The Carbon Cycle

Carbon is a chemical element, and is the basis of all known life on Earth. It is important in the ecosystem because it is a key building block of carbohydrates, fats, and proteins, which make up the structure of living organisms. Additionally, carbon is a part of the carbon cycle, which helps regulate the amount of carbon dioxide in the atmosphere, and thereby helps maintain the Earth’s climate.

Table of Contents:

• What is Carbon Cycle?
• Terrestrial Carbon Cycle
• Oceanic Carbon Cycle
• FAQs

What is Carbon Cycle?

The carbon cycle is the process by which carbon is continuously cycled from the atmosphere into living organisms, the oceans, and the Earth’s crust, and then back into the atmosphere.

There are two main types of carbon cycles:

the terrestrial carbon cycle and the oceanic carbon cycle.

Terrestrial Carbon Cycle

The terrestrial carbon cycle refers to the exchange of carbon between the atmosphere, land-based ecosystems, and the Earth’s crust.

It includes the following processes:

Photosynthesis: During this process, plants use energy from sunlight to convert carbon dioxide from the air into organic matter, such as glucose.

Respiration: All living organisms, including plants, release carbon dioxide back into the atmosphere through respiration, where they convert organic matter back into energy.

Decomposition: Dead organic matter, such as fallen leaves and dead plants, is decomposed by microorganisms into simple compounds, including carbon dioxide.

Soil Carbon Storage: Some of the carbon released through respiration and decomposition is stored in the soil, where it can remain for decades to centuries.

Land Use Change: Human activities such as deforestation and agriculture can significantly alter the terrestrial carbon cycle by changing the amount of carbon stored in plants and soils and by releasing carbon dioxide into the atmosphere through burning of forests or the use of synthetic fertilizers.

These processes are in a state of dynamic balance, and changes in one can affect the others and the overall carbon balance. The terrestrial carbon cycle plays a critical role in regulating the amount of carbon dioxide in the atmosphere, and helps to maintain the Earth’s climate.

Here are some examples of the terrestrial carbon cycle:

Photosynthesis by trees and other plants, which converts carbon dioxide from the atmosphere into organic matter.

Decomposition of fallen leaves and dead plants, releasing carbon dioxide back into the atmosphere.

Respiration by plants, animals, and microorganisms, which releases carbon dioxide back into the atmosphere.

Soil carbon storage, where dead organic matter is transformed into soil organic matter and stored for long periods of time.

Deforestation, which removes trees and other vegetation, and reduces the amount of carbon stored in plants and soils.

Agricultural practices, such as tillage, which can release carbon stored in soils into the atmosphere.

Forest fires, which release large amounts of carbon dioxide into the atmosphere.
Reforestation, which increases the amount of carbon stored in vegetation and soil.

These processes are in a state of dynamic balance, and changes in one can affect the others and the overall carbon balance. The terrestrial carbon cycle plays a critical role in regulating the amount of carbon dioxide in the atmosphere, and helps to maintain the Earth’s climate.

Oceanic Carbon Cycle

The oceanic carbon cycle refers to the exchange of carbon between the ocean and the atmosphere. It includes the following processes:

Dissolution of CO2: Carbon dioxide in the atmosphere dissolves into the surface waters of the ocean, forming carbonic acid, which then splits into hydrogen ions and bicarbonate ions.

Transport by ocean currents: The ocean currents transport the dissolved carbon throughout the ocean, spreading it to different depths and latitudes.

Uptake by phytoplankton: Phytoplankton, tiny marine plants, use carbon dioxide during photosynthesis to make organic matter, just like land plants.

Sinking of organic matter: Some of the organic matter produced by phytoplankton sinks to the ocean floor, where it can be stored for centuries to thousands of years.

Release of CO2 through ocean ventilation: The deep ocean releases carbon dioxide back into the atmosphere through a process called ocean ventilation, where deep, cold water rises to the surface, bringing with it carbon dioxide that has been stored for centuries.

Release of CO2 from oceanic sediments: Carbon dioxide can also be released from the ocean floor by geological processes such as volcanic activity and tectonic movement.

These processes are in a state of dynamic balance, and changes in one can affect the others and the overall carbon balance. The oceanic carbon cycle plays a critical role in regulating the amount of carbon dioxide in the atmosphere, and helps to maintain the Earth’s climate.

Here are some examples of the oceanic carbon cycle:

Dissolution of carbon dioxide from the atmosphere into surface waters of the ocean.

Transport of dissolved carbon through ocean currents, such as the Gulf Stream, which carries warm water from the tropics towards the poles.

Uptake of carbon dioxide by phytoplankton during photosynthesis, which converts it into organic matter.

Sinking of phytoplankton-derived organic matter to the ocean floor.

Release of carbon dioxide from deep ocean water to the atmosphere through ocean ventilation, where deep, cold water rises to the surface.

Release of carbon dioxide from oceanic sediments due to volcanic activity and tectonic movement.

Absorption of carbon dioxide by the ocean during periods of low atmospheric carbon dioxide levels, such as during glacial periods.

These processes are in a state of dynamic balance, and changes in one can affect the others and the overall carbon balance. The oceanic carbon cycle plays a critical role in regulating the amount of carbon dioxide in the atmosphere, and helps to maintain the Earth’s climate.

The Carbon Cycle FAQS

Grade 7 Science Worksheets

• Elements and Compounds
• Solar Energy
• Photosynthesis
• Electricity and Magnetism
• Law of conservation of energy
• Periodic table
• Properties of Matter
• Waves
• Energy Resources 
• Weather and Climate
• Immune, Circulatory and Digestive Systems
• Organs in Multi-cellular Organism
• Sedimentary, Igneous, and Metamorphic Rocks
• Structure of the Earth
• Law of Conservation of Mass
• Physical and Chemical Changes
• Scientific Method
• Human Digestive System
• Environmental Science
• Renewable and Non-renewable energy Resources
• Characteristics of Living Organisms
• Life Science
• Earth and Space Science
• Solar Eclipse
• Heat Technology
• Newton’s Laws of Motions
• Physical Science
• Tools, Measurement and SI Units
• Earth Atmosphere
• Interactions of Living things
• The Earth Ecosystem
• Organelles in Plant and Animal cells
• Layers of the Earth
• Cycles in Nature

Grade 7 Math Worksheets

• Fractions
• Linear equations word problems
• Statistics
• Properties of Parallel Line 
• Finding slope from an equation
• Identifying Quadrilaterals
• Percent Change
• Properties of addition and multiplication
• Pythagorean Theorem
• Solving two step inequalities
• Symmetry
• Fractions to Decimals (New)
• Whole Number Exponents with Integer Bases (New)
• Adding and Subtracting Fractions (New)
• Integer Addition and Subtraction (New)
• Dividing Mixed Numbers (New)
• Basics of Coordinate Geometry (New)