A non-renewable resource (also called a finite resource)
is a resource of economic value that cannot be readily replaced by
natural means at a quick enough pace to keep up with consumption. An
example is carbon-based fossil fuel. The original organic matter, with
the aid of heat and pressure, becomes a fuel such as oil or gas. Earth minerals and metal ores, fossil fuels (coal, petroleum, natural gas) and groundwater in certain aquifers are all considered non-renewable resources, though individual elements are always conserved (except in nuclear reactions).
Conversely, resources such as timber (when harvested sustainably) and wind (used to power energy conversion systems) are considered renewable resources, largely because their localized replenishment can occur within time frames meaningful to humans as well.
Earth minerals and metal ores
Earth minerals and metal ores are examples of non-renewable resources. The metals themselves are present in vast amounts in Earth's crust, and their extraction by humans only occurs where they are concentrated by natural geological processes
(such as heat, pressure, organic activity, weathering and other
processes) enough to become economically viable to extract. These
processes generally take from tens of thousands to millions of years,
through plate tectonics, tectonic subsidence and crustal recycling.
The localized deposits of metal ores near the surface which can
be extracted economically by humans are non-renewable in human
time-frames. There are certain rare earth minerals and elements that are more scarce and exhaustible than others. These are in high demand in manufacturing, particularly for the electronics industry.
Fossil fuels
Natural resources such as coal, petroleum (crude oil) and natural gas
take thousands of years to form naturally and cannot be replaced as
fast as they are being consumed. Eventually it is considered that
fossil-based resources will become too costly to harvest and humanity
will need to shift its reliance to other sources of energy such as solar
or wind power, see renewable energy.
An alternative hypothesis is that carbon based fuel is virtually
inexhaustible in human terms, if one includes all sources of
carbon-based energy such as methane hydrates on the sea floor, which are
vastly greater than all other carbon based fossil fuel resources
combined.
These sources of carbon are also considered non-renewable, although
their rate of formation/replenishment on the sea floor is not known.
However their extraction at economically viable costs and rates has yet
to be determined.
At present, the main energy source used by humans is non-renewable fossil fuels. Since the dawn of internal combustion engine
technologies in the 19th century, petroleum and other fossil fuels have
remained in continual demand. As a result, conventional infrastructure and transport
systems, which are fitted to combustion engines, remain prominent
throughout the globe. The continual use of fossil fuels is known to
contribute to global warming and cause more severe climate change.
Nuclear fuels
In 1987, the World Commission on Environment and Development (WCED) an organization set up by but independent from the United Nations classified fission reactors that produce more fissile nuclear fuel than they consume -i.e. breeder reactors, and when it is developed, fusion power, among conventional renewable energy sources, such as solar and falling water. The American Petroleum Institute likewise does not consider conventional nuclear fission as renewable, but that breeder reactor nuclear power fuel is considered renewable and sustainable, before explaining that radioactive waste from used spent fuel rods remains radioactive, and so has to be very carefully stored for up to a thousand years.
With the careful monitoring of radioactive waste products also being
required upon the use of other renewable energy sources, such as geothermal energy.
The use of nuclear technology relying on fission requires Naturally occurring radioactive material as fuel. Uranium, the most common fission fuel, and is present in the ground at relatively low concentrations and mined in 19 countries. This mined uranium is used to fuel energy-generating nuclear reactors with fissionable uranium-235 which generates heat that is ultimately used to power turbines to generate electricity.
As of 2013 only a few kilograms (picture available) of uranium have been extracted from the ocean in pilot programs
and it is also believed that the uranium extracted on an industrial
scale from the seawater would constantly be replenished from uranium leached from the ocean floor, maintaining the seawater concentration at a stable level. In 2014, with the advances made in the efficiency of seawater uranium extraction, a paper in the journal of Marine Science & Engineering suggests that with, light water reactors as its target, the process would be economically competitive if implemented on a large scale.
Nuclear power provides about 6% of the world's energy and 13–14% of the world's electricity. Nuclear energy production is associated with potentially dangerous radioactive contamination as it relies upon unstable elements. In particular, nuclear power facilities produce about 200,000 metric tons of low and intermediate level waste (LILW) and 10,000 metric tons of high level waste (HLW) (including spent fuel designated as waste) each year worldwide.
