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Wouldn't it be great if we could just drill into the ground and find pools of a natural energy source? Sure. Well, that's oil.

Oil is generally considered a non-renewable resource. But if humans used less of it - much, much, much less of it - would it actually be a good renewable and sustainable resource?

Of course, there's also the issue of finding a way to use it that doesn't result in global warming. But that's another question.


Edit: Asked the follow-up question here.

3 Answers 3

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What does renewable mean?

Wikipedia defines a renewable resource as (emphasis added):

a natural resource which will replenish to replace the portion depleted by usage and consumption, either through natural reproduction or other recurring processes in a finite amount of time in a human time scale.

"Human time scale" is rather vague, but we can assume it's no more than 10,000 years, which is about how old human civilization is.

How long does oil take to form?

By contrast, crude oil (or petroleum) takes millions of years to form. Per the University of Calgary's Energy Education portal (emphasis added):

The formation of oil takes a significant amount of time with oil beginning to form millions of years ago. 70% of oil deposits existing today were formed in the Mesozoic age (252 to 66 million years ago), 20% were formed in the Cenozoic age (65 million years ago), and only 10% were formed in the Paleozoic age (541 to 252 million years ago).

Because oil takes millions of years to form, there is no way we could reasonably classify its use as renewable.


But what if new oil is still being formed?

There's a great question about this on EarthScience.SE, and while there's no real conclusion, there's a range of suggestions from 15,000 to 80,000 barrels per year of new oil being formed.

Even if we round up to 100,000 barrels, this is a very small amount:

  • It would fit in one oil tanker.
  • It's 1/100th of a percent of the size at which oil fields start to be measured -- one billion barrels.
  • It's 1/10th of a percent of the amount of oil consumed every day at the global level.
  • Put another way, 100,000 barrels would last about 90 seconds at our current rate of consumption.
  • Given a population of 8 billion, everyone would get about 2 ml per year:

Hand holding 2 ml bottle

Don't spend it all in one place!


Note: the 2mL is just in the lower part of the image (the translucent bottle), and not in the top opaque part. So 2mL is even less than this image may initially convey.

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  • Thank you for your answer. I'm not sure this is accurate. It's like saying apples aren't a renewable resource for caterpillars because it takes longer for an apple to grow than the caterpillar will live. If all humans, together, only used 1L of oil per year, surely our planet would produce much more than that annually. So I'm thinking it's not that oil isn't renewable, but that humans use much too much of it. Feb 2 at 0:36
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    Caterpillars can kill an apple tree.
    – Lee Mosher
    Feb 2 at 1:17
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    @Rock - Yeah, we use far too much oil, but the regeneration rate is so minuscule that treating oil as a renewable resource (where human consumption rate is the issue), just doesn't make sense. It's like thinking about the sun: it uses a non-renewable resource, Hydrogen. Sure, eventually it will run out, but does this really matter for humans in 2022? The sun isn't going to run out of Hydrogen until the year 5 billion or so, it's just not a problem on the human timescale.
    – Robotnik
    Feb 2 at 12:00
  • I appreciate how you added a scale amount to your answer and the link to the related question on Earth Sciences SE. I have little insight into the accuracy of all those figures, but let's say it's 100 times off in either direction. That's still a very small amount. Now, if it's off by 1000+ times, that leads to conclusions that are quite different. Continued... Feb 2 at 12:17
  • What is also a challenge is estimating how much oil each of us actually consumes. Directly, perhaps outside of fueling a vehicle or home, most people don't use much oil directly (not to minimize those 2 large forms of consumption). But many people use products and services that require oil to produce or transport. For example, I use very little oil directly (I currently use less than 2L per year), but my indirect use is completely unknown to me. All I know for sure is that my indirect use is greater than zero. A website/app on which one could estimate indirect use would be an asset. Feb 2 at 12:22
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I'll provide a different answer to this.

Fossil oil isn't something that is being produced at a great rate currently. So the 2 milliliters per year in the other upvoted answer is probably a good approximation.

However, a chemically equivalent liquid, renewable oil, can actually be produced in scales reasonably close to the scales oil is being consumed today. We still have to reduce our oil consumption, perhaps to 10-20% of what it is today, but not more.

For example, in this year, 19.5% of the energy content of fuels sold in Finland have to be from renewable sources. This percentage gradually rises to 30% in 2029. And the decisions were made before the accelerating adoption of electric vehicles. So the 30% was assumed to be realistic given our current rate of oil use. Realistically electric cars will make about 15% of the cars in use in 2029, so it's probably realistic to have even 35% of energy content in fuels be biofuels. Part of the 30% target will probably be bioethanol, that is not chemically equivalent to fossil fuels, but a lot of it will be next-generation biofuels that are chemically the same compound as the fossil fuels.

Every compound in oil can be made from renewable sources. The trouble is, we can't maintain our current rate of oil consumption and produce 100% of oil from renewable sources because there aren't enough feedstocks. However, if all light road transportation (passenger cars, vans, etc) become electric vehicles and only heavy trucks, buses, industrial and agricultural equipment, marine transportation, and aviation continue to use oil, the remaining oil users can very well use oil at their current rate of oil consumption. The oil will be renewable, but the vehicles don't need to care about that. It's still chemically the same compound.

If we consider more drastic measures, such as eliminating every single tropical rainforest on this planet and replacing them with oil palm plantations, we could probably replace even 100% of oil use from renewable oils. However, renewable does not equate to environmentally friendly, if rainforests were destroyed there's nothing environmentally friendly in that.

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  • Personally, I'm optimistic that there will be a "trickle up" effect -- EVs will take over for passenger vehicles, and technology advancements/efficiencies of scale will make the technology viable for heavy equipment, continuing up the chain until eventually even electric airplanes perform better than their jet-fueled counterparts. The question is how long this takes!
    – LShaver
    Feb 2 at 17:40
  • @LShaver feasability depends on how much minerals we will have to extract for it... with what energy.
    – J. Chomel
    Feb 3 at 10:14
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Countries like Saudi Arabia can pump oil out of the ground with very little effort. And then the supply of oil is something like 300 years. Now, deep-water oil wells are high-margin operations but exploration is required to find them.

But terminologies like "sustainable" and "renewable" are political terminologies with specific purposes and limited applications. A better terminology would be "carbon-neutral".

So oil could be pumped out of the ground, reformed to hydrogen with the carbon-dioxide captured, and be carbon-neutral. Or that process might be more correctly called "zero-carbon-release". But current blue-hydrogen processes mostly use waste methane or direct natural-gas and not oil.

But the oil companies are now talking about second-generation ethanol. And so second-generation ethanol could be carbon-neutral. Ethanol produced from lightly-fertilized sorghum could be carbon-neutral, ethanol produced from waste wood chips could be carbon-neutral, and ethanol produced from waste agricultural produces could be carbon-neutral. Some of these processes are going for "sustainable" jet fuel. Now does "sustainable" mean "carbon-neutral" ? Well, the accounting method of carbon-neutral needs to be considered and some processes might depend on a perverse logic to be carbon-neutral but they are safely "sustainable" and "renewable".

Then there are processes for production of synthetic methanol and synthetic gaseous gas. Carbon-dioxide is captured from industrial processes and combined with green-electricity to produce these synthetic fuel products. But are these processes carbon-neutral or are they two uses of one carbon-release ? How should they be accounted ?

And so "sustainable" and "renewable" can simply be administratively determined while "carbon-neutral" would require a rigorous accounting.

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