What are fossil fuels?
Fossil fuels are energy sources derived from the remains of ancient plants and animals. These remains were hidden under sediment and rock for millions of years. Fossil fuels contain carbon and hydrogen, which can be burned to make heat and electricity. Humans can’t replenish fossil fuels, so they’re non-renewable and cause climate change and greenhouse gas emissions.
A. Definition of fossil fuels
Coal, oil, and natural gas are the main hydrocarbons in fossil fuels. These hydrocarbons are produced by the breakdown and modification of organic matter in the Earth’s crust at high pressures and temperatures. Fossil fuels are the primary energy source for industrialized nations, but they also have significant negative effects on the environment and society.
B. Fossil fuel types
Fossil fuels include coal, oil, and natural gas. Each type has different characteristics, uses, advantages, and disadvantages.
- The elements carbon, hydrogen, oxygen, nitrogen, and sulfur make up the solid substance known as coal. Anthracite, bituminous, lignite, and peat coal are the four categories into which coal is ranked according to the amount of carbon and heating value. Coal is used for electricity generation, steel production, and cement manufacturing.
- Oil is a liquid mixture of hydrocarbons that can be refined into various products such as gasoline, diesel, kerosene, jet fuel, lubricants, plastics, and asphalt. Oil is formed from the remains of marine organisms that accumulated in sedimentary basins and were subjected to heat and pressure over millions of years. Oil is used for transportation, heating, and industrial processes.
- Methane makes up the majority of the gaseous mixture of hydrocarbons known as natural gas. Traditional reservoirs connected to oil deposits or unconventional sources like shale gas and tight gas can contain natural gas. Advanced extraction methods are required for these sources. Natural gas is used for electricity generation, heating, cooking, and fertilizing.
C. Formation of fossil fuels
Fossil fuels are formed through a complex process that involves biological, chemical, and physical factors. Fossil fuel formation involves:
- Organic matter accumulation: Plants and animals die and their remains accumulate in aquatic or terrestrial environments where they are protected from decay by oxygen deprivation or rapid burial.
- Diagenesis: Organic matter undergoes physical and chemical changes under moderate temperature and pressure conditions to form peat (for coal), kerogen (for oil), or methane (for natural gas).
- Catagenesis: Peat or kerogen undergoes further thermal cracking and dehydration under high temperature and pressure conditions to form coal or oil respectively.
- Metagenesis: Coal or oil undergoes further thermal alteration under extreme temperature and pressure conditions to form anthracite (for coal) or natural gas (for oil).
Fossil fuels are formed in millions to hundreds of millions of years. This depends on the type of organic matter, the depth of burial, the temperature gradient, tectonic activity, and water availability.
Why are fossil fuels exhaustible?
Natural resources known as fossil fuels were created over millions of years from ancient plants and animals. The majority of the energy we use today for electricity, transportation, and industry comes from these sources, which also include coal, oil, and natural gas. Since fossil fuels cannot be quickly replenished, they are not renewable. In fact, fossil fuels are exhaustible, which means that if we keep using them at our current rate, they will eventually run out. Fossil fuels are exhaustible for four main reasons:
A. Limited fossil fuel availability
Fossil fuel distribution is uneven worldwide. There are more reserves in some places than in others, and some fossil fuels are more common. The largest coal reserves, for instance, are in China, while the largest oil reserves are in the Middle East. This implies that some nations must import fossil fuels from other nations, which may raise transportation prices and harm the environment. In addition, some fossil fuels, like those found in the deep ocean or the Arctic, are more challenging to access than others. This means that extracting them will cost more and have a greater negative impact on the environment. This is because it requires advanced technology and investment.
B. Slow rate of fossil fuel formation
According to estimates, coal takes 300 million years to form from plant matter. Natural gas develops from plant and animal matter in about 50 million years and oil from marine organisms takes about 90 million years to form. Therefore, the quantity of fossil fuels we have today is the end result of a protracted geological process that began before the dinosaur era. This implies that even if we try to mimic natural conditions, we cannot produce more fossil fuel quickly.
C. High consumption rate of fossil fuels
Human activities are powered by fossil fuels. The International Energy Agency (IEA) estimates that about 80% of the world’s energy supply will come from fossil fuels in 2019. Due to urbanization, economic growth, and population growth, energy demand has increased over time. This indicates that we are using fossil fuels at a higher rate than ever before and faster than nature can replace them. The IEA predicts that in 2019, the world will burn about 1.6 million kilograms of coal per second. This is 11.7 billion tonnes of oil equivalent (toe) of fossil fuels.
D. Unsustainable extraction and production of fossil fuels
Fossil fuels harm the environment and human health, which are also finite and exhaustible. Drilling, mining, refining, and transportation are just a few of the tasks involved in fossil fuel extraction and production. Land degradation, water pollution, air pollution, and greenhouse gas emissions can all be affected by these activities. Additionally, these activities run the risk of causing accidents like explosions, gas leaks, and oil spills. These accidents could have catastrophic effects on local communities and wildlife. Burning fossil fuels also contributes to global warming and climate change by releasing pollutants into the atmosphere, such as carbon dioxide (CO2).
Due to their limited availability, slow formation, high consumption rates, and unsustainable extraction and production processes, fossil fuels are finite and will eventually run out. Fossil fuels are non-renewable and unfriendly to the environmental source of energy that, if our habits and preferences do not change, will eventually run out. Looking into renewable, efficient, and clean alternative energy sources like solar, wind, and hydropower is worthwhile.