Ask HN: When will the industrial society deplete the energy resources on earth? | Hacker News Reader

Ask HN: When will the industrial society deplete the energy resources on earth?

37 pointsroschdal17 comments

When will the major energy resources on earth (coal, gas, oil, nuclear) be depleted? Give your best estimate please.

https://octopus.energy/blog/when-will-fossil-fuels-run-out/

> If we keep burning fossil fuels at our current rate, it is generally estimated that all our fossil fuels will be depleted by 2060. New reserves will probably be found before this point, extending the deadline somewhat, but its worth remembering that if we are to limit global warming to the 'relatively' safe level of 2C by 2050, 80% of coal, 50% of gas and 30% of oil reserves are "unburnable".

Then, may I present to you, Lawrence Livermore's Energy Consumption Resource Flow diagram: https://flowcharts.llnl.gov/content/assets/images/energy/us/...

summary (1 quad = 10^15 btu)

  ~32 quads of all energy input comes from natural gas

  ~9 quads of all energy input comes from coal

  ~32 quads of all energy input comes from petroleum

  industrial sector is estimated at about 49% energy efficient, compared to residential + commercial sector's 65%, and transportation's measly 21%


  62 quads (aka roughly 2/3rds!!!) of all energy output just dissipates into the environment, as 'rejected energy'

Yes folks, you read that last one right. Electrification + cleaner energy sources can't come soon enough.

I wish theoildrum was still running, since they devoted a lot of intellectual effort into exploring questions like this in great detail. For oil you need the Hubbert Curve: http://theoildrum.com/node/7072

Remember that depletion is asymptotic, so a possible answer is "never"; extraction just gets smaller and smaller. Individual wells work like this anyway, what comes out is an oil/water mixture at gradually reducing pressure. At some point it's uneconomic to pump and filter it, so it's capped off when not empty.

I can't guess on the ones you stated but if for completeness sake we include geothermal then probably about 3 or 4 billion years, long after the planet would have to be evacuated for different reasons. Ubiquitous deployment of geothermal is challenging at this time due to the current tech limitations and associated costs.

The EROI of oil has dropped steadily over the years and has probably dropped below 8 now (8 units of energy produced for 1 spent): https://bylinetimes.com/2021/10/20/oil-system-collapsing-so-...

This other article has a graph that shows why 8 is critical threshold. Dropping below 8 means production rapidly starts to consume all of the energy produced. http://theoildrum.com/node/8625

Economics finds a way. Prices go up the rarer it is. We had prices for petroleum go up several cents per liter, and people here switched to natural gas vehicles.

EVs are a "fad" now but once prices go up a little more, people will switch. Energy companies charging more to match scarcity will just get switched. Right now it's not economical to do more solar or "microwave" power plants, but if prices go up, a lot of smart people will enter this sector.

Nuclear fission might be a more interesting question, because that's the main fallback. But it should last long enough until people figure out fusion.

Never. Their price will steadily rise as the easily-accessible sources are depleted, until it becomes uneconomical to use them.

We'll likely see gasoline phased out for transportation by 2030-2035. Kerosene is still going to be used for jets and rockets for the foreseeable future; there are no good substitutes. Coal is already on its way out for electricity generation, and disappeared from railroads and ships about 70 years ago. Plastics are also here with us for the foreseeable future; they don't use much oil, and they give a lot of product benefits that can't be replicated with other materials.

Effectively never. As technology improves, new reserves that weren't recoverable before become so. EG fracking, shale oil, tar sands etc.

I think we will have a suitable replacement for oil long before it runs out. Likewise gas etc.

https://www.nytimes.com/2009/08/25/opinion/25lynch.html?_r=1...

Never. Coal, gas, and oil are all renewable resources. Folks just don’t care for how long it takes.

(ducks)

My understanding is that no, they aren't.. as there are now fungi that can break down lignin, and so coal isn't ever going to be formed in those quantities ever again, no matter how long you wait.

Good point! The carboniferous era must have been a hell of a time, wish I could have seen it.

A Billion years is a long time , who knows what will have evolved by then

Life finds a way

Coal contains very little lignin. Coal is still being formed in bogs, or anywhere acidic and anaerobic. Anaerobic fermentation is still used to stabilize harvested bamboo. Bamboo stem contains sugar making it susceptible to termites and rot. Bury it in riverbed mud, bacteria will quickly break down the sugar before the lignin and cellulose, then you pull them ashore and wash mud off to stop the reaction.

Before this fungus came along, trees would fall over, and just pile up, every forest was a vast carbon sink, no matter how soggy the ground was. That's where our fossil fuels came from.

Never as our main energy source is the sun. Even fossil fuels are just stored solar energy. Of course there is other minor sources of energy like chemical or nucular energy, but even those came from some star/sun at some point.

Thousands of years to probably never. I say that because we will likely switch to newer technologies that no longer use these limited resources before they run out.

Wednesday.

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