kuma bayyana (shafi na 44) cewa, "Idan duka  da abubuwan da ke cikin yanayi sun karu da daidaito a nan gaba, bambancin lokutan zama na yanayi na gurbataccen abu biyu yana nufin cewa tasirin barbashi zai karu da muhimmancin da ya danganta da na CO2. "&nbsp;

Rahoton bai yi hasashen ko yanayin sanyaya na shekaru 25 zai ci gaba ba. Ya bayyana (Forward, p. v) cewa, "ba mu da kyakkyawar fahimtar ma'auni game da na'urarmu ta yanayi da abin da ke ƙayyade hanyarsa [don haka] ba zai yiwu a hango yanayin ba", kuma (shafi na 2) "Yanayin duniya koyaushe yana canzawa, kuma tabbas za su ci gaba da yin hakan a nan gaba. Yaya manyan waɗannan canje-canje na gaba za su kasance, kuma inda kuma yadda za su faru da sauri, ba mu sani ba".[so]&nbsp;

Rahoton "shirin aiki" kira ne don ƙirƙirar sabon Shirin Binciken Yanayi na Kasa. Ya bayyana (shafi na 62), "Idan za mu amsa da hankali ga canje-canjen yanayi na gaba, kuma idan za mu taɓa yin hasashen hanyarsu ta gaba, ko na halitta ne ko na mutum, ana buƙatar fahimtar waɗannan canje-cancen fiye da yadda muke da su yanzu. Yana da mahimmanci cewa a sami wannan ilimin da wuri-wuri. " Saboda wannan dalili, ya ce, "Lokacin yanzu ya zo don fara kai farmaki mai zurfi da daidaitawa kan matsalar yanayi da canjin yanayi".&nbsp;

### Labarin mujallar Time a shekarar 1974
Duk da yake waɗannan tattaunawar suna ci gaba a cikin masana kimiyya, wasu asusun sun bayyana a cikin shahararrun kafofin watsa labarai. A cikin fitowarsu ta 24 ga  watan Yuni, shekara ta 1974, Time ta gabatar da wata kasida mai taken "Another Ice Age?" wanda ya lura cewa "yanayin yana karuwa a hankali a cikin shekaru talatin da suka gabata" amma ya lura cewa ""Wasu masana kimiyya ... suna tunanin cewa yanayin sanyaya na iya zama na wucin gadi kawai" &nbsp;

### Labarin Labaran shekarar 1975
Wani labarin Afrilu  28 ga wata, Shekara ta 1975, a cikin mujallar Newsweek mai taken "Duniya mai sanyi", [1] ta yi nuni da "alamomi masu ban tsoro cewa yanayin duniya ya fara canzawa" kuma ya nuna "digo na rabin digiri [Fahrenheit] a matsakaicin yanayin zafi na ƙasa a Arewacin Hemisphere tsakanin shekara ta 1945 da shekarar  1968." Labarin ya ce "Shaidun da ke nuna goyon bayan waɗannan hasashen [na sanyin duniya] yanzu sun fara taruwa sosai har masana yanayi suna da wahala su ci gaba da kasancewa tare da shi." Labarin Newsweek bai bayyana dalilin sanyaya ba; ya bayyana cewa "abin da ke haifar da farkon manyan shekarun kankara da kankara ya kasance a asirce" kuma ya kawo karshen NAS cewa "ba wai kawai tambayoyin kimiyya na asali ba ne kawai ba a amsa ba, amma a lokuta da yawa har yanzu ba mu san isa don gabatar da muhimman tambayoyin ba."

