Heard That Petroleum Isn’t A Fossil Fuel? Here’s Why It Is – Although Not From Dinosaurs

There are, however, some people, including a handful of scientists, who will tell you oil is not a fossil fuel at all. 

Some of these are Young Earth Creationists, who claim the Earth is only a few thousand years old, and therefore couldn’t possibly have had time to turn ancient algae into oil. We’re going to assume that if you’re reading IFLScience, you’re not susceptible to that particular brand of anti-science.

However, there are other abiotic oil advocates who accept the age of the Earth, and push their claims in ways that we sometimes see shared on social media by people who should know better.

It’s important here to distinguish between three versions of the abiotic oil hypothesis. 

One version claims that some of Earth’s crude oil comes from non-biological processes, but not necessarily a lot. A more radical version proposes that this abiotic oil is abundant and makes up much or most of the oil that's fueled our cars for a century. The final version holds that new oil is being created all the time, and therefore represents an unlimited resource. 

The first of these has plenty of scientific support; it’s not what this article is responding to. The second has far less evidence behind it, but it’s the third – sometimes known as the strong abiotic oil theory – that is least likely and most dangerous, being promoted in support of policies that threaten our future.

Why it matters

People who hunt for oil naturally want to know how and where it formed, but they’re not usually the targets of articles claiming oil has a non-biological origin.

Promoters of the second and third versions described above claim there is a great deal more oil available than geological studies report. If that’s true, then we’re not going to run out any time soon.

Under the strong version of the theory, we will never run out. 

Consequently, proponents argue, we don’t need to be looking for alternative ways to power our cars or airplanes; “drill baby drill” for centuries, perhaps forever. That would be a catastrophic idea for the climate and our lungs, which is why the people pushing abiotic oil are often the same ones promoting climate change denial. 

Undermine confidence in the two scientific observations that underpin the need to move away from burning fossil fuels, and many people will decide to stick with what they know. Support for government programs to subsidize public transport, electric cars, and research into alternative sources of jet fuel has been partially driven (sorry) by perceptions that oil is running out. 

If enough people think supplies are endless, or at least will last their lifetimes, those programs will be more endangered than they already are.

There are also more localized implications. Abiotic oil occasionally becomes popular in countries that have found little to no oil of their own. If people come to believe oil companies have been looking in the wrong places, it’s not hard to convince them there’s oil under their feet just waiting to be tapped, solving the problem. It might even make the whole country fabulously rich. 

If those spreading the idea can pin the blame for the fact no one has found the oil they promise is there on their political opponents or an ethnic group they'd like to demonize, all the better for them.

Usually, however, if no one has drilled for oil in a particular region it’s because there wasn’t an ocean there at the relevant time: no ocean, no algae to settle. 

When oil drilling has taken place and came up dry, abiotic oil proponents who want people to believe the oil is there have an easy answer – the drilling just didn’t go deep enough. 

After that, the hypothesis bleeds over into conspiracy theory. Some mysterious cabal is causing drillers to stop just before they’re about to hit abundant oil, the story goes, sabotaging the national interest for a mysterious agenda. It’s not hard to see how these ideas can easily be weaponized into racism.

Moreover, if people become convinced that tens of thousands of petroleum geologists are conspiring to hide the truth that oil is almost infinite, they’re more likely to believe other scientific bodies are lying to them as well. 

That could apply to almost any field of science, but once someone decides supply limitations won’t stop us burning oil forever, they’re particularly prone to concluding the threat to climate isn’t a restriction either.

Arguing from astronomy

Titan is covered in hydrocarbon lakes and seas, but we don’t consider this evidence of ancient life. Similarly, methane is common in the Solar System on lifeless planets and even comets. 

Consequently, even if Earth had no life, it would probably have methane, and possibly some more complex molecules.

Since oil and what has been branded “natural gas” are often found together, it’s possible to jump from the argument that Earthly deposits of methane could be formed from non-biological processes, to the assumption that most are. 

Moreover, since longer hydrocarbon chains, such as those that made up crude oil, can sometimes form methane without biological drivers, it’s not impossible that some oil has biology-free origins.

