
Ask HN: How do economists see the physical world and natural ressources? - orwin
Or do you know a place where i can find an answer to this question?<p>Is Benjamin Say still the reference in economic equations? Are natural ressources still counted as infinite?<p>Am i wrong thinking that growth = production increase = energy increase (or energy optimization)?
So if the energy stop increasing, growth will only depends on energy optimization, right?<p>Do we have economical theories that work without growth? I thought post-keynesian theory had a better understanding of the human factor than classical, but my readings this past month were less than conclusive concerning a world with no growth at all. Classicals too seems to think that  good economy policies will create growth. Do other model exists? Any reference, books? And i&#x27;m not talking about a FT article, i&#x27;m talking about models or mathematical formulas (i&#x27;m not saying i got a bachelor degree in economics in a month, but i am ready to read more than just  vulgarization and textbooks)(although tbh a textbook would be the best)<p>Sorry for this somewhat political question, i know people like technical ones better but i don&#x27;t find what i&#x27;m seeking and thought i should ask for help.
======
PaulHoule
Economists for the most part do not consider physics. Some might say that
economics is to ecology what astrology is to astronomy.

So far that approximation has held up; we run out of resource X, we substitute
Y and then people mostly forget about X. For all we know people will learn to
mine asteroids many of which are richer in tarry gunk than Saudi Arabia.

I like Howard Odum's work on environmental accounting but in many ways that is
a dead end. He developed a scheme that considers the quality of energy as
opposed to quantity. "Emergy" is embedded energy traced back to sunlight, even
the energy it takes to make fresh water. Energy in the form of plants, liquid
fuels, and electricity all have a emergy/energy ratio (transformity) of
200,000.

What makes it a dead end is that uncertainties interact with ideology. David
Pimentel would look through the literature and find the most pessimistic
numbers, industry boosters find the most. When your formula looks like the
Drake equation those factors really make a huge difference.

~~~
orwin
I will read Howard Odum, the concept of "emergy" is interesting. I've read
about the concept of "exergy" as usable energy (50kcal in a liter of water
have a different exergy than 50kcal in an olympic swimming pool), if i
understand what you're saying, emergy is energy that came from outside our
system, that can be used to reduce entropy?

The approximation stopped to be true in 2005 for gaz and in 2006 for oil in
western europe (EU + norway). The curve of oil consumption correlate heavily
with PIB growth in Italy and Greece since 1980 and the change in energy
consumption predated the change in production in these countries since 2006
(the energy crisis created a small production crisis 2 year before the
subprime crisis in Italy and Greece). I think i saw the shell oil (+ Saudi
arabia/russian attempt to break the market) correlate with growth in Europe
around 2014 too, but i'm not sure if i can interpret those correctly. Anyway
oil and gaz production seems to have reach a plateau in 2019 pre-covid.

I was researching postkeynesian vision of economics for myself and pointless
arguments with a friend, i'm pretty sure i found something even more
depressing.

~~~
PaulHoule
At this point there is little fear of running out of oil and gas. The
hydrofracking technology that is applied in the United States would work in
many other places.

The real problem is global warming. The IPCC is only allowed to show
projections until 2100, but if you run the models to 2200 you start
questioning the survival of mankind.

There is the good news that U238 + n = Pu239 and Th232 + n = U233 but it
hasn't been an easy road.

