Effects of Greenhouse Gases - IGCSE Chemistry Revision Notes

Introduction

• The Sun emits energy as radiation which enters Earth's atmosphere.
• Some thermal energy is absorbed by Earth's surface while some is reflected.
• This energy is re-emitted back into the atmosphere.
• Some energy escapes into space; some energy is absorbed by greenhouse gases.
• Greenhouse gases include: Carbon dioxide (CO2) and Methane (CH4).

Greenhouse Effect

• Process:
  • Thermal energy absorbed by greenhouse gases is re-emitted in all directions.
  • This traps heat within Earth's atmosphere, maintaining Earth's temperature.
• Significance:
  • It's a natural process necessary for life on Earth.

Enhanced Greenhouse Effect

• Cause:
  • Increased concentration of greenhouse gases due to human activities.
• Result:
  • More heat trapped, leading to a rise in Earth's average temperature (Global Warming).

Consequences of Global Warming

• Climate Change: Increase in Earth's temperature causes changes in climate patterns.
• Rising Water Levels: Melting glaciers lead to floods in low-lying areas.
• Extinction of Species: Loss of natural habitats threatens species survival.
• Migration of Species: Species move to more habitable areas.
• Spread of Diseases: Warmer climates may increase disease spread.
• Loss of Habitat: Animals living in glaciers or low-lying countries lose habitats.

Conclusion

• The greenhouse effect is crucial for life, but human activities are enhancing this effect, leading to global warming and significant environmental changes.
• Addressing greenhouse gas emissions is essential to mitigate these impacts.