Labarin ya ambaci madadin mafita na "melting Arctic ice cap ta hanyar rufe shi da baki soot ko karkatar da koguna na Arctic" amma ya yarda cewa waɗannan ba su yiwu ba. Labarin *Newsweek* ya kammala ta hanyar sukar shugabannin gwamnati: "Amma masana kimiyya sun ga alamun da yawa cewa shugabannin gwamnati a ko'ina sun shirya don ɗaukar matakai masu sauƙi na adana abinci ko gabatar da sauye-sauye na rashin tabbas na yanayi a cikin tsinkayen tattalin arziki na kayan abinci na gaba ... Yayin da masu tsarawa (yan siyasa) suka jinkirta, mafi wuya za su sami shi don magance canjin yanayi da zarar sakamakon ya zama mummunan abu. Labarin ya jaddada da yawa - "yawarwar yunwa na duniya", "ya mai yawa ya haifar da kullun"&nbsp;

A ranar 23 ga watan Oktoba, shekara ta 2006, *Newsweek* ta ba da gyare-gyare, sama da shekaru 31 bayan labarin na asali, yana mai cewa "ba daidai ba ne game da makomar nan gaba" (ko da yake editan Jerry Adler ya bayyana cewa "labarin ba 'ba daidai ba' a cikin ma'anar jarida na 'ba daidai bane.'") 

### Sauran tushe na shekarun 1970
Binciken ilimi na binciken da aka buga a wannan lokacin ya nuna cewa yawancin takardu da ke nazarin bangarorin yanayi a cikin shekarun 1970 sun kasance tsaka-tsaki ko kuma sun nuna yanayin dumama.

A shekara ta 1977, an buga wani sanannen littafi game da batun, mai suna The Weather Conspiracy: The Coming of the New Ice Age . 

### Taron WMO na Shekarar 1979
Daga baya a cikin shekaru goma, a taron WMO a 1979, F. Kenneth Hare ya ruwaito:

## Tsinkaya na sanyaya na ƙarshen ƙarni na 20

### Shekarun 1980
Damuwa game da hunturu na nukiliya ya tashi a farkon shekarun 1980 daga rahotanni da yawa. Irin wannan hasashe ya bayyana a kan tasirin saboda bala'o'i kamar tasirin asteroid da manyan fashewar dutse.

### Shekarun 1990
A cikin Shekara ta 1991, tsinkaya da Carl Sagan da sauran masana kimiyya da suka yi aiki a kan sanannen binciken TTAPS akan hunturu na nukiliya cewa Babban gobarar rijiyar mai a Kuwait za ta haifar da tasiri mai mahimmanci akan yanayi ba daidai ba ne.

A watan Janairun shekarar 1999, mai adawa Patrick Michaels ya rubuta wani sharhi don "karɓar kuɗi cewa shekaru 10 da suka ƙare a ranar 31 ga watan Disamba, shekara ta 2007, za su nuna wani yanayi mai mahimmanci na sanyaya duniya a cikin yanayin da aka auna ta hanyar tauraron dan adam", bisa ga ra'ayinsa cewa yanayin rikodin a cikin a shekarar 1998 ya kasance blip. Lalle ne, a wannan lokacin, yanayin da aka auna na tauraron dan adam bai sake kusantar mafi girma na 1998 ba. Saboda raguwa mai zurfi amma na wucin gadi a cikin yanayin zafi a cikin Shekara ta 1999 da shekarar 2000, raguwar layi mafi ƙanƙanta da ya dace da rikodin zafin tauraron dan adam ya nuna ƙarancin yanayin gaba ɗaya. Rubuce-rubucen zafin tauraron dan adam na RSS ya nuna dan kadan, amma rikodin zafin taurarin dan adam na UAH ya nuna dan karamin yanayin zafi.

A shekara ta 2003, an ba da umurni ga Ofishin Binciken Net a Ma'aikatar Tsaro ta Amurka don samar da bincike kan yiwuwar tasirin canjin yanayi na zamani idan rufewar yaduwar thermohaline ya faru. Binciken, wanda aka gudanar a karkashin shugaban ONA Andrew Marshall, ya tsara canjin yanayi a kan taron kiloyear 8.2, daidai saboda shi ne madadin tsakiya tsakanin Younger Dryas da Little Ice Age. Masana kimiyya sun ce "canjin yanayi na kwatsam wanda ya fara ta hanyar narkewar kankara ta Greenland ba wani lamari ne na gaskiya ba na karni na 21".

