Kammala wannan jumla: A yanzu ana tunanin cewa ɓarnawar ta faru ne saboda fashewar dutsen mai aman wuta na Dutsen Tambora a tsibirin Sumbawa, Indonesia a ranar 5 ga Afrilu 1815. Fashewar tana da darajar fashewar dutsen mai aman wuta (VEI) na 7, babban abin da ya faru wanda ya fitar da akalla kayan abu. Ya kasance mafi girman fashewar dutsen mai fitad da wuta a duniya a lokacin tarihi, kwatankwacin fashewar Minoan a karni na 2 kafin haihuwar Yesu, fashewar Hatepe na Tafkin Taupo a kusan 180 AD, fashewar Dutsen Paektu a 946 AD, da kuma fashewar
1257 fashewar Dutsen Samalas.