Why Are Non-Renewable Energy Resources Considered Limited?
Definition of Non-Renewable Resources
Non-renewable resources are materials that cannot be easily replenished by natural processes. The most important non-renewable resources are fossil fuels – oil, natural gas, and coal. Fossil fuels formed from the remains of plants and animals that lived millions of years ago and were gradually buried under layers of rock. Under intense heat and pressure over millions of years, the organic material transformed into fossil fuels.
Once fossil fuel reserves are depleted, they cannot be renewed on a human timescale. It took hundreds of millions of years for fossil fuels to form, so once used up, they are essentially gone. That makes fossil fuels a finite resource from a human perspective.
Formation Process
Non-renewable resources such as oil, natural gas, and coal are formed by natural processes that occur over millions of years. These resources are produced from the decomposition and transformation of organic matter, through high temperatures and pressures beneath the Earth’s surface over long geological timespans.
For example, oil and natural gas originate from ancient organic materials like microscopic plankton and plant matter that lived millions of years ago. When these organisms died, they sank to the seafloor and were gradually buried by sediment. As they got buried deeper, the increase in temperature and pressure turned the organic matter into hydrocarbons like oil and gas.
Similarly, coal forms from the remains of trees, ferns and other plants that lived 300-400 million years ago. These plant remains accumulated in swamps and peat bogs, before being buried and transformed into coal seams from the pressure and heat deep underground over millions of years.
The long timescales and specific conditions required to form these resources mean they are produced far more slowly than the rate at which they are extracted and consumed. This makes them finite resources that cannot be readily replenished on human timescales.
Finite in Supply
Non-renewable energy resources like oil, natural gas, and coal are finite in supply because they formed from the remains of plants and animals that lived hundreds of millions of years ago. There are limited deposits of these fossil fuels around the world that accumulated under specific conditions over vast periods of geological time.
Oil, for example, was formed from the preserved remains of tiny marine plants and animals that lived in ancient seas. Over millions of years, the organic material was buried under successive layers of sand and silt. The resulting heat and pressure transformed the organic compounds into liquid hydrocarbons that accumulated in underground reservoirs of porous rock like sandstone or limestone.
Natural gas formed in a similar way, while coal was created from the buildup of plant material in swamp environments that were eventually buried and compressed into solid carbon deposits.
Since these fossil fuels require such unique conditions to form, deposits are not evenly distributed around the world. Once the limited reserves are used up, there will be no more. New reserves cannot be readily created on human timescales.
Extraction Challenges
As non-renewable resources like oil, natural gas, and coal are extracted over time, the remaining reserves become more difficult and expensive to access. The easiest deposits are extracted first, leaving resources that are buried deeper underground, located in more remote areas, offshore, or in smaller concentrations. Advanced methods like hydraulic fracturing, offshore drilling, oil sands extraction, and mountaintop removal mining allow continued extraction, but require more energy, complex infrastructure, higher costs, and greater environmental impacts. The declining energy return on energy invested makes extraction less efficient. Even renewable resources face extraction challenges over time, as the best locations are utilized first before moving to less optimal ones.
Rate of Consumption
Fossil fuels like oil, coal, and natural gas are being burned at an astounding rate to produce energy and power transportation around the world. According to the U.S. Energy Information Administration, in 2019 over 80% of the world’s energy came from fossil fuels. The global demand for oil averages over 90 million barrels per day. At this rate, known global oil reserves are projected to run out in around 50 years. Coal and natural gas are also being consumed rapidly, especially for electricity generation. The world relies heavily on non-renewable resources to power homes, businesses, vehicles and more. As developing countries continue to grow, their energy demands are skyrocketing too. Unless we curb our fossil fuel dependence, non-renewable reserves will be drained faster than new ones can be discovered.
Developing Countries
Many developing countries are experiencing rapid economic growth and industrialization. This leads to increasing energy demand, as these countries build infrastructure, factories, transportation systems and modernize cities. Most developing countries rely heavily on fossil fuels like coal and oil to meet their energy needs.
