Are oil and gas ‘renewable sources of energy’ as claimed by some?

By Vivek Saini 

In the era of instant information and viral content, social media acts as a hub for stimulating debates and unconventional ideas. Recently, we encountered a post challenging the widely held belief that oil and gas are finite remnants of prehistoric life, asserting instead that they are sources of renewable energy. The origin of petroleum remains a contentious topic among scientists, with the abiogenic theory, suggesting Earth’s internal oil formation, finding support from some researchers. If valid, this theory could explain the abundance of oil and offer hope for its replenishment. In contrast, the biogenic theory, linking oil to ancient life forms, is bolstered by significant evidence. This ongoing debate highlights the intricate nature of our understanding of oil’s origins and its potential impact on future energy resources.

Debate Over Petroleum’s Origin

The source of petroleum remains an intriguing and controversial topic in the scientific community, with two primary theories in contention: abiogenesis and biogenesis. Abiogenesis, the older theory, suggests that petroleum had an inorganic origin, forming beneath the Earth’s mantle long before the current life on our planet. Dmitri Mendeleev introduced this theory in 1877. In contrast, the biogenic theory proposes that petroleum arises from ancient biological materials transformed by high-temperature processes, all without the presence of oxygen.

The widely embraced perspective is that the oil and gas we extract from the Earth originate from the preserved remains of ancient plants and animals, thus coining the term “fossil fuels.” Unfortunately, our exploitation of these resources far exceeds their natural replenishment rate, posing significant concerns for the future.

Contemporary scientific research predominantly supports the biogenic theory, given the substantial and compelling evidence in its favor. In contrast, the abiogenic theory, proposed over a century ago, faces increasing skepticism as modern findings challenge its original principles. This ongoing dialogue underscores the ever-evolving complexity of our understanding of Earth’s geological history and the origins of the invaluable resources we unearth deep within its crust.

What is the Abiotic theory of origin of petroleum 

The abiogenic petroleum origin theory states that natural petroleum comes from deep carbon deposits, possibly dating back to the Earth’s formation. The presence of hydrocarbons throughout the solar system implies that there might be more petroleum on Earth than commonly believed, with carbon-rich fluids migrating upward from the Earth’s mantle. Dmitri Mendeleev (1877), the Russian scientist who created the periodic table of elements, proposed that metallic carbides deep within the Earth reacted with water at high temperatures, producing acetylene (C2H2), which then condensed to form heavier hydrocarbons.

Alexander Kitchka from the Ukrainian National Academy of Sciences boldly suggests that around 60% of the content in all oil might be abiotic in origin, rather than derived from fossil fuels. He advocates for more profound drilling efforts to locate this unconventional oil. Kitchka also posits that oil could potentially exist in various geological structures like volcanic rock or deep-sea thermal vents, which are not currently areas of focus for oil exploration companies.

However, there are challenges with the inorganic hypotheses. Firstly, there’s no direct evidence to confirm whether the organic material in chondritic meteorites originates from an inorganic source or an originally organic parent material. Secondly, field evidence doesn’t support inorganic processes occurring in nature, while there’s increasing evidence for an organic origin. Thirdly, if an inorganic origin were the primary source of hydrocarbons, we would expect substantial hydrocarbon emissions from volcanoes, solidified magma, and other igneous rocks, which is not observed.

Biotic theory 

The biotic or organic theory suggests that petroleum is formed from ancient biological materials left behind by early life. According to this theory, these materials undergo high-temperature processes without oxygen. The biogenic theory is widely accepted among scientists due to strong supporting evidence. This theory posits that the organic matter giving rise to petroleum originated through photosynthesis, the process by which solar energy is captured and stored. It highlights that while sunlight continually transforms into energy on Earth, only a tiny fraction is preserved as organic matter, eventually forming petroleum.

Key to this theory is the composition of source rocks for petroleum, primarily consisting of algae created through photosynthesis. These algae play a pivotal role in creating organic matter, with zooplankton and higher organisms in these ecosystems indirectly reliant on photosynthesis. In essence, the biogenic theory provides a compelling explanation for petroleum’s origins, underpinned by substantial scientific backing.

The traditional perspective on petroleum formation suggests that specific portions of biomass from deceased organisms were buried in sedimentary basins. Over time, these biomass samples underwent diagenesis due to prolonged exposure to microbial decay, increasing temperatures, and pressures. Oxygen-depleted conditions, caused by the depletion of local oxygen levels through biomass decay and sometimes maintained by barriers preventing oxygen recharge, significantly enhance the preservation of fossil organic matter, allowing it to pass into the geosphere.

Endless oil? 

The truth and proof behind petroleum formation within Earth’s methane remains elusive, as neither of the two theories offers conclusive evidence as the sole mechanism. The biotic origin of petroleum raises concerns about depleting oil reserves. At the same time, the abiotic hypothesis suggests nearly limitless oil and gas supplies. These differences give rise to pressing questions regarding energy sustainability.

Considering everything, the biotic origin of petroleum is well-supported by credible evidence and widely embraced in contemporary scientific circles. Despite a few disagreements with the opposing theory, this explanation is commonly acknowledged as the true hypothesis for petroleum’s origin. Scientists find substantial evidence favoring the biotic origin, making it the prevailing and widely accepted explanation, even though it encounters some challenges from the opposing perspective.

If you have any queries or come across suspicious content related to climate change or the environment and want us to verify them, send them to Climate Buddy, our WhatsApp tipline +91 70453 66366.

References:

1. https://twitter.com/robinmonotti/status/1710187559182033270?t=2yL3x6CgULqieadwp2o4bw&s=19
2. https://www.bionity.com/en/encyclopedia/Abiogenic_petroleum_origin.html
3. https://www.forbes.com/2008/11/13/abiotic-oil-supply-energenius08-biz-cz_rl_1113abiotic.html?sh=509247763f9e
4. https://www.dnr.louisiana.gov/assets/TAD/education/BGBB/3/origin.html
5. https://connect.spe.org/blogs/donatien-ishimwe/2014/09/11/origin-and-formation-of-petroleum
6. https://link.springer.com/content/pdf/10.1007/978-3-642-34132-8.pdf
7. https://www.researchgate.net/publication/226441668_The_Origin_of_Petroleum