The Carbon Cycle
Hey there! I’m sure you’ve heard about the water cycle before. But did you know there’s the carbon cycle as well? Before we move on to the Carbon cycle, let me talk about carbon as an element first.
Some carbon can be found as a free element in the Earth’s crust. It exists in two forms: graphite and diamonds. So graphite and carbon are allotropes (different forms of the same element).
However, there are thousands of carbon compounds in nature. They can be found in living things, in the soil, in the oceans and in the atmosphere.
Carbon moves between compounds in the atmosphere, living things, the soil and the ocean in a continuous journey. This journey is called the Carbon Cycle. So basically, the Carbon Cycle is the circulation and transformation of carbon (in the form of carbon dioxide) back and forth between living things and the environment!
Here’s an illustration of it for better understanding! 😊
Soooo now let’s talk about how…
1. CO2 is added to the atmosphere:
- Animals and plants (in the absence of sunlight) produce CO2 as a product after the uptake of oxygen and glucose.
- C6H12O6 + 6O2 → 6CO2 + 6H2O
- glucose + oxygen → carbon dioxide + water + energy
By combustion of fuels
- CO2 is released upon the burning of methane and natural gas
- CH4(g) + 2O2(g) CO2(g) + 2H2O(l)methane + oxygen → carbon dioxide + energy
2. CO2 is removed from the atmosphere
- By photosynthesis
Plants use CO2 to photosynthesise and synthesis their own food.
*this includes plants in the ocean such as phytoplankton which get eaten by fish and other animals. So carbon is passed along food chains in the ocean.
6CO2 + 6H2O C6H12O6 + 6O2
Carbon dioxide + water → glucose + oxygen
- By dissolving
CO2 in the air dissolves in the ocean and provides carbonates ions, needed to build the shells (made of calcium carbonate) of shellfish as well as the skeletons of fish.
Okay, some of you might still be confused…or might even think, how am i gonna remember all this?!
Well, don’t worry yall. WE INTRODUCE TO YOU… THE CARBON CYCLE SONG!!
JAM TO THIS EVERY DAY AND YOU’LL GET A* FOR ANY CARBON CYCLE EXAM! 😉😎
FACT FILE #1: CARBON DIOXIDE
Other than knowing carbon dioxide is a gas we breathe out, do you know anything else about it?
Well, let me enlighten you! 😁
First of, what is carbon dioxide? Simply put, it’s a colorless, odorless greenhouse gas which consists of one carbon atom and two oxygen atoms chemically bonded to each other! Therefore, its chemical formula is CO2.
Now, to distinguish carbon dioxide from other gases, you must first know its properties. Carbon Dioxide has a number of properties. These properties are:
- being colorless and odorless
- it’s a linear covalent molecule
- it is much heavier in air
- it doesn’t support combustion (so things won’t burn in it, things will only burn when oxygen is present!)it is slightly soluble in water, forming carbonic acid H2CO3 (one of the acids in acid rain which will corrode buildings) NOTE: CO2 is also soluble in ethanol and acetone
- Carbon dioxide is an acidic oxide and reacts with water to give carbonic acid.
- CO2 + H2O ⇌ H2CO3
- Carbon dioxide reacts with alkalis to give carbonates and bicarbonates.
- (sodium bicarbonate)
- (sodium carbonate)
How is Carbon Dioxide formed?
There are a number ways carbon dioxide can be produced. It occurs naturally in the air as a product of:
1.Complete combustion of carbon containing substances
- Eg. methane burning in air
methane + oxygen —> carbon dioxide + water
CH4(g) + 2O2(g) —> CO2(g) + 2H2O (l)
2.Respiration in cells
glucose + oxygen —> carbon dioxide + water
C6H12O6(aq) + 6O2 (g) —> 6CO2 (g) + 6H2O (l)
3.Reactions between dilute acid and carbonates
calcium carbonate + hydrochloric acid —> carbon dioxide + water
CaCO3(s) + 2HCl (aq) —> CaCl2 (aq) + CO2 (g) + H2O (l)
4.Thermal decomposition of a carbonate
calcium carbonate —> calcium oxide + carbon dioxide
CaCO3(s) —> CaO (s) + CO2 (g)
Simple, right? Now, let’s move on to fact file #2: Methane! 😀
FACT FILE #2: METHANE
Methane and Carbon Dioxide are very similar because they are both colorless, odorless, greenhouse gases!
HOLD UP. It’s my bad for not mentioning this earlier…oops😶
What does it mean when both Methane and Carbon Dioxide are greenhouse gases? Well, it means that they are both
First things first though…
What is Methane?
