Actually, the archaic cannabis laws are responsible for most of this and when those laws change, the way people grow will also change. So I see the changing cannabis laws as doing more than LEDs. The prohibitions against cultivation force people to grow indoors when they may prefer to grow outdoors or to gorilla farm because they cannot legally grow on their own land.
Articles like this irritate me--pretty much sensationalized journalism IMO. Their "facts" come from the Office of national Drug Policy and the Forest Service--both government agencies, both pretty much anti-cannabis. I see someone has estimated that you can make 18 pints of beer for what it costs to produce 1 joint (I question this), but how much did alcohol cost to produce and what was the damage done to the land when prohibition was in force? How many of these things would be non-issues if cannabis was legal?