What Are Earth’s Natural Resources?
Natural resources are often in the news and usually within the context of their depletion and/or conservation, but what are natural resources? Usually, when natural resources are being discussed, the topic is commodities. Natural resources refer to the minerals, oil and gas reserves of the planet. Since the quantities of coal, oil and gas, etc. that mankind has been exploiting, at an ever increasing rate since the industrial revolution, are fixed, they will run out at some date in the future: the reserves are finite.
Non-renewable Natural Resources
The non-renewable natural resources of the planet can be broken down into two groups. The natural resources of organic origin include things such as coal, oil and gas, and peat. Coal, oil and gas are the end products of the decay of living things, produced thousands of years after their death by pressure and chemistry. These resources are known collectively as “fossil fuels". While the (fallen) trees that eventually became coal and the organisms whose dead bodies produced crude oil are still present on Earth, the time taken for these natural resources to regenerate themselves is so long (millennia) that they must be considered as an exhaustible resource.
In the 1970s, it was predicted that all of the world’s crude oil reserves would have been consumed by the year 2000. Fortunately, this prediction proved to be overly pessimistic because crude oil not only provides us with fuel and lubricants for vehicles, but almost all of the plastics we rely on , as well as paints, resins, fabrics, chemicals, dyes, films and many other things.
Despite man’s seemingly insatiable demand for crude oil, productivity has been able to keep up. New oilfields have been discovered and brought into production and developments in exploitation technology have meant that previously inaccessible reserves can be tapped and existing reserves have been more efficiently exploited. However, there is a limited quantity of crude oil on the planet and it is a non-renewable natural resource that will eventually run out.
The second group of non-renewable natural resources are the minerals and ores. The minerals and ores were laid down when the planet formed and many exist in great abundance, however, their supply is fixed. Examples of these natural resources include iron ore, bauxite (the source of aluminum), quartz sand (silicon dioxide), gold, diamonds, slate, granite, etc. Some of these have ores been exploited since man’s earliest history (e.g. the Iron Age). Equally the use of gold and precious stones can be dated back to antiquity. Modern man uses ores and minerals across a vast range of activities, from construction to space exploration. In contrast to the fossil fuels, these resources do not get consumed as such; with the exception of a tiny amount used in space exploration, all of the ores and minerals are still on Earth although they will have undergone extensive alterations (chemical and physical) from their native (i.e. as dug out of the ground) state to the artifacts that they are used in. The steel that is used to make a car, for instance, starts its life as iron ore. The ore is crushed and fired, win iron metal resulting from it. The iron is then smelted with coke at high temperatures and alloyed with selected other metals to give it its desired properties (luster, resistance to corrosion, malleability, etc.) and made into steel from which car parts are made.
Renewable Natural Resources
The other class of natural resources is renewable resources. In general, this group refers to things that can be grown, harvested and then replaced – for example, wood is an illustration of a renewable resource. Trees can be cultivated, allowed to grow to commercial maturity, then are harvested to produce a range of products ranging from timber for construction to paper products made from wood pulp. Once the forest has been felled, new trees are planted for a future crop – this is an example of sustainable management of a natural resource. Another important renewable natural resource is fresh water – without it life on Earth would be impossible. Water cycles from rain clouds, through rivers and lakes to the oceans; seawater evaporates to form clouds and the cycle is completed.
In terms of renewable (natural or so-called “green") energy resources, much interest is placed on hydro-electric plants, estuarine barrages, wave power, solar power and wind power. With the exception of solar power, which produces electricity directly via the photo-electric effect, the others use mechanical energy from the resource to turn a turbine whereby a coil is rotated within a magnetic filed, producing energy.
Now that you have learned what natural resources are and how they are classified, you may now have more of an appreciation for their uses, allowing you to further your efforts to sustain them.