Natural resources are materials found on Earth that are very important for humans. Some of these materials are air, water, soil, animals, plants, coal, minerals, oil, wind, natural gas and sunlight. There are different classifications of natural resources, such as renewable and non-renewable.
Renewable resources are those that are plentiful or replenishable, such as solar energy, plants, air, wind and soil. However, the natural processes involved in the replacement of renewable sources can take either a short or long time depending on the particular resources. For example, trees are important for timber. After they are cut down, it can take many years to see the regrowth of new trees after replanting them. However, sunlight, which provides solar energy, is available every day. Although there can be a plentiful supply of renewable resources on Earth, the depletion of some, such as forests and trees, is possible through their overuse or overconsumption by man.
Resources, such as coal, crude oil and natural gas, are non-renewable because there is only a finite quantity of them available because the formation of these fossil fuels can take millions of years. The depletion of fossil fuels is also possible through their overuse. For this reason, the sustainability and protection of all natural resources are important issues that man has to address.
Another way to categorize natural resources is to classify them according to their origin. Resources that come from living or organic material are biotic resources, and those that come from non-living material are abiotic resources. Biotic resources can include animals, tree, plants, coal and petroleum. Examples of abiotic resources are the air, water and sunlight.