Carbon dioxide

Definition

Carbon dioxide (CO₂) is a colorless, odorless gas that occurs naturally in Earth's atmosphere and is produced by the respiration of animals and plants, the combustion of fossil fuels, and other processes. It is a significant greenhouse gas, trapping heat in the atmosphere and contributing to global warming and climate change, making it a critical factor in environmental risk assessments.

5 Must Know Facts For Your Next Test

1. Carbon dioxide levels in the atmosphere have increased significantly since the Industrial Revolution, primarily due to human activities such as burning fossil fuels for energy.
2. CO₂ is absorbed by oceans, rivers, and lakes, where it can contribute to ocean acidification, affecting marine ecosystems and biodiversity.
3. The concentration of carbon dioxide is measured in parts per million (ppm), with current levels exceeding 400 ppm, the highest they have been in over 800,000 years.
4. Trees and plants absorb carbon dioxide during photosynthesis, playing a crucial role in regulating atmospheric CO₂ levels.
5. Mitigating carbon dioxide emissions is vital for achieving international climate goals set out in agreements like the Paris Agreement.

Review Questions

• How does carbon dioxide function as a greenhouse gas and what are its implications for climate change?
  • Carbon dioxide acts as a greenhouse gas by trapping heat emitted from the Earth's surface. This process creates a warming effect known as the greenhouse effect, which is crucial for maintaining a habitable climate. However, increased concentrations of CO₂ due to human activities enhance this effect, leading to global warming and significant environmental risks such as extreme weather patterns and rising sea levels.
• Discuss the impact of increased carbon dioxide levels on ocean ecosystems.
  • Increased levels of carbon dioxide lead to higher rates of absorption by oceans, resulting in ocean acidification. This phenomenon disrupts the chemical balance of seawater, negatively affecting marine life such as coral reefs and shellfish that rely on calcium carbonate for their structures. The decline in these species can have cascading effects on marine food webs and overall biodiversity.
• Evaluate the effectiveness of current strategies aimed at reducing carbon dioxide emissions in addressing climate change.
  • Current strategies for reducing carbon dioxide emissions include transitioning to renewable energy sources, improving energy efficiency, and promoting reforestation. These efforts are essential for mitigating climate change impacts; however, their effectiveness is often hindered by political, economic, and social barriers. An integrated approach that includes policy changes, technological innovations, and public engagement is necessary to achieve substantial reductions in CO₂ emissions and meet international climate targets.

Related terms

Greenhouse Gas: Gases in the Earth's atmosphere that trap heat and contribute to the greenhouse effect, including carbon dioxide, methane, and nitrous oxide.

Carbon Footprint: The total amount of greenhouse gases emitted directly or indirectly by an individual, organization, event, or product, usually expressed in equivalent tons of CO₂.

Climate Change: Long-term alterations in temperature, precipitation, wind patterns, and other elements of the Earth's climate system, primarily driven by human activities like burning fossil fuels.