For example, countries like China and India have seen energy demand grow exponentially in recent decades. China is the world’s largest energy consumer today. India is projected to have the largest increase in energy demand by 2040. Both countries rely on coal for a majority of their electricity generation.
Developing countries face a dilemma – they need ample energy to support economic growth and improve quality of life, but increased fossil fuel use also leads to more carbon emissions and environmental issues. Many developing countries argue that industrialized nations should shoulder more responsibility for reducing emissions, since they historically account for most emissions.
Providing energy access to the billions still lacking modern energy services, while transitioning to cleaner sources, remains a huge challenge for developing countries.
Alternatives
There are several renewable energy alternatives that can replace non-renewable resources.
Solar power harnesses energy from the sun and converts it into electricity. Solar panels can be installed on rooftops or large solar farms can generate utility-scale solar power. Solar energy has become dramatically cheaper over the past decade making it competitive with fossil fuels.
Wind power uses large wind turbines to generate electricity. Wind farms can be built onshore or offshore in windy locations. Wind power capacity and generation continues to expand rapidly around the world.
Geothermal energy taps into underground reservoirs of steam or hot water which can be used to generate electricity. Geothermal plants provide consistent clean power and have a small land footprint.
Other renewable sources like hydroelectric power and biomass energy can also substitute for non-renewables. The key benefit of renewables is that they are unlimited and sustainable if properly managed.
Environmental Impact
The use of non-renewable energy sources like coal, oil and natural gas has a major impact on the environment. Burning these fossil fuels releases a number of harmful pollutants and greenhouse gases like carbon dioxide and methane into the atmosphere.
Increased greenhouse gas emissions from burning fossil fuels is the primary driver of global climate change. The greenhouse gases trap heat in the atmosphere, causing worldwide temperatures to rise. This leads to melting glaciers, rising sea levels, more extreme weather events like droughts, floods and hurricanes, and overall disruption of ecosystems.
Extracting and transporting fossil fuels also carries environmental risks like oil spills. Coal mining techniques like mountaintop removal can lead to deforestation and the destruction of habitats. Nuclear power creates radioactive waste that must be properly disposed of.
Transitioning to renewable energy sources like solar, wind and hydro power that do not release greenhouse gases can help mitigate the environmental damage caused by our reliance on non-renewable sources and combat climate change.
Peak Production
Non-renewable energy resources like oil, natural gas, and coal have a point where their maximum rate of production is reached. This point is known as peak production or peak output. After this peak, production begins to decline as reserves get depleted.
Peak production occurs because non-renewable resources are finite. Extraction follows a bell-shaped curve, with output rising to a peak when approximately half the recoverable reserves have been depleted, and then declining as the remaining reserves get exhausted. The timing of peak production depends on the size of recoverable reserves and the rate of extraction.
Predicting peak production is challenging due to uncertainties around reserve estimates and future demand. However, geologists estimate that peak oil production could occur in the near future. Natural gas and coal may reach their peaks later this century if consumption continues rising exponentially.
After peak production, output falls but demand does not, leading to scarcity and rising prices. The decline can be sudden if discovery and investment in new reserves does not keep pace with depletion. Understanding peak production timing allows planning for transitioning to renewable energy alternatives before scarcity causes massive disruption.
Depletion Timescales
Most non-renewable energy resources face eventual depletion due to their finite supply and continuous consumption. However, projected exhaustion dates vary greatly depending on the resource.
Fossil fuels like oil and natural gas may run out within the next 50-100 years based on current reserves and usage rates. Coal is expected to be available for up to 150 years. Uranium for nuclear power could be depleted within 50-70 years.
These timescales are constantly being revised as new deposits are discovered and consumption rates change. Technologies like fracking and deep sea drilling can also extend fossil fuel availability. Regardless, non-renewables face depletion much faster than their formation, which took hundreds of millions of years.
With global energy demand rising, especially among developing nations, depletion estimates are shrinking. This highlights the need to transition to renewable energy alternatives before non-renewables are exhausted.
