system
Given the following post, respond as if you're commenting on Reddit:
human
How clean is "clean coal," as opposed to regular fossil fuels?
gpt
The idea behind clean coal is that you are capturing the carbon dioxide before it's emitted, compressing it, and injecting it back into the earth.

The main sources of pollution with coal are:

1) Environmental damage during mining

2) Carbon dioxide emitted during burning

3) Other pollutants emitted during burning (sulfur dioxide leads to acid rain; heavy metals; black dust)

We already control (3) to some extent through scrubbers, by washing the coal before burning, etc. Clean coal hopes to control (2) as well. But (1) will still be a problem.

You can't really compare coal to other fossil fuels -- coal cannot directly replace oil (since it is used to produce electricity rather than for transportation). But, clean coal is a lot "cleaner" than oil, since we can stop most of the carbon dioxide from being emitted. Carbon capture is not plausible for individual cars.