Stronger on the "not releasing sulfur/radioactivity/etc." front than carbon, since you are still burning stuff for heat. It's just that the stuff you're burning hasn't needed a few million years composting underground first. How the whole process to get it to the tank stacks up in terms of energy efficiency and environmental impact compared to traditional fuels I don't really even know how to begin to research beyond seeing what google can dig up.
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‎noli esse culus
‎noli esse culus