Renewable vs Nonrenewable Natural Resources

Natural resources are materials and energy sources from the environment that people use; renewable resources can be replaced by natural processes at a rate comparable to their use (such as sunlight, wind, water and forests), while nonrenewable resources exist in a fixed amount or are replaced so slowly that they are effectively used up (such as fossil fuels and minerals). In brief: renewable resources can be used indefinitely if they are used at or below their rate of renewal; they become depleted if overexploited, like fish stocks or forests. Nonrenewable resources are finite, and their lifetime depends on the size of the reserves and on the rate of consumption. Some resources, like metals, are nonrenewable but can be recycled.

The difference between the two types is the foundation of resource management and sustainability. This guide defines natural resources and the two categories, explains the idea of sustainable yield and reserve lifetime, compares the types in a table, works through numerical examples, outlines the history of resource use and corrects common mistakes.

What are natural resources?

A natural resource is anything from nature that people use to meet their needs: land, water, air, soil, forests, fish, minerals and energy sources. Things become resources when people have the knowledge and technology to use them and when there is a demand: uranium was not a resource before nuclear technology. Resources can be classified in several ways: by origin (biotic from living things, like timber and fish, and abiotic like minerals and water), by renewability (renewable or nonrenewable), by stage of development (potential, actual, reserves) and by ownership (individual, national or shared “global commons”, such as the atmosphere and the high seas). The distribution of resources is uneven, which influences the economies, trade and politics of countries.

What are renewable resources?

Renewable resources are replaced by natural processes within a human time scale. There are two groups. Flow (inexhaustible) resources are not reduced by use: solar radiation, wind, tides, waves and geothermal heat. Stock (renewable) resources can be depleted if used faster than they regenerate: forests, fish, fresh water, soil fertility and wildlife. Their sustainable use depends on the sustainable yield, the amount that can be harvested each year without reducing the stock: for a forest it is the annual growth. Overexploitation can cause collapse, as in the cod fishery off Newfoundland in the early 1990s. Renewable does not mean harmless: hydropower dams and biofuel crops have environmental effects, and fertile soil takes centuries to form.

What are nonrenewable resources?

Nonrenewable resources are formed over geological time (millions of years), so on a human scale the amount is fixed. They include fossil fuels (coal, oil and natural gas, formed from ancient organic matter), metal ores (iron, copper, aluminum, gold) and nonmetallic minerals (sand, gravel, limestone, phosphate, salt), and the nuclear fuel uranium. Resources are described as reserves (known and economically recoverable with current technology) and resources (the total amount including those not yet discovered or not yet economical). Reserves increase with new discoveries, better technology and higher prices, so the “years left” is not fixed. Some nonrenewables are reusable: metals and glass can be recycled many times, whereas the energy in fossil fuels is lost when they are burned, and they add carbon dioxide to the atmosphere.

Renewable and nonrenewable resources compared

Worked example: yield and lifetime

1. Sustainable yield (hypothetical forest): a forest of 10,000 hectares grows an average of 3 m³ of wood per hectare per year. The sustainable annual harvest is 10,000 × 3 = 30,000 m³.
2. Overharvest: if 40,000 m³ is cut each year, the stock falls by 40,000 − 30,000 = 10,000 m³ a year. With a standing stock of 600,000 m³, it would be exhausted after 600,000 ÷ 10,000 = 60 years (ignoring that growth falls as the forest shrinks).
3. Reserve lifetime (R/P ratio): a mineral has reserves of 1,000 million tonnes, and annual consumption is 25 million tonnes. The reserves-to-production ratio is 1,000 ÷ 25 = 40 years at a constant consumption.
4. With growing consumption: if consumption grows by 2 percent a year, the lifetime n satisfies n = ln(1 + R × r ÷ C) ÷ r = ln(1 + 1,000 × 0.02 ÷ 25) ÷ 0.02 = ln(1.8) ÷ 0.02 = 0.588 ÷ 0.02 = 29.4 years. Growth shortens the lifetime from 40 to about 29 years.
5. Recycling: if 50 percent of the consumption of 25 million tonnes could be supplied by recycling, the demand for new material falls to 12.5 million tonnes a year, and the constant-rate lifetime doubles to 1,000 ÷ 12.5 = 80 years.

How has resource use changed?

Early societies relied on renewable biomass: wood, plants, animals and muscle power, wind and water. The use of coal in the Industrial Revolution from the 18th century started the age of fossil fuels, and oil and natural gas became dominant in the 20th century. The use of materials grew greatly in the same period: the extraction of sand, gravel, metals and fossil fuels increased many times. Concerns about limits were raised by Thomas Malthus (1798), William Stanley Jevons on coal (1865), and the Club of Rome’s report The Limits to Growth (1972). Today, the cost of renewable energy has fallen, and the focus is on the transition from fossil fuels and on a circular economy.

Which mistakes are common?

Mistake 1: Thinking that renewable resources cannot be depleted

Stock resources such as forests, fish and groundwater can be used up if they are harvested faster than they regrow.

Mistake 2: Treating the reserve lifetime as a fixed date

Reserves change with discoveries, prices and technology, and consumption rates change.

Mistake 3: Assuming that all nonrenewable resources are lost after use

Metals and many minerals can be recycled. Fossil fuels cannot be reused after burning.

Mistake 4: Assuming that renewable energy has no environmental effects

Dams, wind farms, solar plants and biofuel crops all use land and affect ecosystems, though usually with lower emissions.