It’s a big jump from that to saying the vast reservoirs of Venezuela, the Persian Gulf, and the Canadian Oil Sands formed without ancient microorganisms, but it is one some people are willing to take.

Scientific reviews have noted that the conversion of methane to “higher hydrocarbons” requires the presence of hydrogen gas. Although deposits of natural hydrogen exist on Earth, we don’t know of any remotely large enough to form the planet's major oil deposits.

Chemistry has a say

Crude oil deposits are mostly composed of fairly small molecules like octane (C₈H₁₈), but also contain a wide variety of much more complex molecules. These frequently resemble molecules essential to life, such as chlorophyll. 

The more complex the molecule, the harder it is for it to be made abiotically, and the range we have found is remarkable. As far as we know, nothing like this exists on Titan or elsewhere in the Solar System.

The carbon isotope ratios in petroleum deposits also match those captured by living organisms, which are not quite the same as background. 

Proponents of abiotic oil like to argue that the bulk of the oil formed at depth, and on the way to the surface mixed with molecules left behind by life-forms. It’s awfully coincidental, however, that everywhere oil got close enough to the surface for us to mine, there were always abundant organisms that left their calling cards in the oil as it rose.

Putting abiotic oil to the test

Like a lot of things that are now mostly promoted by conspiracy theorists, the idea of abiotic oil was not initially pseudoscience. 

Such giants of science as Mendeleev had speculated about the possibility without much detail, and Russian scientists explored it during the mid-20^th century. In the West, it was independently proposed by Cornell Professor Thomas Gold in 1977.

Gold set out to test his ideas by drilling into meteor craters. He thought the shock of the impact might have opened fissures that would allow the hydrocarbons to migrate from the mantle to close enough to the surface that we could find them. 

His first drill found some oil, but the uncontrolled way the drilling was done left the source disputed.

Gold’s subsequent efforts also hit small amounts of oil, but the quantities were insufficient to be commercially viable. 

There were also signs that what Gold had found was likely made by microbes living at unexpected depths. The work may have told us something interesting about the deep geology of the planet, but there was no evidence it had any bearing on how economically significant deposits are formed. 

Gold also championed the idea that ecosystems could exist far underground, which he called “The Deep Hot Biosphere”. His experiment is now considered a breakthrough in proving that idea, with some of those life-forms being methane producers. 

That aspect of Gold’s work has been influential in thinking about the quest for life on Mars. As a test of the idea that large oil deposits could be the product of non-living chemistry, however, the efforts are generally considered to have disproven Gold’s theories, rather than supported them.

Almost 40 years later, we’ve punched holes in the Earth in a great many places, often to extraordinary depths; useable oil deposits have only turned up on the floors of ancient sea-beds or very nearby.

Abiotic doesn’t equal everlasting

As noted above, abiotic oil is often promoted as a counterpoint to the idea that we will eventually need to stop using gasoline and diesel to fuel our cars, so best to stop now. 

However, in 2010 a team of authors led by Dr Mikael Höök of Uppsala University noted that even if oil has a non-living source, these claims don’t hold up.

Fears that we will run out of oil prompt some to imagine a future where we quite suddenly hit a wall, having used up the last barrel. For more than 30 years, however, it has been known that this won’t happen. Instead, if we don’t move to better technologies first, the world will encounter “Peak Oil”, after which the amount that can be economically extracted will fall year after year, forcing prices to rise.

“We show that peak oil is first and foremost a matter of production flows,” Höök and co-authors wrote. “Consequently, the mechanism of oil formation does not strongly affect depletion. We would need to revise the theory beyond peak oil only for the extreme – and unlikely – hypothesis of abiotic petroleum formation.”

More than 50 countries had passed peak oil production at that time, Höök and co-authors pointed out. Few of them have cut back out of environmental concerns. Instead, they have found the prices rising as the best wells are played out, and have reached a point where it’s not economical to pump petroleum at the old rate, or in some cases at all.

If abiotic oil is so abundant, or being replenished all the time, it’s strange that none of these countries have found their wells refilling.