One way to think about fossil fuels is as "natural batteries". They are naturally stored energy sources (ancient sunlight) in large highly concentrated quantities - which makes them incredibly cost effective and reliable.
Manufactured batteries, attempting to store an intermittent flow of sunlight or wind-energy, are much more expensive and very unreliable. There is no single self-sufficient solar or wind-powered electricity grid in the entire world. They are all backed up by fossil fuel sources. Increasing renewable generation will actually increase the demand for fossil fuel backup.
To suggest that the climate side effects of fossil fuels requires us to dispense with them is nothing short of lunacy - a program for massive value destruction and all that that implies for billions of humans around the world.
