In carbon cycle, sources release carbon dioxide into the atmosphere while sinks absorb or take in carbon dioxide from the atmosphere and store it. In this lesson, we will look at one of the largest sources of carbon dioxide -- fossil fuels. We will learn how fossil fuels were formed and how they're used to provide heat, energy, and transportation. And finally, we will learn about the impact of burning fossil fuels on the greenhouse effect.

Fossil fuels are natural materials, such as oil, coal, or gas, that are burned to create energy. You may know the word fossil; fossils are what remains of plants or animals that lived long, long ago. One example is the impression of a leaf or a small animal from millions of years ago that we see in a rock today. Fossil fuels are also what remains from living things from millions and millions of years ago.

How are fossil fuels made?

Fossil fuels are formed from the decomposition of living organisms. The most common examples are oil, natural gas, and coal. Oil and natural gas were created when plants and animals that died sank to the bottom of the oceans and rivers and were buried by sediment. Those sediments would have been things like stones in sand that washed into the water and then sink to the bottom. After time, there were many layers of sediment, and a great deal of pressure and heat were created. In this intense environment, the remains were decomposed.

Compounds are composed of two or more separate elements. So to make a compound simpler, you take them apart, so that each compound has fewer elements. Millions of years later, these compounds became oil or natural gas.

Coal is created in a similar way. For coal, it was trees or other plants that were buried in wet swamplands. When the plants died, they fell into the bottom of the swamps. As time went by, more plants died, and they formed a thick layer at the bottom of the water. These layers were then buried by dirt and water. The heat and pressure under, at the bottom of the piles, cause chemical reactions. In the end, after the oxygen was pushed out and mostly carbon remained, the materials that were left became coal. Oil, natural gases, and coal have all played an important part in helping the world develop since the Industrial Revolution, when modern machines were invented to make our lives better.

How are fossil fuels used?

In modern society, many places in the world get their electricity so easily by simply plugging in a cord into a wall, but that electricity must be created somewhere. The largest share of greenhouse gas emissions come from burning fossil fuels, mostly coal and natural gases, to make electricity.

In modern society, it is also very convenient and easy to get from one place to another. You can visit another city or another country in one day, but most forms of transportation also depend on fossil fuels. Planes, trains, cars, trucks, ships -- they burn oil products, such as gasoline, petrol, or diesel, to make them run. Factories that make everything that we fill our stores with, such as clothes, toys, electronics, and cars, all use the burning of fossil fuels to make their machines work and to heat their buildings.

What is the impact of fossil fuels?

As we can see, most of us depend on burning fossil fuels for making almost everything we use and taking us almost everywhere we go. But burning so many fossil fuels does have an impact on the environment. It pushes all the carbon dioxide that was stored in the Earth up into the atmosphere in a way that would not happen naturally in the carbon cycle. And as we learned before, carbon dioxide is a greenhouse gas. So, when there is more of it floating around the atmosphere, that means more heat is trapped from escaping our greenhouse -- the Earth's atmosphere.

How it affects the ecosystem?

Greenhouse gases have far-ranging environmental and health effects. They cause climate change by trapping heat, and they also contribute to respiratory disease from smog and air pollution. Extreme weather, food supply disruptions, and increased wildfires are other effects of climate change caused by greenhouse gases. The typical weather patterns we've grown to expect will change; some species will disappear; others will migrate or grow. (Nunez, 2019)

"Cause" means the reason that something happens. So, in the sentence, "the rainstorm was the cause of the flooding". The rainstorm is the reason why the flooding happened.

"Effect", on the other hand, means the consequence of an action. So, if we take our earlier sentence, and look at it in another way, we can say the flooding was the effect of the rainstorm, meaning that the flooding was the result of the action.

With the topic of climate change, it is very important to understand the relationship between different events to know which actions or events cause the others. The things we can see are often effects, but it is too late to change anything at that point. Only by changing the cause of an action can we prevent an effect from happening.

How can we show the relationship between cause and effect?

Okay, so now that we know the difference between a cause and an effect, let's look at some of the ways that we can show this relationship. The words that we use to show these relationships are called "connectors". A connector is something that joins two or more things together. In this case, we're joining clauses together.

In earlier lessons, we looked at the causes of global warming. We saw that more carbon dioxide or CO2 in the atmosphere causes clouds that trap the sun's heat making the Earth warmer. So, there is a relationship between more CO2 in the atmosphere, the cause, and more of the sun's heat being trapped, the effect.

Using connectors and putting the cause first

Let's talk about that relationship using connectors and putting the cause first.

We can say this in a few different ways:

1.There is more CO2 in the atmosphere so more of the sun's heat is trapped.

2.There is more CO2 in the atmosphere; therefore, more of the sun's heat is trapped.

3.There is more CO2 in the atmosphere, consequently, more of the sun's heat is trapped.

So, we can make a sentence by talking about the cause followed by so, therefore, or consequently, and then the effect.

Using connectors and putting the effect first

We can make sentences by putting the effect first as well. Let's look at a few examples of this. We'll use the same situation with CO2 in the atmosphere, and the heat trapped, and use different connectors. We can say:

1.More of the sun's heat is trapped because of more CO2 in the atmosphere.

2.More of the sun's heat is trapped as a result of more CO2 in the atmosphere.

3.More of the sun's heat is trapped due to more CO2 in the atmosphere.

So, we can construct the sentence by talking about the effect followed by because of, as a result, or due to, and then the cause.

The relationship between a cause and an effect. We saw that you can use connectors to accurately show this relationship. We can talk about the cause first followed by the connectors so, therefore, or consequently. Or we can talk about the effect followed by the connectors because of, as a result of, or due to.

Image Credit:

This work is a derivative of an untitled image by Chris Haws via Unsplash under Unsplash license, an untitled image by PublicDomainPictures, an untitled image by Onze Creativijd ,

and an untitled image by jp26jp via Pixabay under Pixabay license

This derivative is licensed under CC BY 4.0 by FHI 360 for use in the OPEN program, sponsored by the U.S. Department of State with funding provided by the U.S. government and administered by FHI 360.

Additional Reference:

Nunez, C. (2019) Carbon dioxide levels are at a record high. Here's what you need to know. National Geographic. Retrieved https://www.nationalgeographic.com/environment/article/greenhouse-gases#:~:text=Greenhouse%20gases%20have%20far%2Dranging,change%20caused%20by%20greenhouse%20gases.