The number of users has soared while drug-related crime is rising with narcotics now supporting a worldwide business empire second only in value to oil.

I'd say it was of a higher value than oil, if looked at by wieght :)
And the drug industry produces renewable product, so it definitly greener.
New slogan of the green party : "Don't drive! Shoot smack!"

(forgive me, I'm in an odd mood)