## Matsayin ilimi na yanzu
Damuwa cewa yanayin sanyi zai ci gaba, kuma watakila a cikin sauri, an lura da shi ba daidai ba ne, kamar yadda aka tantance shi a cikin Rahoton Bincike na Uku na IPCC na Shekarar 2001. Dole ne a koyi ƙarin bayani game da yanayi. Koyaya, bayanan da ke ƙaruwa sun nuna cewa ba a tabbatar da damuwa game da sanyaya na ɗan gajeren lokaci ba.

..Amma game da abubuwan da ke faruwa na ƙarshen interglacial na yanzu, yayin da interglacials na baya-bayan nan huɗu sun kasance kusan shekaru 10,000, interglacial kafin hakan ya kasance kusan shekaru 28,000. Ƙididdigar nau'in Milankovitch yana nuna cewa mai yiwuwa interglacial na yanzu zai ci gaba har tsawon dubun dubatar shekaru a dabi'a idan babu matsalolin ɗan adam.[1] Wasu ƙididdiga (Loutre da Berger, bisa la'akari da lissafin orbital) sun sanya tsayin da ba a damu ba na interglacial na yanzu a shekaru 50,000.[2]. A. Berger ya bayyana ra'ayi a cikin 2005 (EGU gabatarwa) cewa halin yanzu CO2 perturbation zai šauki tsawon isa ya murkushe gaba glacial sake zagayowar gaba ɗaya. Wannan ya yi daidai da tsinkayar David Archer da abokan aiki waɗanda suka yi jayayya a cikin 2005 cewa matakin yanzu na CO2 zai dakatar da lokacin glacial na gaba don shekaru 500,000 na gaba kuma zai zama tsawon lokaci mafi tsawo da tsanani na lokacin interglacial da aka tsara kuma sun fi tsayi fiye da yadda aka gani a cikin shekaru miliyan 2.6 na ƙarshe.[3].

Wani rahoto na  da Cibiyar Canje-canje ta Duniya ta baya, gami da Berger, ya ce kwaikwayon ya nuna cewa sabon glaciation ba zai yiwu ya faru a cikin kimanin shekaru 50,000 masu zuwa ba, kafin raguwa mai karfi na gaba a cikin Insolation na Arewacin Hemisphere ya faru "idan ko dai maida hankali na ="true" id="mwAf0" typeof="mw:Transclusion">CO="true" id="mwAfs" typeof="mw:Transclusion">CO ya kasance sama da 300 ppm ko yawan hayakin carbon ya wuce 1000 Pg C" (watau 1000 gigatonnes carbon). "Kawai ga abun ciki na CO2 na yanayi a ƙasa da matakin preindustrial na iya faruwa a cikin 10 ka na gaba. ... Idan aka ba da ci gaba da fitar da CO2 na ɗan adam, farkon ƙanƙara ba zai yiwu ya faru a cikin 50 ka na gaba ba, saboda ma'auni na CO2 da raguwar zafin jiki zuwa ga ƙimar da ba a damu ba tare da cirewa mai aiki ba yana da tsawo sosai [IPCC, 2013], kuma rauni ne kawai na ƙarancin ƙarancin lokaci don motsa jiki na gaba. " (A precessional yana kusa da shekara mai zuwa ga duk zagaye na gaba).

