Carbon dioxide

Definition

Carbon dioxide (CO2) is a colorless, odorless gas that is naturally present in Earth's atmosphere and plays a crucial role in various biogeochemical processes. It is produced by the respiration of animals and plants, combustion of fossil fuels, and decomposition of organic matter, making it a key player in ocean chemistry, atmospheric conditions, climate regulation, and the carbon cycle.

5 Must Know Facts For Your Next Test

1. Carbon dioxide is absorbed by oceans, where it reacts with seawater to form carbonic acid, leading to ocean acidification that negatively impacts marine organisms like corals.
2. In the atmosphere, CO2 levels have risen significantly since the Industrial Revolution due to human activities such as burning fossil fuels and deforestation.
3. The greenhouse effect occurs when CO2 and other greenhouse gases trap heat in the atmosphere, contributing to global warming and climate change.
4. The carbon cycle involves processes like photosynthesis and respiration, where CO2 is taken up by plants and released by animals, maintaining a balance in ecosystems.
5. Evidence of global climate change includes rising temperatures, melting ice caps, and shifts in weather patterns attributed largely to increased CO2 concentrations.

Review Questions

• How does carbon dioxide contribute to ocean acidification and what are its implications for marine ecosystems?
  • Carbon dioxide contributes to ocean acidification when it dissolves in seawater, forming carbonic acid. This process decreases the pH level of the ocean, which can harm marine organisms such as corals and shellfish that rely on calcium carbonate for their structures. The decline in these organisms affects biodiversity and disrupts marine food webs, leading to significant ecological consequences.
• Discuss the role of carbon dioxide in the greenhouse effect and its impact on climate regulation.
  • Carbon dioxide is a significant greenhouse gas that absorbs infrared radiation emitted from Earth’s surface. By trapping heat in the atmosphere, CO2 enhances the greenhouse effect, leading to an increase in global temperatures. This temperature rise contributes to climate change, resulting in altered weather patterns, sea level rise, and extreme weather events that impact both natural ecosystems and human societies.
• Evaluate the connections between carbon dioxide emissions from human activities and the evidence of global climate change observed today.
  • Human activities such as burning fossil fuels, deforestation, and industrial processes have drastically increased carbon dioxide emissions since the late 19th century. This rise in CO2 levels correlates with observable evidence of global climate change, including increased average temperatures, more frequent extreme weather events, and accelerated glacial melting. The overwhelming scientific consensus links these changes directly to anthropogenic CO2 emissions, emphasizing the urgent need for mitigation strategies to reduce our carbon footprint.

Related terms

Photosynthesis: The process by which green plants and some other organisms use sunlight to synthesize foods with the help of carbon dioxide and water.

Ocean Acidification: The decrease in pH levels of the ocean caused by the absorption of excess atmospheric CO2, leading to harmful effects on marine life.

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