Coal WILL be around for a long time, but it needs to clean up it’s act. Wind IS already cheaper than coal per Kwh to produce electricity, but yes, “alternative” will require a mix of energy sources. Solar btw IS getting cheaper, and will probably match or beat coal soon, but there again, yes, we need the mix, same for including nuclear (with new designs and no unnecessary additional mining, as the materials are already available to cover the next 100 years or so, and longer if we “control” fusion.).
ALL energy production has consequences for the environment, and the secret is to use technology to reduce our demand. As natural gas may in the long run prove even more destructive to life than coal, don’t buy the con about fracking being totally “safe”, it can be used in some areas, but is FAR from “safe”.