People growing marijuana indoors use 1 percent of the U.S. electricity supply, and they create 17 million metric tons of carbon dioxide every year (not counting the smoke exhaled) according to a report by Evan Mills, an energy analyst at Lawrence Berkeley National Laboratory.
After medical pot use was made legal in California in 1996, Mills says, per-person residential electricity use in Humboldt County jumped 50 percent compared to other parts of the state.
Full Story: Marijuana causes global warming, uses 1% of U.S. electricity | San Francisco Business Times