1. Introduction

Greenhouse gases (GHGs) are atmospheric gases that trap heat from the sun, maintaining Earth’s temperature and enabling life. However, excess GHGs from human activities intensify the natural greenhouse effect, leading to global warming and climate change.

2. Key Greenhouse Gases

Gas Chemical Formula Sources Atmospheric Lifetime Global Warming Potential (GWP)
Carbon Dioxide CO₂ Fossil fuels, respiration ~100 years 1
Methane CH₄ Agriculture, landfills ~12 years 28-36
Nitrous Oxide N₂O Fertilizers, industry ~114 years 265-298
Ozone O₃ Chemical reactions Hours to days Varies
Water Vapor H₂O Evaporation, transpiration Days Varies
F-gases CFCs, HFCs Refrigerants, industry 1-50,000 years 100-12,500

3. The Greenhouse Effect

Greenhouse Effect Diagram

  • Solar radiation reaches Earth.
  • Some energy is absorbed, warming the surface.
  • Earth emits infrared radiation.
  • GHGs absorb and re-emit infrared, trapping heat.

4. Sources and Sinks

Natural Sources

  • Volcanic eruptions (CO₂, SO₂)
  • Wetlands (CH₄)
  • Oceans (CO₂ exchange)

Anthropogenic (Human) Sources

  • Fossil fuel combustion
  • Agriculture (livestock, fertilizers)
  • Industrial processes
  • Deforestation

Sinks

  • Photosynthesis by plants
  • Ocean absorption
  • Soil uptake

5. Surprising Facts

  1. Methane is over 25 times more effective than CO₂ at trapping heat over a 100-year period.
  2. Nitrous oxide emissions from agriculture have increased by 30% since 1980, largely due to fertilizer use.
  3. Some synthetic greenhouse gases, such as SF₆, can persist in the atmosphere for up to 50,000 years.

6. Interdisciplinary Connections

  • Chemistry: Molecular structure determines absorption of infrared radiation.
  • Physics: Radiative transfer and thermodynamics explain heat trapping.
  • Biology: Photosynthesis and respiration regulate CO₂ and O₂ levels.
  • Environmental Science: Impact on climate, ecosystems, and policy.
  • Artificial Intelligence: AI models now predict GHG emissions, optimize carbon capture, and discover new materials for climate mitigation (e.g., AI-designed catalysts for CO₂ conversion).

7. Practical Experiment: Measuring CO₂ Levels

Objective

Measure and compare CO₂ concentrations indoors and outdoors.

Materials

  • CO₂ sensor (NDIR type or smartphone-compatible)
  • Notebook for data recording

Procedure

  1. Calibrate the CO₂ sensor as per manufacturer instructions.
  2. Measure CO₂ levels in a closed room for 10 minutes.
  3. Move outdoors and repeat measurement.
  4. Record temperature and humidity for both locations.
  5. Analyze differences and discuss possible sources (e.g., respiration, ventilation, vehicle emissions).

Discussion Points

  • Why are indoor levels higher?
  • What factors influence outdoor CO₂ concentrations?
  • How do local activities affect measurements?

8. Recent Research

A 2022 study published in Nature (“Artificial intelligence accelerates the discovery of climate solutions”) demonstrated how machine learning algorithms identified novel materials for carbon capture, increasing efficiency by 30% over traditional methods. Read summary

9. Future Trends

  • AI-driven discovery: Advanced algorithms will design new GHG-absorbing materials and optimize climate models.
  • Direct Air Capture: Emerging technologies will remove CO₂ from ambient air at scale.
  • Bioengineering: Genetically modified plants and microbes could enhance natural carbon sinks.
  • Policy Integration: Real-time GHG monitoring will inform adaptive climate policies.
  • Global Collaboration: International treaties will increasingly rely on transparent GHG data and AI analytics.

10. References

  • Nature, 2022. Artificial intelligence accelerates the discovery of climate solutions. Link
  • Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report, 2021.
  • US EPA: Greenhouse Gas Emissions Overview, 2023.

11. Additional Diagrams

Atmospheric Greenhouse Gas Concentrations Over Time

12. Summary Table: Impacts of Major GHGs

Gas Main Impact Mitigation Strategies
CO₂ Warming, ocean acidification Renewable energy, reforestation
CH₄ Intense short-term warming Improved agriculture, waste management
N₂O Ozone depletion, warming Fertilizer management, emission controls
F-gases Long-term warming, ozone depletion Phase-out, alternative chemicals

End of Handout