Despite being known for his smoking character, Davis quit smoking in the 1970s; when The X-Files started up, he was given a choice between herbal cigarettes and tobacco cigarettes. At first, he chose to use tobacco cigarettes, but switched to herbal because he was afraid of becoming addicted to them again. Davis used his notoriety on the show to assist the Canadian Cancer Society in its programs to combat smoking. In 2014, Davis donated his Investments that support fossil fuels to the David Suzuki Foundation in an effort to both ethically invest, and help fund work to fight climate change. Davis is a passionate advocate for action in response to climate change, believes it is a critical issue of our time and speaks on the subject often. Taking action on a personal level, Davis drives a Tesla powered by hydroelectricity.