I'm not exactly a Green activist!
But, crossing the Ashdown Forest recently, I thought: What if they are wrong and fracking does damage the environment? I would hate to see all that fantastic countryside lost for ever.
Having read some geology reports (I do actually have a BSc in Geography and did geology and botany on the course), I understand that earthquakes are unlikely. The process expels no more energy than someone jumping from a ladder. Filling the landscape with reservoirs is more dangerous because of the weight of the water. Having said that, it's not wise to do such things in a fault zone!
However, geologists are concerned with the concrete fillings of the wells, which can crack under pressure, possibly causing contamination. Chemicals are used in the fracking process.
Another concern is that it is an industrial process in the heart of the countryside, bringing lorries, muck, noise etc etc.
My jury is out...