blah blah blah, human beings have only inhabited 15% of 30%(the crust above water) of the world. I think we can deal with plastic cases, those plastic cases were derived from plant matter that would probably still decay and release co2 whether we turned them into plastic or not.
last year while moving out of my house, someone stole my games, granted they were in cases, but it makes it that much easier for people to steal your stuff when they're conveniently stored in cd jackets