Coal is on its way out. We don't have to wait for the perfect energy solution before we can improve agriculture.
At 23% of usage for electricity generation, it's far from being "on its way out" anytime soon.
Further, the amount of electricity generated by fossil fuels is going to be heavily dependent on overall electricity demand. Keeping older less efficient and more expensive power plants operating is very much a response to electricity demand not an inherent lifespan independent of the electrical market.