Stuart at Early Warning has one of the better blog post titles I've seen in a while, commenting on John Michael Greer's recent pessimistic posts about solar power - Limits on the Thermodynamic Potential of Archdruids.
I often read John Michael Greer, the Archdruid. He's a smart and thoughtful guy who worries about some of the same things I worry about, though he tends to have decided they are all hopeless, whereas I tend to see society as having a lot more options than he perceives. He has read very widely and often comes up with interesting historical analogies that hadn't occurred to me, so he's well worth the spot in my reader.
Where he tends to go horribly wrong, and why I think his overall take on the subject is too negative, is when he tries to talk about physics. In a recent series of three posts:
* Energy Follows It's Bliss
* An Exergy Crisis
* Barbarism and Good Brandy
He has been trying to argue that there are fundamental physical barriers to society surviving the transition away from fossil fuels, and getting horribly snarled up.
Now, I am not a working physicist, but I may well be the nearest thing that will admit to reading the Archdruid - I trained in Physics, have a PhD in the subject, and then went into Computer Science. But the points at issue are pretty elementary here, so let me try to straighten the Archdruid out, and at least place something in the record for anyone that might be confused by his arguments.
In short, there are no fundamental physical barriers to a non-fossil-fuel based economy - the main problems are social, economic, and practical, not issues of physical law.