Is your purple kush green? Not its floral tint, but its environmental hue? Actually, back up a second. Can you say with certainty that it's purple kush? Where was it grown? Indoor or outdoor? What fertilizers and pest controls were used?

A trapping of black market weed is that it's difficult to trace with much certainty the origin of your smoke and the practices that nurtured it from seedling to bowl. What's an environmentally conscious stoner to do?

The simplest answer? Grow your own. If you're worried about the massive carbon footprint of the marijuana industry, grow it outdoors. A 2012 study from energy expert Evan Mills indicated 1 percent of the nation's electricity is used to power marijuana grows — $6 billion in energy expenditures. That electricity use, combined with marijuana transportation, produces as much greenhouse gas pollution in one year as 3 million cars.

It's even more concentrated in California, where marijuana cultivation consumes 3 percent of the state's total electricity use. Not that outdoor marijuana is energy-free, by any stretch — Mills' study indicates lighting makes up only 32 percent of a grow's electricity use.

Alarmed? You're in the minority. Humboldt Patient Resource Center Director Mariellen Jurkovich says her customers don't ask much about the carbon footprint of the collective's marijuana.

That doesn't stop her from thinking about it, though. If nothing else, the business' overhead grows and shrinks with efficient energy use. She says the collective, which grows its own marijuana indoors in Arcata, works regularly with light manufacturers to maximize growing power while minimizing energy use.

More successful, Jurkovich says, has been the collective's attention to sewer and water use. She says the center's cultivation operation uses the same amount of water as an average four-person household, and that they put little waste down the sewer. "We don't really want to waste water because we put nutrients in it, and they're expensive."

Public works departments around the county regularly deal with potent sewer discharges from household grows, and handling nutrient-rich wastewater can be troublesome for municipal treatment plants.

Then there are the pesticides and chemical fertilizers that are often used in clandestine grows because they're cheaper and easier than eco-groovy growing methods.

The Werc Shop, a marijuana laboratory based in Pasadena, reports that 10 percent of the marijuana submitted to the lab by dispensaries tests positive for pesticides at EPA dose limit levels.

Jurkovich says her collective is careful not to use harmful pesticides, not only for the environment but for the patients, who they see on a regular basis. Growers who are funneling their product through black market distribution don't see the end user, a disconnect that Jurkovich speculates may lead to less healthy growing practices.

With no industry standards to adhere to, marijuana dispensaries are largely left to self-regulate. City oversight varies wildly throughout the state.

Some municipalities are trying to reduce marijuana's carbon footprint. Arcata residents voted for a high-electricity tax designed to discourage energy-sucking household grows. The Emerald Growers Association offers tips and activism to promote sustainable marijuana growing. The Humboldt Patient Resource Center has opened its books to Humboldt State University students who've tracked energy use associated with marijuana. "We're really interested in working with them," Jurkovich says. "We're always hoping that will give us ideas."

But perhaps the only thing that can affect change is you — the smoker. If people eschew weed of dubious origins in favor of ethically and environmentally grown bud, growers may get the hint.

Jurkovich puts it succinctly. "There's a money component that really impacts how plants are taken care of."