A biochar of spent coffee grounds.
Not coffee grounds.
If you don’t know what biochar is, it’s high carbon material that’s left over after burning organic matter (think:wood) slowly under low-oxygen conditions.
Biochar requires energy and emitting gases.
It seems unfair to say that we’re saving on CO2 and methane from decomposition without also counting the cost of the biochar combustion.
Ironically, doing research is the best way to be right. What people want is to feel right without having to think very hard. Feelings don’t really require energy in the same way that thinking does.