Not so green: how the weed industry is a glutton for fossil fuels

Producing a few pounds of weed can have the same environmental toll as driving across America seven times - harming cities' and states' plans to curb emissions

As he opens the steel door to the jumble of his office, located in a cloistered warehouse on the west side of Denver, Paul Isenbergh is barking down the phone about a duplicitous business rival. He's wearing a shirt and rust-colored tie. Yards from his desk, rows of drying cannabis plants are strung up on two clothes lines.

Isenbergh spent 30 years as a real estate broker in Florida. When he moved to Denver in 2011, he didn't even know medicinal marijuana was legal in Colorado.