AB

In-Depth Notes on Earth's Climate and Greenhouse Gases

Earth's Climate and Greenhouse Gases

  • Introduction to Greenhouse Gases (GHGs)
    • GHGs play a significant role in regulating Earth's climate by trapping heat in the atmosphere.

Greenhouse Gases in the Atmosphere

  • Composition of the Atmosphere:

    • Nitrogen: 78%
    • Oxygen: 20.9%
    • Argon: 0.90%
    • Carbon Dioxide: 0.03%
    • Other gases: 0.17%

  • Major Greenhouse Gases:

    • Carbon Dioxide (CO₂)
    • Methane (CH₄)
    • Nitrous Oxide (N₂O)
    • Water Vapour (H₂O)

Greenhouse Effect

  • The greenhouse effect occurs when GHGs trap heat in the atmosphere, acting like a blanket that keeps Earth warm.
  • Without GHGs:
    • Earth’s average temperature would be around -18°C.
  • Consequences of Increased Fossil Fuel Use and Deforestation:
    1. Increased GHG emissions leading to a stronger greenhouse effect.
    2. Higher average global temperatures, disrupted climates, and changing weather patterns.

Human Impact on the Greenhouse Effect

  • The human-enhanced greenhouse effect is caused by the excessive production of GHGs due to:
    • Deforestation
    • Fossil Fuel Use
  • Essential distinction: In the natural greenhouse effect, more heat escapes into space. In the human-enhanced version, less heat escapes, leading to global warming.

Misconceptions about Climate Change

  • Climate Change vs. Ozone Depletion:
    • They are separate issues.
    • Climate Change: Gradual increase in Earth's temperature due to GHGs.
    • Ozone Depletion: Thinning of the ozone layer caused by fluorinated gases, increasing UV radiation.

Effects of Climate Change

  • Potential impacts of increased GHGs in the atmosphere include:
    1. Rising global temperatures.
    2. Rising sea levels.
    3. Melting ice caps.
    4. Increased frequency of forest fires.
    5. More intense hurricanes.

Positive Feedback Loop

  • Definition: A process that exacerbates climate change instead of reversing it.
    • Example: Rising temperatures lead to melting ice, reducing the albedo effect and causing more heat absorption, prompting further temperature increases.

Research Task on Climate Change Effects

  • Student task: Research a recent article detailing an effect of climate change:
    1. Identify and summarize key points from the article.
    2. Make sure it includes both qualitative and quantitative information.

Evaluating Sources for Climate Change Information

  • Use the ABCD method to assess article quality:
    • A (Author): Expertise and qualifications of the author.
    • B (Bias): Objectivity and neutrality of the content.
    • C (Content): Relevance and complexity of the information.
    • D (Date): Timeliness and current relevance of the information.

Intergovernmental Panel on Climate Change (IPCC)

  • Established by the UN in 1988 to evaluate climate change science.
  • Aims to present scientifically accurate reports on climate issues, addressing:
    • Impacts of climate change.
    • Adaptation strategies.
    • Mitigation efforts.
  • Reports are politically neutral and intended for policy-making guidance.

Summary of Major IPCC Reports:

  • WGI: The Physical Science Basis of climate change.
  • WGII: Impacts, Adaptation and Vulnerability.
  • WGIII: Mitigation of Climate Change.
  • Special Reports on various climate-related topics, including oceans, land use, and global warming pathways.

Conclusion

  • Understanding GHGs and their effects is essential for addressing climate change. Awareness, evaluation of sources, and research contribute significantly to comprehensive knowledge in this field.