The danger of coal - need SPS

All energy is, to one degree or another, interchangeable. If our major
energy source becomes SPS rather than oil and coal, electric cars will
likely have advantages; bio-fuels (ethanol, bio-diesel) fertilized by
electrically generated fertilizers could fill in for those still tied
to internal combustion. In principle eletrically generated hydrogen
could work, but in practice it looks like other options will be more
efficient and less expensive.