Duba wurin da ke ƙasa sannan ka amsa tambayar daga baya a cikin harshe ɗaya kamar yadda wurin yake:  Passage: A ƙarshen shekarun 1960, Mikhail Ivanovich Budyko ya yi aiki tare da samfuran sauƙin yanayi mai sau biyu don bincika tasirin kankara. Ya gano cewa amsar albedo na kankara ya haifar da madaidaiciyar madaidaiciya a cikin tsarin sauyin yanayi na Duniya. Da yawa dusar ƙanƙara da kankara, da yawa hasken rana yana sake komawa cikin sararin samaniya sabili da haka ƙasa mai sanyi tana girma kuma da yawa yana dusar ƙanƙara. Sauran binciken sun gano cewa gurɓataccen yanayi ko fashewar dutsen mai fitad da wuta na iya haifar da farawar zamanin kankara.A cikin shekarun 1980, Atsumu Ohmura, mai binciken ilimin ƙasa a Cibiyar Fasaha ta Tarayyar Switzerland, ya gano cewa hasken rana da ke buga farfajiyar Duniya ya ragu da fiye da 10% a cikin shekaru talatin da suka gabata. Abubuwan da ya gano sun yi kama da rikice-rikice game da dumamar yanayi <unk> yawan zafin jiki na duniya ya kasance yana ƙaruwa tun daga shekarun 70. Ƙarancin haske da ya isa duniya kamar yana nufin cewa ya kamata ya yi sanyi. Ba da daɗewa ba wasu suka biyo baya: Viivi Russak a cikin 1990 "Yanayin hasken rana, girgije da kuma tsabtace yanayi a cikin 'yan shekarun nan a Estonia", da Beate Liepert a cikin 1994 "Hasken rana a Jamus <unk> Hanyoyin da aka lura da su da kuma kimantawa game da abubuwan da ke haifar da su". An kuma lura da dimming a wurare a duk faɗin tsohuwar Tarayyar Soviet. Gerry Stanhill wanda yayi nazarin wadannan raguwa a duk duniya a cikin takardu da yawa ya kirkiro kalmar "duhu na duniya".Bincike mai zaman kansa a Isra'ila da Netherlands a ƙarshen 1980s ya nuna raguwar bayyanar da hasken rana, duk da shaidar da aka samu cewa yanayin yana ƙara zafi. Adadin dimming ya bambanta a duk faɗin duniya amma a matsakaita an kiyasta kusan 2 <unk> 3% a kowace shekaru goma. Yanayin ya canza a farkon shekarun 1990.  Tambaya: Yaushe Liepert ya lura da irin wannan yanayin?
Shekarar 1994