All this boils down to some of the most poorly understood aspects of climate science: are we better off raising carbon levels now in order to better reduce them in the future, or is it more important (from the perspective of various feedback loops, etc.) to keep levels from ever going over a certain threshold, even if that means more overall emission down the road? We simply don’t have an answer to this question, but it suggests that the climate/carbon argument for a renewables transition is, at a minimum, built on a shaky and uncertain foundation. The real problem is that–much like broader discussions of the renewables transition–the uncertainty in the carbon-reduction argument for renewable energy flies under the radar because nearly all involved in the discussion use very high EROEI figures for renewables. If these figures, as I have argued, could actually be 10x lower than current estimates, then much of the current debate is off track.

None of this is to suggest that we should use uncertainty to abandon action, to stop efforts to transition to a sustainable society. However, we must accept this uncertainty in deciding HOW to best make that transition. More centralized wind and solar and a better grid might be the answer. It might not. Maybe the answer is decentralization and radical reduction in energy consumption? As I’ll address in the future, structurally self-interested participants tend to argue for the former solution–you don’t hear GE raising the uncertainties and potential socio-political pitfalls of centralized wind or solar. Unfortunately, we’ll only find out if their confidence in our ability to transition was misplaced after such efforts have conclusively failed…

Jeff Vail: The Renewables Hump 8: Concluding Thoughts on EROEI and Carbon