In this blog post, we will examine how fossil fuels—which have driven human life and industrial development—were formed and utilized, as well as their advantages and limitations, the environmental issues they pose, and the need for alternative energy sources.
Humanity’s Need for Energy and Fossil Fuels
Physically speaking, “energy” refers to the ability to perform work. To lead more convenient lives, humanity needed tools to perform tasks on its behalf, and these tools required “energy” to operate. Following the Industrial Revolution, as large-scale energy supply systems—including fossil fuels—began to develop in earnest, humanity achieved remarkable industrial and technological progress. Even today, fossil fuels remain a vital energy source, accounting for approximately 80% of global energy demand.
Fossil energy refers to fuels formed when organic matter from dead plants and animals is buried in geological strata and subjected to heat and pressure over long periods of time. It is fascinating to consider how energy can be derived from dead plants and animals. Most living organisms undergo cellular respiration, a process in which they convert high-energy organic matter into substances with relatively lower energy levels through a series of steps. By utilizing the energy generated during this process to perform tasks such as maintaining order within the cell, organisms are able to sustain their life activities. Fossil fuels, formed through long geological processes after organisms have died, also originate from organic matter that stores chemical energy. This is because the bodies of plants and animals originally contained high-energy organic matter produced using solar energy. Therefore, extracting energy from fossil fuels and using it for our purposes can be viewed as connected to the process by which organisms extract energy from their own organic matter for vital functions, particularly in terms of energy storage and release.
So, how are these high-energy organic compounds produced? To answer this question first, such high-energy organic compounds are produced through “photosynthesis,” a process in which the primary producers of the Earth’s ecosystem absorb solar energy and store it in organic matter. Plants use light energy to convert carbon dioxide and water—which are in a relatively low chemical energy state—into organic matter, producing energy-storage compounds such as glucose in the process. In other words, plants use solar energy to accumulate high-energy organic matter within their bodies, and animals can accumulate organic matter in their bodies by consuming these plants or other animals. The fossil fuels we use were formed from the organic matter of these organisms over a long period of geological transformation; therefore, if we trace the origin of fossil fuels back far enough, we can say they are ultimately connected to solar energy.
Why have fossil fuels been used for so long?
There are several reasons why fossil fuels have accounted for a large proportion of humanity’s energy needs. First, fossil fuels have a high energy density, and technologies to utilize them efficiently have been developing for a long time. Although the energy extracted from fossil fuels was not utilized efficiently from the very beginning, the efficiency of converting energy into useful forms has greatly improved through advancements in various processes and mechanical technologies, such as steam engines, internal combustion engines, and power generation facilities. Behind these advancements lay developments in thermodynamics, chemical engineering, and mechanical engineering. It is no exaggeration to say that the development of science and technology since the Industrial Revolution has been closely linked to humanity’s demand to extract more useful energy from fossil fuels and apply it to industry and daily life.
Second, fossil fuels have long been in forms that are relatively convenient for large-scale storage and transportation. Since coal is a solid and oil is a liquid, they can be stored and transported in large quantities provided the appropriate facilities and conditions are in place. Natural gas also has an established infrastructure that allows for large-scale transportation through technologies such as compression and liquefaction. In contrast, while hydrogen has a very high energy content per unit mass, its energy content per unit volume is low; therefore, it must be handled in forms such as high-pressure gas or cryogenic liquid for storage and transportation, and technical and economic challenges exist even during the storage process.
Therefore, rather than simply defining hydrogen as an “unstable energy source due to the risk of explosion,” it is more appropriate to view it as an energy carrier for which storage and transportation technologies are critical, given its high flammability and low volumetric energy density. Similarly, it is difficult to describe nuclear energy as an energy source that explodes simply because uranium itself is unstable. The reactors in nuclear power plants cannot explode in the same way as nuclear weapons, and nuclear power generation involves separate safety issues, such as the management of radioactive materials and radioactive waste, as well as preparedness for the possibility of severe accidents.
Due to these advantages, fossil fuels still account for a large proportion of humanity’s energy supply; however, problems arise because fossil fuels are finite resources that regenerate very slowly. Some might argue that since fossil fuels are formed from the remains of plants and animals, they are a continuously replenished resource because plants and animals are still dying somewhere. However, while the transformation of plant and animal remains into fossil fuels generally requires a very long geological time, modern humanity is consuming fossil fuels at a very rapid pace; therefore, fossil fuels are classified as effectively non-renewable resources. They are being consumed at a rate far faster than the amount newly formed each day. Consequently, if current large-scale consumption continues, fossil fuels will gradually require more resources and advanced technology for extraction and production; in the long term, it will be difficult to sustain a model where humanity’s energy needs rely solely on fossil fuels.
What are the implications of fossil fuel prices for the international community?
The finite nature of fossil fuels can lead to problems such as energy price volatility and supply instability. In the past, as oil prices rose over extended periods, forecasts were repeatedly made that oil prices would increase several times over current levels within the next few decades. However, actual oil prices are not determined solely by the depletion of reserves. A complex interplay of various factors is at work, including oil production and consumption, the international political landscape, policies of oil-producing countries, technological advancements, economic conditions, inventory levels, and the adoption of alternative energy sources. Therefore, forecasts that categorically assert oil prices will rise by a specific multiple in a few years or decades from now are difficult to maintain as accurate at this point in time. Rising fossil fuel prices can also affect the comfort of people’s daily lives. If fossil fuels become more expensive, the operating costs of transportation modes—such as automobiles, aircraft, and ships—will rise, placing a burden on the movement of people and goods. Furthermore, since electricity is often generated using fossil fuels, fluctuations in fossil fuel prices can also affect electricity rates and costs across the entire industrial sector. However, as various power generation sources—such as solar, wind, nuclear, and hydroelectric power—expand, the structure of electricity production, which once relied solely on fossil fuels, is gradually changing. Therefore, it is more appropriate to understand that the depletion or supply instability of fossil fuels does not necessarily mean an immediate halt to all technologies of modern civilization, but rather that it could lead to significant costs and structural changes in industries and areas of daily life that are highly dependent on fossil fuels.
