Yes, if not extinguished properly cigarette butts can lead to a range of negative environmental impacts, one of the worst being a bush fire which contributes to air pollution and respiratory disease. The embers of an improperly extinguished cigarette can smoulder for a prolonged period so if discarded improperly out a car window, cigarette butts have been know to cause bush fires.   The global issue of worsening bushfire frequencies is reflected in Australia, with the heightened risk caused by climate change worldwide.