Prof Catherine Mitchell, who is professor of energy policy at Exeter, has written a critique of Dieter Helm's book (which I must get hold of soon).
I enjoyed the wonderful understatement on shale gas:
Helm’s final piece of the jigsaw, which he sees as the outcome of his solutions, is for gas to displace coal and to be the short to medium term transitional fuel until these ‘future’, including renewable energy, technologies kick in. This requires abundant global gas and although we know the recent shale gas finds have increased the global gas resource we still do not know what either its environmental or economic costs will be, particularly if large swathes of the globe move to gas. This policy therefore risks security and (increasing) price problems; including greater numbers of fuel poverty.
I don't think the expression "increased the global gas resource" quite does justice to the shale gas revolution of recent years.
As to not knowing the economic costs, that seems a bit of a stretch. The consensus is the USA seems to be that shale gas extraction will be economic at $6/mmBTU, a figure that will no doubt fall as the technology develops. In the UK, where shale gas seems to be in much thicker deposits, we might hope that extraction will be cheaper still.
The environmental costs again are very much a known quantity - fracking is of course a venerable technology and there can be little doubt that it can be done with minimal impact on the environment. Environmental risks seem to be very small. In fact it's hard to imagine a more benign form of energy.
I worry when university people speak about shale gas extraction as being an environmental concern because it suggests that they are publicly funded campaigners rather than objective researchers.