Since fossil fuels—which are so crucial—are not evenly distributed across the globe, this gives rise to serious problems. Countries in the Middle East, where relatively large quantities of oil and natural gas are produced, have long wielded considerable influence in the global energy market. Changes in the production policies and export volumes of oil-producing nations can affect international oil prices, and fluctuations in oil prices become a key factor destabilizing the global economy. In severe cases, a sharp rise in energy costs can increase production costs for businesses and threaten economic growth. The Organization of the Petroleum Exporting Countries (OPEC) was established to alleviate this instability in the international oil market and coordinate the oil policies of oil-producing countries; however, even so, the influence that major oil-producing countries wield in the international community remains significant. Consequently, changes in production levels and policies among major oil-producing countries affect not only the economies of nations around the world but also the daily lives of individuals worldwide.
The uneven distribution of fossil fuels also serves as a source of conflict among nations. Since countries that possess regions rich in fossil fuels may have conflicting interests with other nations regarding the rights to develop those resources, disputes over resources and territory have arisen in various regions. A recent example is the territorial dispute over Dokdo between South Korea and Japan. While the Dokdo issue involves complex factors—including historical, legal, and diplomatic considerations—it is important to exercise caution when asserting that the abundant deposits of fossil fuels and natural gas around Dokdo serve as a key motive for Japan’s territorial claim. Although the potential for resource development in the waters surrounding Dokdo has been discussed, there is insufficient evidence to conclusively determine that this is the core cause of the territorial dispute. Another example is the “Iraq War” of 2003, when the United States invaded Iraq. The official justifications for this war included Iraq’s possession of weapons of mass destruction and security threats; however, since no such weapons were subsequently found, debates over the war’s legitimacy and underlying motives have persisted. While some analyses suggest that Iraq’s vast oil reserves and energy security in the Middle East were key geopolitical factors that drew the attention of the United States and the international community to Iraq, it is not appropriate to attribute the cause of the war solely to oil.
What impact does fossil energy have on the environment?
In addition to problems arising from these quantitative limitations, fossil energy causes environmental pollution. The extraction, transportation, and combustion of fossil fuels release various air pollutants and greenhouse gases, which can adversely affect the environment and human health. Exhaust gases from automobile tailpipes can contain various air pollutants, including substances that contribute to the formation of nitrogen oxides and fine particulate matter; when air pollution reaches severe levels, it can adversely affect respiratory and cardiovascular health. Furthermore, carbon dioxide—a primary greenhouse gas produced during the combustion of fossil fuels—affects the Earth’s energy balance. Greenhouse gases partially inhibit the escape of thermal energy emitted by the Earth into space, thereby raising the Earth’s average temperature; the increased concentration of greenhouse gases resulting from human use of fossil fuels is the primary cause of current global warming. The rise in the Earth’s average temperature is causing various environmental changes, such as abnormal weather patterns, the retreat of glaciers and ice sheets, and rising sea levels, all of which are having serious impacts on human society and ecosystems.
Despite the high energy density of fossil fuels and the already highly advanced technologies for their processing and utilization, humanity is focusing its efforts on developing new alternative and renewable energy sources due to these drawbacks. While the scope of the terms “alternative energy” or “clean energy” may vary depending on the era and policy, they generally refer to the direction of developing and utilizing energy sources that are renewable or that can meet humanity’s energy needs while reducing emissions of greenhouse gases and air pollutants. Solar, wind, hydro, geothermal, nuclear, and hydrogen energy are being utilized or researched as alternatives to fossil fuels. Each of these energy sources has its own advantages and limitations, and it is difficult to evaluate them solely on the basis that their energy efficiency is lower than that of fossil fuels. For example, while solar and wind energy have the advantage of being inexhaustible resources, their power generation varies depending on weather and time of day, necessitating complementary power grids and storage systems.
It is more accurate to view hydrogen not as an energy source but as an energy carrier that stores and transports other forms of energy; therefore, the efficiency and costs of its production, storage, and transportation must be considered together.
Ultimately, the reason humanity has relied on fossil fuels is not simply because they contain a large amount of energy. It is because, through technology and infrastructure accumulated over a long period, we have been able to extract, transport, store, and convert fossil fuels into energy on a large scale. However, fossil fuels are finite resources and have fundamental limitations, as their use generates greenhouse gases and air pollutants. For this reason, humanity is developing various energy technologies that can reduce environmental burdens and energy security concerns while maintaining the advantages of fossil fuels; in fact, technologies such as solar power, wind power, nuclear power, electric vehicles, and hydrogen are expanding rapidly. According to the International Energy Agency (IEA), fossil fuels accounted for approximately 80% of global energy demand in 2023; however, a scenario is projected in which demand for oil, natural gas, and coal will each peak at different rates before declining. Therefore, the upcoming energy transition is unlikely to involve the overnight disappearance of fossil fuels; rather, it is highly likely to be a long-term process of structural change, in which new energy sources and technologies are gradually integrated into the existing fossil-fuel-centric energy system.
