How this UK-based firm is growing a more sustainable cannabis [Video]

Growing cannabis indoors uses a lot of energy, obviously resulting in higher emissions.

But some companies are trying to combat that like U.K.-based cultivator Glass Pharms. It claims to be the world’s first firm to grow cannabis indoors in a carbon-neutral way. It actually says it goes one better, and produces in a carbon-negative way — without buying carbon credits that would usually offset emissions.

The company’s greenhouse facility in the south of England gets all its power from an anaerobic digestion plant, which is fed on waste food that would normally go to landfill and release methane as it breaks down, CEO James Duckenfield explained to CNBC on a video call.

Carbon dioxide has been used as a unit of reference by the Intergovernmental Panel on …