The Origin of Coal, Oil and Natural Gas: Fossil Fuels or Something Else?

I’m not sure I believe in global warming. I read something written by a scientist arguing that these facts are still open to debate.

I hear comments like this all the time. You can’t put yourself out there as a mainstream believer in the zeitgeist of the scientific community and not receive some arguments from the fringes. As I like to point out, scientific theory is always open to debate. This is why ongoing research and experimentation are always underway. Further information either enhances, modifies, or refutes the current concepts we believe to be the proper understanding of the ways of the universe.

The last time I heard this sentiment was at my book-signing at a local bookstore on Earth Day. It surprised me a little bit because the skeptic admitted to being a grade eight science teacher, and I would hope that people teaching science would be a little more on board with what the majority of today’s scientists consider to be fact rather than adhere to an extremist minority opinion.

The gentleman and I had a long discussion about various aspects of the science and I pointed out that my book was written specifically to help clarify the facts and fill in the gaps for those with an open mind who were keen to understand the current thinking on these topics. Despite our conversation, he decided not to buy the book. (In retrospect, I should have offered him a money-back guarantee if he felt it didn’t answer his questions once he was finished it. Hindsight is always 20/20.)

But he raised one interesting point: he questioned whether oil was even a fossil fuel. He’d read an article about the abiotic synthesis of oil; that is, the formation of the hydrocarbons found in petroleum deposits without them having to come from fossilized plants. If this theory was correct, they could replenish indefinitely from the natural carbon found in the Earth’s crust, essentially a renewable energy source.

I find this a common theme among the more die-hard skeptics: that if they doubt one concept, they will often doubt others. Thus, all of their beliefs will be from the fringe rather than the mainstream. For such extreme perspectives to have any stability, they typically can’t incorporate other well-established facts, but have to use other extreme ideas. So if someone is doubtful of the concepts of global warming and climate change, it helps to doubt the whole concept of fossil fuels having a finite supply. It’s easier to sleep at night. (Although combustion of fossil fuels still adds 30 billion tons of carbon dioxide to the atmosphere each year, regardless of their origin. I never asked him how he reconciles that fact with his beliefs.)

The abiotic synthesis of oil was something I had heard snippets about previously, but admittedly knew very little about. So I decided to explore the subject further to make sure my own “gaps were filled.”

In chapter two of my book, I describe how fossil fuels were formed. Briefly, oil and natural gas were synthesized from the remains of dead plants such as algae and plankton in ancient oceans and seas. These remains would fall to the bottom and form sediments. Over geologic time scales of many millions of years, these sediments became buried deep inside the Earth through the movements of tectonic plates. The high temperatures and pressures deep inside our planet’s crust, along with the anaerobic conditions present during their decomposition, would lead to the formation of the various hydrocarbons found in the oil deposits of today.

Coal is likewise formed from anaerobic decomposition but of terrestrial plants that are buried deep in bogs. They go through a process known as coalification first forming lignite, then bitumen and ultimately anthracite, the purest form of coal.

This biogenic theory of the formation of fossil fuels was first put forward by Georgius Agricola in the 16th century, and the majority of geologists today still consider it to be the most correct theory. Thus, fossil fuels are not a renewable resource because we’re consuming them at a far quicker rate than can ever be replaced.

The abiotic theory for the formation of oil is an alternative theory to the biological origin described above. It suggests that petroleum was formed from deep carbon deposits dating back to the formation of Earth and was first proposed as a hypothesis in the 19th century by Alexander von Humboldt. it received support from some notable scientists including Dimitri Mendeleev who created the current version of the periodic table. The theory was largely forgotten after it was first introduced although gained some popularity in the late 20th century in the Soviet Union. In the English-speaking world, Thomas Gold (1920-2004) was its biggest supporter, and wrote a book in 1998 entitled “The Deep Hot Biosphere” on the topic.

The theory suggests that the biology found on our planet followed the oil deposits and not the other way around. One argument supporters use is that methane has been found on Saturn’s moon Titan, and obviously wouldn’t come from fossilized lifeforms there.

The abiotic theory is controversial and has a number of flaws, however. For one, it doesn’t predict deposits of oil as well as the biogenic theory does. Oil deposits are typically found close to fault lines because that’s where two tectonic plates meet, and ocean sediments can be more easily buried in those regions. Also, oil deposits usually have biomarkers, little telltale signs of life. For the abiotic theory to work, those markers have to be explained somehow; it fills in that hole by suggesting microbes must have been feeding on the petroleum. The biogenic theory easily explains why such evidence of life would be present, however, given that they originated from the remains of once-living plants.

Most of the world’s geologists generally disregard the abiotic theory and it doesn’t have much support in mainstream scientific journals today. Although hydrocarbons with a low carbon:hydrogen ratio such as methane can be produced from abiotic mechanisms—explaining why methane is indeed found on Titan—longer chain hydrocarbons such as octane found in Earth’s oil deposits can only be adequately explained if they are fossil fuels.

When the grade eight science teacher supported his skepticism of global warming by bringing up this abiotic theory of petroleum formation, I realized I wasn’t going to win him over with the facts. I can educate a skeptic who is open-minded and needs some gaps of knowledge to be filled. However, many of those who doubt mainstream science are often suspicious; some even hold onto conspiracy theories, believing people like me have hidden agendas when we try to argue that a change toward renewable energy sources is needed to reduce our carbon footprints. These skeptics will often hold onto any nugget of “science” that can support their position and frequently try to refute the mainstream opinions held by the scientific community.

A tough group to win over indeed, but I appreciated the opportunity to discuss the subject because it led me to learn more about this alternative notion on the origin of fossil fuels. I’m happy to report that further study has only solidified my belief that the mainstream scientific community has once again prevailed. The more ammunition I have to argue against such fallacious arguments, the better I can do my job.