It costs a lot of money and only defers the problem. Extracting less coal and less oil doesn't do much to address increasing energy demands. You'll get some decrease when the price goes up from restricting supply, but once thing stabilize it's going to continue rising.
Basically, you're temporarily reducing emissions without addressing the circumstances that brought about high emissions in the first place.
This thread is for asking any questions that might seem obvious, tangential, silly or what-have-you. Don't be shy, everyone has holes in their knowledge, though the fewer and the smaller we can make them, the better.
Please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.
To any future monthly posters of SQ threads, please remember to add the "stupid_questions" tag.