Issues entirely separate from the question of the sustainability
of nuclear fuel, relate to the use of nuclear fuel and the high-level
radioactive waste the nuclear industry generates that if not properly
contained, is highly hazardous to people and wildlife. The United Nations (UNSCEAR) estimated in 2008 that average annual human radiation exposure includes 0.01 millisievert (mSv) from the legacy of past atmospheric nuclear testing plus the Chernobyl disaster and the nuclear fuel cycle, along with 2.0 mSv from natural radioisotopes and 0.4 mSv from cosmic rays; all exposures vary by location. natural uranium in some inefficient reactor nuclear fuel cycles, becomes part of the nuclear waste "once through"
stream, and in a similar manner to the scenario were this uranium
remained naturally in the ground, this uranium emits various forms of
radiation in a decay chain that has a half-life of about 4.5 billion years, the storage of this unused uranium and the accompanying fission reaction products have raised public concerns about risks of leaks and containment, however the knowledge gained from studying the Natural nuclear fission reactor in Oklo Gabon,
has informed geologists on the proven processes that kept the waste
from this 2 billion year old natural nuclear reactor that operated for
hundreds of thousands of years.
Renewable resources
Natural resources, known as renewable resources, are replaced by natural processes and forces persistent in the natural environment. There are intermittent and reoccurring renewables, and recyclable materials, which are utilized during a cycle across a certain amount of time, and can be harnessed for any number of cycles.
The production of goods and services by manufacturing products in economic systems creates many types of waste during production and after the consumer has made use of it. The material is then either incinerated, buried in a landfill or recycled for reuse. Recycling turns materials of value that would otherwise become waste into valuable resources again.
In the natural environment water, forests, plants and animals are all renewable resources, as long as they are adequately monitored, protected and conserved. Sustainable agriculture is the cultivation of plant and animal materials in a manner that preserves plant and animal ecosystems and that can improve soil health and soil fertility over the long term. The overfishing of the oceans is one example of where an industry practice or method can threaten an ecosystem, endanger species and possibly even determine whether or not a fishery is sustainable for use by humans. An unregulated industry practice or method can lead to a complete resource depletion.
The renewable energy from the sun, wind, wave, biomass and geothermal energies are based on renewable resources. Renewable resources such as the movement of water (hydropower, tidal power and wave power), wind and radiant energy from geothermal heat (used for geothermal power) and solar energy (used for solar power)
are practically infinite and cannot be depleted, unlike their
non-renewable counterparts, which are likely to run out if not used
sparingly.
The potential wave energy on coastlines can provide 1/5 of world
demand. Hydroelectric power can supply 1/3 of our total energy global
needs. Geothermal energy can provide 1.5 more times the energy we need.
There is enough wind to power the planet 30 times over, wind power could
power all of humanity's needs alone. Solar currently supplies only 0.1%
of our world energy needs, but there is enough out there to power
humanity's needs 4,000 times over, the entire global projected energy
demand by 2050.
Renewable energy and energy efficiency are no longer niche sectors
that are promoted only by governments and environmentalists. The
increasing levels of investment and that more of the capital is from
conventional financial actors, both suggest that sustainable energy has
become mainstream and the future of energy production, as non-renewable
resources decline. This is reinforced by climate change concerns, nuclear dangers and accumulating radioactive waste, high oil prices, peak oil and increasing government support for renewable energy. These factors are commercializing renewable energy,
enlarging the market and growing demand, the adoption of new products
to replace obsolete technology and the conversion of existing
infrastructure to a renewable standard.
Economic models
In economics, a non-renewable resource is defined as goods, where greater consumption today implies less consumption tomorrow.David Ricardo
in his early works analysed the pricing of exhaustible resources, where
he argued that the price of a mineral resource should increase over
time. He argued that the spot price is always determined by the mine
with the highest cost of extraction, and mine owners with lower
extraction costs benefit from a differential rent. The first model is
defined by Hotelling's rule, which is a 1931 economic model of non-renewable resource management by Harold Hotelling.
It shows that efficient exploitation of a nonrenewable and
nonaugmentable resource would, under otherwise stable conditions, lead
to a depletion of the resource. The rule states that this would lead to a net price or "Hotelling rent" for it that rose annually at a rate equal to the rate of interest, reflecting the increasing scarcity of the resources.
The Hartwick's rule provides an important result about the sustainability of welfare in an economy that uses non-renewable source.