It's like comparing a lake with an inch of water in as opposed to a bath-tub filled to the brim.
Getting off coal would only mean a reduction in the standard of living in the short term if we abruptly ended all coal-based power-generation and related activities. Getting off coal would mean an increase in the standard of living in the long term because the replacement technologies require a higher level of expertise, which means an increased demand for educated professionals and higher-quality materials and thus a higher value on education. There is no place wherein well-educated, well-paid individuals see a decrease in their standard of living from that. Go anywhere with an abundance of highly paid, highly-educated individuals and you will see nothing less than a high standard of living.