[thfuran]

>do you mean burned or unburned carbon?

I'm not sure what distinction you're trying to draw.

>And since we are still pumping oil of the ground, leaving a different form of oil (plastic) in the ground doesn't accomplish anything useful.

I suspect that overall energy production in the US probably emits less CO2 per kwhr than burning garbage does, so starting to burn garbage for energy would be, in that regard, a net negative. Furthermore, it would likely require moderately significant capital expenditure that could've instead been used for something better.