Kamar yadda rahoton NAS ya nuna, ilimin kimiyya game da canjin yanayi ya fi tabbas fiye da yadda yake a yau. A lokacin da Rasool da Schneider suka rubuta takarda ta Shekarar 1971, masu ilimin yanayi ba su riga sun fahimci muhimmancin iskar gas ba banda tururin ruwa da carbon dioxide, kamar methane, nitrous oxide, da chlorofluorocarbons. A farkon wannan shekaru goma, carbon dioxide shine kawai iskar gas mai tasiri ta mutum. Halin da aka jawo ga iskar gas a cikin shekarun 1970s ya haifar da abubuwan da aka gano da yawa a cikin shekarun da suka biyo baya. Yayinda yanayin zafin jiki ya canza, sanyaya na duniya ya ragu a shekara ta 1979.

## Ƙaryacewar zamanin kankara
Wata hujja ta yau da kullun da aka yi amfani da ita don watsar da muhimmancin canjin yanayi da mutum ya haifar shine ya yi zargin cewa masana kimiyya sun nuna damuwa game da sanyaya duniya wanda bai faru ba, sabili da haka babu buƙatar kula da damuwar kimiyya na yanzu game da dumamar duniya. A cikin wata kasida ta Shekarar 1998 da ke inganta Oregon Petition, Fred Singer ya yi jayayya cewa ya kamata a watsar da damuwa game da dumamar duniya bisa ga abin da ya kira "tsoron tashin hankali iri ɗaya" an bayyana shi a baya game da sanyaya duniya.

Bryan Walsh na mujallar Time (a shekarar 2013) ya kira wannan gardamar "Fallacy na Ice Age". Da yake kwatanta gardamar, shekaru da yawa an rarraba hoton murfin *[[Time (magazine)|Lokaci]]*, wanda ake zaton kwanan wata a shekarar 1977, yana nuna penguin sama da taken labarin murfin "Yadda za a tsira da Zamanin Ice mai zuwa". A watan Maris na shekara ta 2013, The Mail on Sunday ya buga wata kasida ta David Rose, tana nuna wannan hoton murfin, don tallafawa da'awarsa cewa akwai damuwa da yawa a cikin shekarun 1970s game da "*Lokaci* 'ƙanƙara' kamar yadda yake yanzu game da dumamar duniya. Bayan bincike kan sahihancin hoton murfin mujallar, a watan Yulin 2013, Walsh ya tabbatar da cewa hoton yaudara ne, an gyara shi daga hoton labarin murfin a shekarar 2007 don "The Global Warming Survival Guide".

## Dubi kuma
 

## Manazarta

## Ƙarin karantawa

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* http://tvnews.vanderbilt.edu/program.pl? ID=52903 Vanderbilt Television News Archive
* 

## Haɗin waje

* Menene masana kimiyyar yanayi da suka yi hasashen a cikin shekarun 1970s? , taƙaitaccen bayani ga masu bincike da ka'idojin makirci ta hanyar Skeptical Science, wanda masanin ilimin halittu na ruwa Ove Hoegh-Guldberg ya bayyana "mafi shahararren gidan yanar gizon da ke da alaƙa da canjin yanayi a duniya".
* Tattaunawa da kalaman daga takardu daban-daban game da "1970s tsinkaya na zamanin kankara mai zuwa", by Wm Connolley
* SCOPE.org/downloadpubs/scope13/foreword.html" id="mwBTk" rel="mw:ExtLink nofollow">SCOPE 13 - Tsarin Carbon na Duniya, SCOPE, 1976.
* SCOPE 27 - Binciken Tasirin Yanayi, 1984.
*  
* 
* Canjin Yanayi na baya - wasu takardun jarida
* Nazarin Binciken Yanayi kamar yadda ya shafi Matsalolin Lantarki - rahoton CIA daga 1974
* Tasirin geohydrological na canjin yanayi akan ci gaban albarkatun ruwa, C. W. Stockton da W. R. Boggess, Rahoton Kwangilar DACW 72-78-C-0031, don Cibiyar Injiniyan Ruwa ta Amurka, Fort Belvoir, Virginia, C.  (Dubi shafi na 159) &nbsp;