Carbon Cycle
- Jul 1
- 2 min read
The carbon cycle is Earth’s natural, continuous process of recycling carbon atoms.
Carbon is the fundamental building block of all life, and this cycle ensures that it constantly moves between the atmosphere, living organisms, oceans, soil, and rocks.
The Terrestrial Carbon Pathway
Plants absorb atmospheric CO₂ during photosynthesis, converting it into glucose and organic compounds.
Carbon is now stored within the plant’s tissues.
Animals eat plants, moving carbon into their bodies to become part of muscles, fats, and proteins.
Both plants and animals respire, breaking down glucose to release energy and returning CO₂ to the atmosphere.
When organisms die, decomposers (bacteria/fungi) break down the organic matter, respiring and releasing CO₂ back into the atmosphere.
The Aquatic Carbon Pathway
Atmospheric CO₂ dissolves into oceans, lakes, and rivers.
Aquatic plants and algae absorb this dissolved CO₂
Aquatic animals feed on these organisms and release CO₂ through respiration.
Long-term Storage and Fossil Fuels
Fossilization - Over millions of years, dead organisms buried in sediment are converted by heat and pressure into fossil fuels like coal, oil, and natural gas.
Combustion - Humans extract and burn these fuels in vehicles and factories, releasing large amounts of CO₂ into the atmosphere at a rate faster than natural systems can remove it.
Carbon Sinks vs Carbon Sources
Carbon Sinks - Places like forests, oceans, and peat bogs absorb more carbon than they release, helping reduce atmospheric CO₂ levels.
Carbon Sources - Activities like fossil fuel combustion and deforestation release more carbon than they absorb.
The Impact of Imbalance
Today, humans release CO₂ faster than plants and oceans can absorb it. This increases atmospheric CO₂ levels, strengthens the greenhouse effect, and traps heat, leading to global warming, climate change, floods, droughts, melting ice caps, and biodiversity loss.
