Carbon dioxide (CO2)

Definition

Carbon dioxide (CO2) is a colorless, odorless gas that is a natural part of Earth's atmosphere, primarily produced by the respiration of living organisms and the combustion of fossil fuels. This greenhouse gas plays a crucial role in climate feedback mechanisms, as it traps heat in the atmosphere and contributes to global warming and climate change.

5 Must Know Facts For Your Next Test

1. CO2 levels have significantly increased since the Industrial Revolution, primarily due to human activities such as burning fossil fuels and deforestation.
2. The concentration of CO2 in the atmosphere is measured in parts per million (ppm), with current levels surpassing 400 ppm for the first time in millions of years.
3. CO2 is not only a product of combustion but also plays a role in photosynthesis, where plants absorb it and release oxygen, highlighting its dual role in Earth's ecosystems.
4. The oceans absorb a significant amount of CO2, which leads to ocean acidification, affecting marine life and ecosystems.
5. Climate feedbacks involving CO2 include its interaction with water vapor and ice albedo changes, both of which amplify warming effects.

Review Questions

• How does carbon dioxide contribute to the greenhouse effect and what implications does this have for climate change?
  • Carbon dioxide contributes to the greenhouse effect by absorbing infrared radiation emitted from Earth’s surface and re-radiating it back towards the surface. This process leads to an increase in global temperatures, exacerbating climate change. The rising levels of CO2 from human activities intensify this effect, causing more heat to be trapped in the atmosphere and leading to changes in weather patterns, melting polar ice, and rising sea levels.
• Discuss the impact of elevated CO2 levels on both terrestrial and marine ecosystems.
  • Elevated levels of CO2 affect terrestrial ecosystems primarily through increased temperatures and altered precipitation patterns, which can lead to shifts in plant species distributions and biodiversity loss. In marine ecosystems, higher CO2 concentrations result in ocean acidification, negatively impacting coral reefs and shellfish as they struggle to form their calcium carbonate structures. Both ecosystems face stressors that can disrupt food webs and ecosystem services essential for human survival.
• Evaluate the relationship between human activities and atmospheric carbon dioxide levels, considering long-term environmental consequences.
  • Human activities such as industrialization, deforestation, and agriculture have dramatically increased atmospheric carbon dioxide levels since the Industrial Revolution. This increase has long-term environmental consequences, including accelerated climate change, disruption of weather patterns, loss of biodiversity, and alterations to natural habitats. These changes not only threaten global ecosystems but also pose risks to food security and human health as communities adapt to an increasingly volatile climate.

Related terms

Greenhouse Effect: The process by which certain gases, including CO2, trap heat in the Earth's atmosphere, leading to an increase in global temperatures.

Carbon Cycle: The continuous movement of carbon atoms between the atmosphere, land, oceans, and living organisms, which regulates the levels of CO2 in the atmosphere.

Fossil Fuels: Natural substances like coal, oil, and natural gas that are formed from decomposed organic matter, their combustion releases CO2 into the atmosphere.