Across the country, there’s a growing trend toward the legalization of marijuana. Four states — Oregon, Washington, Colorado, Alaska — have voted to allow people to possess limited amounts of marijuana for personal use and also to let producers apply for licenses to produce and sell it. D.C. also just voted to allow personal possession. All of this is on top of the 23 states that allow it for medical reasons.

In some states, where businesses are also now legally cultivating and producing marijuana, a mainstream industry is emerging. Marijuana sales totaled $700 million in Colorado last year, for instance. But there’s a surprising catch. It turns out that indoor marijuana growth in particular — a cultivation method often favored in the industry for many reasons — uses a surprising amount of energy.

Indeed, the level of power use appears to be so significant that one scholar is now suggesting that as the industry grows, states and localities should take advantage of marijuana licensing procedures to also regulate the industry’s energy use and greenhouse gas emissions.  [Read more at The Washington Post]