Energy and minerals
Energy and minerals drive modernity, science, convenience, space exploration etc..
Pre-collapse
Human trajectory
Our planet (+ barren mars, hypothetically) is finite. Can’t add in other star systems - too far away to benefit those here.
We grew exponentially, exploiting and even recklessly wasting resources.
So, cannot sustain current rate of resource exploitation and pollution.
After that will be a grind down to stone age before ultimate extinction.
Resource wastage, wars etc.. can speeden the decline.
Resource wastage
As we fecklessly extract minerals, oils and gasses - and then waste them frivolously, we will soon not be able to extract them given our limited energy. This rate of resource extraction and waste cannot be sustained indefinitely.
Fossil fuel wastage
Humanity’s wastes highly undervalued fossil fuel.
It could’ve been better and more safely rationed out for developing cleaner energy sources, plastic manufacture, near-space colonization, delaying industrial collapse etc..
Instead, it is burnt, leading to global warming and such.
Ores
All sorts of mines were richer in the past - Cu, Au, Ag, Al, Fe .. Many were totally exhausted, despite miles and miles of tunnels.
End of economic growth
Over-reliance on a limited store of frozen sunlight has led to rapid economic growth.
This economic growth, being dependent on energy-usage growth, resource exploitation and population growth is not sustainable.
During collapse
There will be widespread famines, social unrest and depopulation.
Energy
Some tech (nuclear breeder reactors, PV energy) may provide energy while they last.
Planned use
If one thought long-term, about the coming mostly-stone-age a few kilo-years later, one would use the current energy wealth to -
- make and store lots of copies of texts ( http://rebrand.ly/dg-archive )
- make billions of stone tools (tools + weapons - axe-heads, knifes, plough-heads …), magnifying glasses
Other ideas - please contact me.
Post collapse
There might be islands of civilization which can manage advanced thought and material comfort.
It will be the time of adventurers and technomages.
Energy
Long term
Solar thermal, and hydroelectric power plants would be fairly cheap and low-tech.
Minerals
Minerals will be scarce, but will be obtained from recycling and some high-energy techniques.