The total contribution of carbon dioxide and other greenhouse gases by a particular activity, enterprise, or product. The increasing concern about the harmful effect of human activity on the environment has promoted the use of this term, which may soon be a cliché. The Boston Globe travel section headlined an article on “green” (ecologically harmless) vacations: “Leave Your Carbon Footprint at Home” (June 6, 2010). Gregg Hurwitz’s novel They’re Watching (2010) has the lines, “‘What’s a lifestyle coach do, exactly?’ I asked. ‘We’re working on reducing Keith’s carbon footprint.’”