Carbon cycle

Definition

The carbon cycle is the process by which carbon moves through different reservoirs in the environment, including the atmosphere, oceans, soil, and living organisms. It involves various processes such as photosynthesis, respiration, decomposition, and combustion, which all contribute to the recycling of carbon within ecosystems. This cycle is crucial for maintaining the balance of carbon in the atmosphere and supports life on Earth.

5 Must Know Facts For Your Next Test

1. The carbon cycle is essential for regulating Earth's climate, as it helps control the levels of carbon dioxide in the atmosphere.
2. Carbon can be stored in various forms, including fossil fuels, organic matter in soils, and dissolved carbonates in oceans.
3. Human activities such as burning fossil fuels and deforestation significantly disrupt the natural carbon cycle by increasing atmospheric carbon dioxide levels.
4. The ocean acts as a major carbon sink, absorbing large amounts of carbon dioxide from the atmosphere and helping to mitigate climate change.
5. Through processes like photosynthesis and respiration, living organisms play a key role in cycling carbon between the atmosphere and terrestrial ecosystems.

Review Questions

• How do natural processes like photosynthesis and respiration contribute to the carbon cycle?
  • Photosynthesis allows plants to capture atmospheric carbon dioxide and convert it into organic compounds like glucose, storing carbon in biomass. Conversely, respiration occurs in plants and animals as they break down glucose for energy, releasing carbon dioxide back into the atmosphere. This continuous exchange between photosynthesis and respiration helps maintain the balance of carbon within ecosystems.
• What are the impacts of human activities on the carbon cycle, particularly regarding climate change?
  • Human activities such as burning fossil fuels for energy and deforestation are increasing the amount of carbon dioxide in the atmosphere beyond natural levels. This additional greenhouse gas contributes to global warming by trapping heat. As a result, climate change is accelerated, affecting weather patterns, sea levels, and ecosystems worldwide.
• Evaluate the importance of the ocean as a carbon sink in relation to global climate regulation.
  • The ocean plays a crucial role as a carbon sink by absorbing approximately 30% of atmospheric carbon dioxide. This process helps mitigate climate change by reducing greenhouse gas concentrations. However, excess absorption can lead to ocean acidification, negatively impacting marine life. Understanding this balance is vital for implementing effective climate strategies and preserving ocean health.

Related terms

photosynthesis:

The process by which green plants, algae, and some bacteria convert carbon dioxide and sunlight into glucose and oxygen.

respiration:

The metabolic process in which organisms convert glucose and oxygen into energy, releasing carbon dioxide as a byproduct.

decomposition: The breakdown of organic matter by decomposers, such as bacteria and fungi, which releases carbon back into the soil and atmosphere.