[lopmotr]

Oh, I've never heard of drowning in rubbish! With 5) I'm referring to geological effects causing landfill land to collapse and get washed away. That happened recently in New Zealand and a river ended up full of rubbish from a disused landfill.

[catalogia]

Sorry, I mean Slate Star Codex's point 5 addresses your point 2. I communicated that poorly.

Incidentally a nice (rather amusing) example from pop culture of the "landfills are filling up and we'll soon drown in trash" meme is Futurama episode 'A Big Piece of Garbage'* (S01E08) It's essentially a parody of that NYC trash barge incident and the movie Armageddon.