Fossil fuels are natural resources
Fossil fuels are combustible organic materials such as crude oil (petroleum), mineral coal and natural gas. They are derived from the remains of living matter buried under the surface of the earth millions of years ago. Diesel, petrol and kerosene are extracted from crude oil.
Formation of mineral coal
Mineral coal was formed mainly from the remains of large trees that grew in great swamps more than 300 million years ago. The remains formed layers as they sank under the water of the swamps. The plant material partially decayed and formed layers of peat. Peat is a soft, brown substance that is made. up of 30% carbon. It is the earliest stage of coal formation.
Shallow seas later covered the swamps and slowly deposited layers of sand and mud over the peat. These sediments exerted pressure on the peat over thousands of years. At the same time, slow chemical changes took place which transformed peat to lignite. Lignite is made up of about 40% carbon.
After being subjected to increasing pressure and heat for millions of years, lignite changed into soft coal and finally into hard coal which contains over 90% carbon. Coal is the main source of energy in our country. It is used in thermal power plants to produce electricity.
Formation of crude oil (petroleum) and natural gas
Oil and natural gas are also found in beds of rocks known as sedimentary rocks. Crude oil was formed due to decomposition of marine organisms. Millions of years ago, remain of plants, animals and microorganisms living in the seas, settled at the bottom and were buried under layers of sediment. For millions of years, these layers were subjected to heat and pressure. This transformed the sediments into beds of rock and the plant and animal material underwent slow chemical changes and formed crude oil and natural gas.
Uses of fossil fuels
Fossil fuels are a source of energy for both domestic and commercial uses. They are used to run vehicles, trains, ships and aircraft. It is also used extensively to manufacture plastics and other synthetic materials. Natural gas and coal are sources of feat. Fossil fuels fulfil over 85% of the world’s energy needs.
There are environmental risks associated with extracting, transporting and using fossil fuels. Mining for coal and drilling for oil are especially hazardous because not only can they change the surrounding landscapes, but can also bring massive amounts of salt water to the surface which can damage nearby land and sources of fresh water. Pollution caused by burning fossil fuels Burning natural gas, coal, petrol, diesel and kerosene by industries, automobiles and for household purposes raises the level of carbon dioxide and adds harmful substances such as carbon monoxide, sulphur dioxide. nitrogen oxides and particulate matter in the atmosphere.
This has deteriorated the quality of air. Some of these pollutants(sulphur dioxide and nitrogen oxides) can give rise to acid rain and thereby damage soll and water. To reduce air pollution, it is essential to reduce the use of fossil fuels and use technology that prevents polluting substances from entering the environment.
Consequences of overextraction of coal and petroleum
Fossil fuels are non-renewable natural resources. There is a limited amount of petroleum and coal available in nature. These fuels are not being renewed through rapid natural cycles. Fossil fuels are being depleted at a rate that is thousand times faster than they are formed.
The rate at which humans are using fossil fuels, it is likely that the reserves will soon be exhausted. According to the Statistical Review of World Energy, 2006, it is estimated that worldwide coal reserves will last for about 155 years, oil reserves for 40 years and natural gas will last only for about 65 years.
Conservation of fossil fuels
To reduce dependence and demand on fossil fuels, we should
- Develop alternate sources of energy such as hydel power, solar power, tidal power and biofuels.
- Increase energy efficiency.
- Reduce energy consumption.
Individual actions can make a substantial difference in reducing consumption of fossil fuels.
- Replace incandescent light bulbs with compact scent lamps (CFL) that last longer and use less electricity (energy).
- walk, use a bicycle or public transport whenever possible.
- Moderating heating and cooling by a couple of degrees can reduce energy consumption.
- Turning off electrical appliances and electronic equipment when not in use reduces energy consumption.
- Buying fuel efficient motor vehicles saves fuel.
- Harnessing solar energy for domestic use like cooking, heating water and lighting saves fuels.