Just like Carbon Dioxide, it is also a colorless, odorless gas. The only difference is that Methane is also a flammable gas. This compound consists of one carbon atom and four hydrogen atoms -CH4
And what are it’s properties?
- it is an organic compound
- it is colorless and odorless
- it is easily ignited (very flammable gas!)
its vapors are lighter than air
But how is Methane formed?
Okay, I need full concentration for this. Ready? Good.
Methane can be found in 3 different places:
- Firstly, Methane is found in gas deposits in the ocean floor and on land, as natural gas.
- Secondly, Methane is produced when bacteria breaks down plant material in the absence of oxygen (e.g. in paddy fields, swamps and landfill sites)
- Lastly, some animals like cattle, sheep, goats and camels give out methane as waste gas from digestion.
If you noticed, all of the above are natural occurring processes. So…what about the man-made processes? Well, we’re gonna be discussing that now!
MAJOR SOURCES OF…
- CO2 is naturally present in the atmosphere as part of the Earth’s carbon cycle (the natural circulation of carbon among the atmosphere, oceans, soil, plants, and animals).
- Respiration of living things
Man-made (responsible for the increase of CO2 since the industrial revolution)
- the combustion of fossil fuels (coal, natural gas, and oil) for energy and transportation, although certain industrial processes and land-use changes also emit CO2.
- Deforestation, this influences the ability of natural sinks, like forests, to remove CO2from the atmosphere
- Decomposition of vegetation (e.g wetlands, rice paddies)
- Waste gases from digestion of animals
- Coal mines
- Waste from homes and businesses (landfill sites)
- Agricultural activities (due to the increasing number of bred livestock, more cows are releasing methane into the atmosphere)
- Industry (use of natural gas and petroleum)
Okay, now lets talk about the negative impacts these two gases have on the earth.
Despite their usefulness in our everyday life activities, we must not forget that carbon dioxide and methane are both greenhouse gases that contribute to global warming…*
Okay, I’m gonna start bombarding you with some alarming facts about this matter, so get ready…
- 72% OF THE TOTALLY EMITTED GREENHOUSE GASES IS CARBON DIOXIDE (C02) AND 18% IS METHANE!
- EMISSIONS OF CO2 HAVE BEEN DRAMATICALLY INCREASING WITHIN THE LAST 50 YEARS AND ARE STILL INCREASING BY 3% EACH YEAR! AND A LARGE PART OF IT IS BECAUSE OF THE NAUGHTY HUMANS!!
THINK ABOUT ALL THE POLAR BEARS IN THE ARCTIC CIRCLE LOSING THEIR HOMES BECAUSE OF GLOBAL WARMING! 😦 😭
*THEYRE SO CUTE, JUST LOOK AT THEM*
But how do Methane and Carbon Dioxide make the earth warmer? I mean, they’re just gases right?
NOT RIGHT. Let me clear things up.
Okay, so the temperature of the Earth depends on a balance between incoming energy from the Sun and the energy that bounces back into space. Greenhouse gases including carbon dioxide and methane forms a layer around Earth which absorbs heat that would otherwise be lost to space. Some of this energy is re-emitted back to Earth, causing additional heating of the planet.
By the way, this is called the greenhouse effect!
You might think, what’s so bad about more heat energy? I can get a better sun tan right😎
BUT DID U KNOW? Excess carbon dioxide lets stronger sun rays penetrate the atmosphere, causing temperatures to rise.
So the more CO2 and CH4 there is, the thicker the layer will be, causing our planet to be hotter. And the hotter it is, the more the climate changes. Das nasty because bad things like flooding, tsunamis and rising sea levels will happen causing animals and people to die and das not good at all.
OK! So now we know the major sources of carbon dioxide and methane and how they can heat up the earth. If we all try to avoid carrying out activities that would produce these gasses unnecessarily , such as smoking (which you all shouldn’t be doing at this age…AHEM) and burning rubbish, we can reduce the amount of greenhouse gasses emitted into the air! AND THE POLAR BEARS IN THE ARCTIC CIRCLE DON’T HAVE TO WORRY ABOUT LOSING THEIR HOUSES!! 😀
PLEASE, LET’S JUST SAVE THESE CUTE AND LOVING CREATURES THAT DIDNT DO US ANY HARM OK
*inserts more cute pictures to make yall feel guilty*
Heh, sorry our team just really loves animals 😋
And we’re done!
- Complete Chemistry for Cambridge IGCSE Textbook 3rd edition
- https://timeforchange.org/CO2-cause- of-global- warming
- https://www.reference.com/science/carbon-dioxide- cause-global- warming-833feae80d37fe85