National Marijuana Day: Not as green as you might think

Wednesday is National Pot Smokers Day, or National Marijuana Day, observed each April 20 and derived from the preferred time of consumption in the marijuana-smoking subculture — 4:20. A group of California Bay Area high school students, nicknamed the Waldos, is often credited with coining the term in the early 1970s.
Large public observances are planned in traditional hemp hotbeds San Francisco and Denver, but also in New York, and perhaps the largest is expected in Washington, according to High Times magazine.

Revelers might be alarmed to hear of a report this month that claims marijuana growth is not so environmentally friendly.

Evan Mills, a researcher at Lawrence Berkeley National Laboratory who said he did the work on his own time and without federal money, calculates the annual energy cost of indoor marijuana production at $5 billion annually, with associated greenhouse emissions equivalent to that of 3 million average automobiles. Mills' report said those costs are higher in areas where marijuana growth is legal.