In this blog post, we will examine the limitations of fossil fuels and the challenges of climate change, and explore the direction of sustainable alternative energy.
Human progress has gone hand in hand with advancements in the quantity and quality of the energy we use. Energy is an essential element for human development. As society transformed from one reliant on human and animal power to one utilizing fossil fuels such as coal and oil, humanity achieved rapid material progress. The use of energy has revolutionized human life, and as a result, social structures and economic systems have also advanced significantly. Fossil fuels currently account for 80% of the world’s energy consumption, making them the very heart that keeps society running. We will now examine in detail the history of fossil fuels—which have contributed to human progress—their specific types, and their resulting social and environmental impacts.
Fossil fuels are divided into three main resources: coal, oil, and natural gas. Each resource has had diverse impacts on human civilization depending on its physical state and method of use. Coal, a solid fossil fuel, is classified into lignite, bituminous coal, and anthracite, and was the first resource humanity actively utilized. The use of coal increased rapidly during the 18th and 19th centuries, particularly driving the Industrial Revolution of the 19th century and laying the foundation for modern industrial society. At that time, coal was abundant and economical, and its higher energy efficiency compared to wood made it a vital energy resource that transcended its role as mere firewood. The thermal energy generated during coal combustion enabled mass production systems, and alongside the development of the steel industry, human technological capabilities achieved remarkable growth. However, the large-scale use of coal led to various environmental problems. The various pollutants and soot produced by coal combustion exacerbated air pollution, revealing both the bright side and the dark side of industrialization.
Liquid petroleum emerged as a substitute for coal after being discovered in large quantities at Spindletop, Texas, in 1901. With the subsequent discovery of numerous large oil fields, petroleum has established itself as the most widely used energy source to this day. The discovery of oil and advancements in refining technology, by the mid-20th century, drove the development of various modes of transportation, such as automobiles, aircraft, and ships. This, coupled with the globalization of the world economy, accelerated the progress of human civilization. Crude oil extracted from underground consists of various hydrocarbons and is converted into various petroleum products, such as gasoline, diesel, and kerosene, through refining. These petroleum products are used as essential resources in nearly every sector of modern society, and their importance is particularly critical in the transportation and industrial sectors.
Natural gas, a gaseous fossil fuel, is a resource often discovered alongside oil. It is characterized as a clean fuel because it emits less carbon dioxide per unit of energy produced compared to oil. Natural gas is widely used as a household energy source and is playing an increasingly important role in power generation. However, because natural gas exists in a gaseous state at room temperature, its storage and transportation involve greater technical challenges than those associated with oil. High-pressure tanks are required to store compressed gas, and the construction of the necessary infrastructure is essential. For these reasons, natural gas is used in relatively smaller quantities compared to oil or coal; however, as concern for environmental protection grows, demand for it is gradually increasing.
Large oil fields have continued to be discovered since the Spindletop discovery, and because oil is more energy-efficient than coal and natural gas, it has remained an essential energy source from the 20th century to the present. Oil has had a significant impact on the global economy and politics, creating an international dynamic in which many countries compete and cooperate to secure energy resources.
In particular, fluctuations in oil prices have a major impact on the global economy, and this has even served as a cause of diplomatic tensions and wars between nations. Half of all petroleum products are consumed by transportation, and this proportion is said to be continuing to rise. This signifies the expansion of transportation infrastructure alongside the development of the automotive industry, enabling the fast and efficient mobility of modern society.
However, although we have long been aware that oil—which occupies such an important place in our society—is a finite resource, we have not been sufficiently concerned about its depletion. The depletion of oil does not mean that the amount available for us to use will completely disappear at a specific point in time; rather, it should be understood to mean that while there will be sufficient quantities for several decades, a point will eventually come when we can no longer obtain the desired amount. These limitations of oil resources have become one of the reasons why humanity must consider future energy sources. Most of the existing large oil fields have already been discovered, and new fields are often too small to be economically viable for extraction. As a result, the reserves of newly discovered oil fields are steadily decreasing, indicating that the depletion of oil is gradually becoming a reality.
Furthermore, carbon dioxide emissions from the combustion of fossil fuels have caused global warming. Climate change poses a serious challenge to humanity, requiring international cooperation and response. Estimates suggest that the economic impact of rising sea levels, more frequent hurricanes and droughts, increased incidence of infectious diseases, and various other climate-related disasters has amounted to hundreds of trillions of dollars over the past century. The effects of climate change extend beyond natural disasters and could escalate into a systemic crisis threatening human survival. Meteorologists warn that if carbon dioxide concentrations continue to rise, a global catastrophe will be inevitable by the end of the 21st century.
We have two solutions to the limits of oil: improving the energy efficiency of existing systems and developing new energy sources. Improving energy efficiency—a method that reduces energy consumption while maximizing the use of existing infrastructure—plays a crucial role as a short-term solution. On the other hand, the development of new energy sources serves as a long-term solution and is essential for humanity to design a sustainable future. Although various research and development efforts are underway for new energy sources such as alternative energy, there are still many technical and economic challenges to completely replace fossil fuels. In this process, various alternative energy sources—such as nuclear power, solar power, wind power, and hydrogen fuel cells—are gaining attention, but they also have several limitations.
Such alternative energy sources often fail to fully replace the advantages of existing fossil fuels. For example, solar power can only generate electricity when the sun is shining, and wind power’s energy output is heavily dependent on wind speed. Additionally, the high initial installation costs of alternative energy facilities create a significant economic burden. Given that over 95% of transportation relies on petroleum products, one solution to address oil depletion is to develop transportation systems powered by energy sources other than petroleum. While hydrogen and electric vehicles have been proposed as solutions to this problem, they still face technical constraints and challenges in infrastructure development. In particular, hydrogen vehicles require significant time and investment before hydrogen production and storage technologies can be commercialized.
Earlier, we examined fossil fuels, their impact on humanity, and the resulting problems and solutions. While fossil fuels have been a vital resource driving human progress, they are now reaching their limits. To prepare for the depletion of fossil fuels and environmental issues, active research and development into alternative energy sources is necessary, and this will be a critical task that determines the future of humanity. If fossil fuels have driven human progress, it is now time for sustainable energy to ensure humanity’s survival.
