I should really start, shouldn’t I, by trashing my opponent’s credentials? Science is just a trick or treat parade. Let’s bring out the undead. Wouldn’t it be great if Liebreich was just another arrogant, right-wing, free-market, pro-trade, growth-obsessed elitist with no real grounding in science? Well. He might be some of those things. But when it comes to thermodynamics, at least, he’s no zombie.

Here’s a fun fact. He and I both studied thermodynamics at university, he as an engineer and I as a mathematician. By an even quirkier turn of fate, it turns out we studied in the same place (Christ’s College, Cambridge) at more or less the same time (he arrived there a year or so after I left). And, as it happens, we both weren’t too shabby at it. But let’s not turn this into a pissing contest. We clearly came out of it with rather different ideas about the world.

It may seem picky. But I still believe, naively perhaps, that scholarship matters. The secret of eternal growth doesn’t exactly distinguish itself in this regard. Its generosity towards the environmental Kuznets curve is uninformed. Its grasp of carbon accounting is tenuous at best. Its attempted takedown of Jay Forrester displays all the mistakes that have haunted the Limits to Growth debate. But the crowning glory of the ghouls parade, and of course the thing that is absolutely meant to draw blood, is the claim that ‘when you scratch the surface of any of the seminal tracts of the degrowth movement, you find they are based on the same fake science, right through to the present day’.

The source of this supposedly fake science is a 1971 book called The Entropy Law and the Economic Process written by the Romanian-born mathematician and economist Nicholas Georgescu-Roegen. Apparently, Georgescu-Roegen made the schoolboy error of mistaking planet Earth for an isolated thermodynamic system inaccessible to any inflow or outflow of energy instead of a closed system subject to a continuous inflow of high-quality solar energy. So says Liebreich.

But that’s not even remotely true.

I know this, because I went to The Entropy Law myself almost thirty years ago to support a proposal for a pioneering series of articles on renewable energy that I wanted to submit as guest editor to the journal Energy Policy. This was at a time when the very subject of solar power was still regarded in the UK as the concern of freaks, radicals and Danish people. Getting one paper on renewable energy into a mainstream energy journal was hard enough. Pitching a whole series of articles was positively risqué. But I managed to make my case. And I made it because of Georgescu-Roegen – with the help of Herman Daly, of course.