Renewable And Non-Renewable Resources

Renewable And Non-Renewable Resources

More commonly, natural resources are classified as

1. Inexhaustible i.e. wind, tidal energy, precipitation, etc. and
2. Exhaustible e.g. ground water, minerals, fuels, food, forests, etc.

Table showing renewable and non-renewable natural resources

The exhaustible resources are further classified into two categories.

Renewable resources.

The resources that can be regenerated artificially or naturally (such as from the biomass of living organisms) are called renewable resources. E.g. crops, forests and other vegetation, wild and domestic animals, microorganisms, water, land (soil), etc.

Non – Renewable resources.

Non – renewable resources are those natural resources which cannot be regenerated or replaced after use or which lack the ability for recycling. Resources with a very long recycling time are also considered non – renewable e.g. fossil fuels (like coal, oil, natural gas) metals, minerals and ores, rocks, etc.

The nature and importance of some of the natural resources is considered here.

Land (soil).

It is a renewable natural resource. Soil is the complex mixture of physical, chemical and biological components. It is an important abiotic factor of ecosystem as it provides water, nutrients and anchorage to plants (producers). The presence and nature of vegetation in any area largely depend on the quality of soil and the various edaphic factors.

Degradation of soil.

Misuse or improper use of soil results in degradation of soil. Such soil becomes unsuitable for plant growth.

Degradation of soil causes loss of vegetation and this, in turn, adversely affects climate and the environment. Hence, conservation and proper management of soil is very important and essential.

Water.

Water is a vitally important renewable natural resource. All organisms need water for survival. Rivers, lakes, ponds, and ground water are the reservoirs of fresh water while oceans are the huge reservoirs of marine water. Rainwater is the natural source for the renewal/replenishment of the water in these reservoirs.

Draught and floods are the two main natural factors responsible for the loss of natural water resources directly or indirectly. In addition, non-judicious use and undue wastage by man also contribute towards the loss of available water. In addition, pollution of water renders it unsuitable for consumption as well as for existence of aquatic flora and fauna.

Reduction in soil water or non-availability of water directly affects vegetation growth and disturbs the environment as a whole.

Water can be conserved by holding the rainwater in catchments areas by constructing dams and then regulating the water supply through canals. Similarly, growing vegetation cover helps to retain soil water.

Forests.

Forests are the vast renewable natural resources. Forests are of immense biological and ecological significance. For example;

(i)    They are the source of forest products like fuel, timber, lumber, food, medicinal plants, fodder, etc.

(ii)       They provide ideal habitat for wild life.

(iii)      They provide vegetation cover to the soil and thus check surface evaporation, increase water-retaining capacity of soil and prevent floods and soil erosion by soil binding.

(iv)     They help in recycling of moisture in the nature and regulate rainfall.

Indiscriminate deforestation reduces rainfall, groundwater level and makes the land barren. This alters the climate of the region. In addition, it disturbs and destroys the wild life.

Hence, conservation of forest is essential. There should be proper balance between harvest of forest and its resources on the one hand and the afforestation on the other.

Wildlife.

In a broader sense, the term wildlife covers any or all organisms which are non-cultivated (e.g. wild plants) and non-domesticated (e.g. wild animals). It also includes microorganisms and all other lesser-known human beings.

One important and essential characteristic feature of the wildlife is that they are very well adapted to their natural environmental conditions. Hence, they grow and survive in their natural habitat without the care of human beings.

Existence of wildlife at all levels of the food chains in any ecosystem is essential for maintaining the ecological balance of that ecosystem. In addition, it must be saved and preserved to maintain the diversity of life. However, wildlife is often threatened with elimination from the region or extinction from the earth.

Thus, to save the wildlife and preserve the diversity of life on earth, it is essential to take definite steps towards conservation of wildlife.

Food.

Terrestrial agriculture is the main source of food for human beings. However, the total land in the world under cultivation is not enough to provide adequate supply of food for the ever-increasing human population. Hence, this creates a condition of food crisis resulting in starvation, malnutrition, etc.

To deal with this crisis, modern agricultural practices are used. This involves industrialization of agriculture and to supplement the agricultural products, the aquaculture (fish farming) and mariculture (aquaculture in oceans) are proving to be of immense value. In fact, oceans have an unlimited potential as source of protein-rich food and raw material, if judiciously used.

Minerals.

These are one of the non-renewable natural resources. Organisms need various minerals for normal metabolism and healthy growth. Besides this, huge quantities of minerals are constantly being used in industries and for technological and cultural purposes.

The two main sources of minerals are:

(i)    The earth’s crust and the parent rocks for terrestrial minerals and

(ii)   The oceans for the marine minerals.

The minerals largely used are of two types :-

(a)  Metallic minerals (e.g. iron, copper, silver, gold, aluminum, lead, zinc, etc.) and

(b)  Non-metallic minerals (e.g. coal, sand, petroleum products, salts, sulphur, phosphorus, etc.)

Fuels and the energy crisis.

Energy is the capacity to do work. It is needed by all organisms for maintenance of life. Similarly, energy is needed constantly and on very large scale for domestic, industrial and technological purposes. In fact, the progress of human civilization and the economic growth of every country largely depend on the resource and supply of energy.

The more commonly used conventional source of energy is the various kinds of fossil fuels. These include petroleum, natural gas (e.g. methane), coal, and synfuels (i.e. naturally occurring organic products which can be converted into synthetic petroleum) such as oil shale, tar sands, etc.

These account for nearly 90% of the world’s production of commercial energy, the remaining 10% coming from the hydroelectric and nuclear power resources. This will be clear from the following figures.

Oil – 39.5%                              Hydroelectric – 6.7%

Coal – 30.3%                           Nuclear power – 3.9%

Natural gas – 19.6%

However, all the fossil fuels are the exhaustible non-renewable natural resources and shall be finished eventually. The realization of this fact is creating the fear of unavoidable energy crisis all over the world. Hence, much before the crisis is reached, it is imperative to

(i)        Adapt urgent measures to conserve and regulate the existing stock of non-renewable energy resources and

(ii)       To find some suitable inexhaustible and/or renewable alternative energy resources.

In this regard, the following non-conventional renewable sources of energy hold considerable potential and promise, if investigated and exploited properly. These are

Solar energy

(i)        Wind energy

(ii)       Tidal (ocean) energy

(iii)      Geothermal energy, etc.

In addition, there are number of biomass-based renewable energy systems. These include energy sources such as

(i)        Fire wood

(ii)       Petro plants (i.e. potential plant species, which can be the source of liquid hydrocarbons to be used as a substitute for liquid fuels.

(iii)      Biogas

(iv)     Electric energy, etc.