Because it's not, you know - it's a fruit. However, In the US Supreme Court case, Nix v. Hedden, for purposes of classifying the item under the Tariff Act of 1883, the Court declared it to be a vegetable - nature be damned - so it could be taxed. No surprise there - the Court was bound to come down on the side of the government needing its revenue.
The Environmental Protection Agency's decision to classify rising carbon-dioxide emissions as a hazard to human health is the latest twist in a debate that has raged for decades among politicians, scientists and industry: whether a natural component of the earth's atmosphere should be considered a pollutant.
The EPA's finding doesn't say carbon dioxide, or CO2, is by itself a pollutant -- it is, after all, a gas that humans exhale and plants inhale. Rather, it is the increasing concentrations of the gas that concern the agency.However, the EPA ruled that today's higher concentrations are the "unambiguous result of human emissions." Concentrations of carbon dioxide and other gases "are well above the natural range of atmospheric concentrations compared to the last 650,000 years," the agency said.Carbon-dioxide levels in the Earth's atmosphere have fluctuated wildly for millennia; at one point billions of years ago, it was the dominant gas in the atmosphere.