We Need Energy Energy is the ability to do work It comes in different forms such as heat light or kinetic movement energy Energy can also be passed from one object to another For example an apple contains sugars which are forms of chemical energy When you eat the apple the chemical energy is transferred to your body You can use it to power your muscles to swing your leg When your leg kicks a ball it transfers kinetic energy from you to the ball We use energy all the time in our daily lives We get energy from food We also release energy by burning fuels such as gasoline and natural gas The energy we use comes from many different sources Some of these sources are more sustainable or efficient to use than others Renewable energy is energy from a source such as the Sun or wind which will never run out However most of the energy we use comes from sources that are nonrenewable so they cannot be replaced We burn huge amounts of fuels such as coal oil natural gas to power our cars and heat our homes These resources are extracted from beneath the ground Once these fuels are burned they World Energy Supply by Source 2012 cannot be used again Eventually there will 4 8 1 1 be no more left 2 4 31 4 10 Hydropower NucleaI Biofuels and waste Coal oil and natural gas make up the biggest slices of this pie which shows the different kinds of energy used around the world Natural gas Coal 21 3 Other
More and More The world's population is growing Currently there are more than 7 billion people on Earth That number will probably reach 9 7 billion in about 25 years Not only will there be more people using energy but they are also likely to use more of it Our busy modern lives use up energy at an amazing rate One of the biggest challenges for the future is finding a way to meet these growing energy needs Electricity powers a huge range of devices from streetlights to smartphones R E W I N D Just 200 years ago no one had electricity in their home or a car to drive from place to place People burned wood or coal to cook their food and heat their homes Candles and simple oil lamps provided light Transportation was by foot boat or horse The world is very different now and we have become dependent on energy for even the simplest tasks In what ways is daily life different now that energy is so readily
What Are Fossil Fuels Fossil fuels are substances such as coal oil also called petroleum or crude oil and natural gas which can all be burned as fuel Fossil fuels are found in deposits deep underground and the name provides a clue about how they got there These kinds of fuels are formed from the remains of living things that died hundreds of millions of years ago When plants and animals died their remains broke down and eventually became buried under layers of mud rock and sand In some places tons of heavy earth covered the remains pressing down on them All this pressure created a lot of heat Over millions of years the heat and pressure changed the plant and animal remains into fossil fuels Coal was formed from dead plants such as trees and ferns Oil and gas were formed from microscopic marine plants and animals whose remains were buried at the bottom of rivers and oceans Once the oil and natural gas were formed they began working their way up through Earth s crust When they ran into layers of rock too dense to seep through they collected in pools called deposits In some places petroleum seeps naturally up to the surface where it can be
Why Fossil Fuels Contain Energy A plant uses sunlight and water to make food for itself This food is a form of chemical energy When an animal such as a mouse eats the plant it takes in this energy The mouse's own body stores energy that can then be passed on to a larger animal such as an owl when it eats the mouse If a plant or animal dies without being eaten the energy remains in their body Over time it can form a fossil fuel The peat in this bog could turn into coal in millions of years if it is buried in hot high pressure conditions FAST FORWARD New deposits of fossil fuels are still being formed However the process is so slow that it will take millions of years before they are usable as fuel One of the first stages in the formation of coal is peat Peat is a type of wet thick soil that is made up of decaying plants It is found on Earth's surface in swampy environments all over the world It builds up slowly at fewer than 0 08 inches 2 mm per year but it cannot start turning into coal until it is buried beneath approximately 330 to 1 300 feet 100 to 400 m of sediment That will take a very long time What do you think might replace coal as an energy source when supplies run out 7
