Did the 1972 Limits to growth model include the exponentially decreasing price of PV energy ?
Did it model solar energy at all, or does it not take these things into account ?
From A Synopsis: Limits to Growth: The 30-Year Update:
Don’t take that as a summary of the article, though – quite the opposite. It’s worth a read.
In any case, that’s the same argument against Malthus (who made essentially the same argument regarding exponential growth). Malthus was wrong historically, but in the long run, he just might have been right.
Of course there are ultimate limits. But if you think about the available resources, instead of looking at the methods at the time, you realize the limits are vastly higher than you might otherwise think.
Food production - you don’t need arable land. Shipping container farms are apparently drastically more productive per unit volume and per water. Also, if you really want high performance, Soylent is working on genetically engineering algae to use as an ingredient in Soylent like foodstuffs. One 100k square foot warehouse full of algae growth tubes and high intensity lighting is apparently enough to feed LA. I haven’t checked these numbers myself, but they do fit other numbers on spacecraft life support so I believe em.
Water - you can recycle shower water in a direct loop, barely use any for toilets, use almost zero for agriculture if you do algae in sealed tubes or shipping container farms, etc etc etc. Not a problem.
Hydrocarbon fuels - what the fracking boom should tell you is that in a “played out” area of the world there’s actually a huge amount of oil and gas left. What about the shallow spots in the ocean? Continental Europe, Asia, Africa, Australia…there must be vast frackable reserves as of yet unexploited.
Minerals - humans have only ever mined for ore in a limited fraction of the Earth’s landmass. Some nations never had the capital or the infrastructure for real mining - parts of Africa, Siberia, etc. Then there’s a whole continent that is untouched, Antarctica, and the ice may conveniently melt away in the next century. Then there’s the ocean floor, or 2/3 of the Earth’s surface totally untouched.
And so on.
I have somewhere in my basement boxes a book I bought a few years after “Limits to Growth” which was a critique of it. I think it was called “Thinking about the Future: a Critique of Limits to Growth”. It made the point then - still valid - that there was no allowance in the original book for technology or market substitutions, or even scarcity as a driving factor in changing the limits.
We can point to many situations where Limits was right - collapse of fisheries in many places (I.e. Gulf of St. Lawrence) or oil shortages - but plenty of other situations where some changes have moved the goalposts substantially - solar power, hybrid vehicles, fracking, drip irrigation and the green revolution, the coming demographic bust in the first world…
Space-based solar power would vastly increase the amount of growth possible on Earth. Mine the Moon (using solar-powered mining equipment). launch an arbitrarily-large cloud of solar-power satellites into the Earth- Moon volume, and beam power back to Earth. This would give us enough power to produce fresh water, food and other requisites for a population many, many times larger than today.
Eventually the Earth would start overheating from waste heat rather than carbon dioxide - but hey, you can’t have everything.
I think i can sum those posts up as - nobody knows. Who the hell wades through hundreds of pages of report just to see if it models solar power efficiency gains properly ? I know I don’t.
Where would be a good place to ask ?
(I don’t accept fracking as a long term thing, BTW, depletes quickly.)
That is an idiosyncratic take on ‘convenience’.
Mining in Antarctica is not going to happen, anyway. We’ll be strip-mining asteroids before mining in Antarctica happens.
At least you’ll have a whole lot of new port towns from which to sail your supply ships…
IMO **md2000 **provided your properly cited answer.
Which seems to be that as a matter of policy the original report assumed zero human tech or economic progress. IOW, it asked and answered the question: “If humanity changes nothing but their numbers, when and with which resource(s) do we hit a/the wall?”
Which is certainly a valid question to ask & answer. And given the limits to numeric modelling tech in 1972, was challenging enough.
Well, fair enough. I’ll have to google it up and see.
Actually looking at this -
- the authors say they did include technological advance, markets, efficiency and substitution.
But I’d like to know how accurately they did so.
Play with the world3 model here