- LIMITED (FINITE) RESOURCES are resources that only exist in a finite supply, so we could run out of them.
Land, fresh water, mineral resources, and fossil fuels are the most important kinds of finite resources.
Several additional resources become limited if poorly managed, or if the human population increases beyond the Earth's habitable limit or "carrying capacity".
- LAND (for Agriculture, or for Human Habitation):
Land in a finite resource. Growing human populations reqjuire more and more land. We may soon run out.
Destruction of forests and other habitats all over the world is one unfortunate consequence of overpopulation and increasing land use.
One possible solution is to get people to eat more plant-based foods. Each acre of land can support the food needs of many more people
(almost ten times as many)
if those people eat mostly plant foods instead of beef and other animal foods.
- FRESH WATER is also a limited resource. It is renewable, but increasing human population is quickly reaching the point
where there may not be enough safe water for drinking or for irrigation of crops everywhere on the planet.
- MINERAL RESOURCES:
Gold and silver are considered precious because their quantity is small. We have always known this.
Other metals exist in larger quantities, but their supply is limited, not inexhaustible:
- Native elements: These metals sometimes occur chemically uncombined, making then simple to extract: gold, silver, copper
- Sulfides: These metals are often combined with sulfur and are easily extracted with only moderate heat: copper, zinc, nickel, tin
- Oxides: A wide variety of metals are found as oxides, including iron, cobalt, manganese, and aluminum.
A good deal of energy (heat or electricity) is required to extract these metals from their ores.
- Carbonates: Calcium and magnesium are commonly found as carbonates.
Calcium carbonate (marble, limestone) is an important building material, and other carbonates are occasionally used instead.
Calcium carbonate can also be roasted and converted into lime (calcium oxide) for use in cement, plaster, and mortar.
- Sulfates: Calcium sulfate (gypsum) and magnesium sulfate (epsom salts) are commercially important in their naturally occurring form.
- Nitrates, phosphates: Several nitrates and phosphates are used as fertilizers.
- FOSSIL FUELS:
Coal is the fossil fuel that has been in use the longest, but the supply is finite.
New coal deposits ar becoming harder and harder
to find and more expensive to extract from deeper underground.
Mining coal is often dangerous work: many miners die from underground
accidents; many more die later on from "Black lung disease" (pneumoconiosis).
Burning coal also causes many forms of pollution, including coal dust (soot), acid rain, carbon dioxide, and many cancer-causing products (carcinogens).
Petroleum (Oil) is currently the fossil fuel that is used the most. Our planet's supply of oil is large but finite.
The largest crude oil deposits are found in the Middle East, in the Gulf Coast region of the United States, and in Venezuela.
Crude oil must be shipped by pipeline or tranker to a refinery for processing into useful fuel products, lubricants, and chemical products.
From the refinery, oil is transported by pipeline or tanker to its destination.
Oil spills and similar accidents occur during transportation.
Hydraulic fracturing ("Fracking") is used to extract hard-to-get petroleum from oil shales. The process uses lots of water and chemicals,
and it leaves behind many
toxic wastes that pollute local groundwater supplies, so there is a lot of opposition to it from people living nearby.
In the United States, hydraulic fracturing has made much more oil available than was previously available, so that the United States
is now a net exporter of oil (we used to be a net importer, mostly from the Middle East and Venezuela).
Natural gas (methane) usually occurs wherever petroleum occurs, and more is generated from petroleum refining.
Natural gan can easily be shipped by pipeline. It burns much cleaner than most other fuels.
Leaks and accidental releases are pollution problems that contribute to global warming and climate change.
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