"Will the growth of the new gas industry seriously slow down new energy development?"

It already has. There is a resistance by corporate energy to alternative sources.


"What will be the environmental cost?"

Fracking is far more hazardous than solar panels. It leaks dangerous chemicals into ground water and you can set your water tap on fire in Pennsylvania. It has produced biological problems from asthma, headaches to physical debilitation in people who live in fracking areas.

The nuclear alternative is far worse. It heats up the planet at a faster rate than coal burning plants. The chemicals it emits are devastatingly harmful. Cesium 137,
Cesium 134, gasses from uranium, plutonium possibilities....they are just beginning to discover the devastation from Chenobyl and Fukushima world wide.

Any problem with Solar energy is minute comparably.