What is the Greenhouse Effect?
- The Greenhouse Effect is the process by which certain gases in the Earth’s atmosphere trap heat, preventing it from escaping into space.
- This keeps Earth’s average temperature (~15°C) suitable for life.
How Does the Greenhouse Effect Work?
- Sun’s Radiation (Insolation) ☀️ – The Sun emits shortwave radiation (visible light, UV, infrared).
- Earth Absorbs Heat 🌍 – The land and oceans absorb 51% of solar radiation.
- Earth Emits Heat 🔥 – The Earth re-emits heat as longwave infrared radiation.
- Greenhouse Gases Trap Heat 🌡️ – Some heat escapes, but greenhouse gases trap a portion, keeping the planet warm.
Major Greenhouse Gases (GHGs) & Their Sources
| Greenhouse Gas | Symbol | Main Source | Effect |
|---|---|---|---|
| Carbon Dioxide | CO₂ | Burning fossil fuels, deforestation | Main contributor to global warming |
| Methane | CH₄ | Livestock, wetlands, rice paddies | 25x more powerful than CO₂ |
| Nitrous Oxide | N₂O | Fertilizers, industries | 300x more powerful than CO₂ |
| Water Vapor | H₂O | Evaporation, clouds | Most abundant natural GHG |
| Chlorofluorocarbons (CFCs) | CFCs | Refrigerants, ACs, aerosols | Destroys ozone layer |
Types of Greenhouse Effects
1. Natural Greenhouse Effect 🌍
✅ Essential for maintaining Earth’s temperature (~15°C).
✅ Without it, the Earth would be -18°C (too cold for life).
2. Enhanced Greenhouse Effect (Global Warming) 🌡️
❌ Human activities (burning fossil fuels, deforestation) increase GHGs, trapping excess heat.
❌ Causes climate change, melting ice caps, and extreme weather.
Effects of the Greenhouse Effect & Global Warming
❌ Rising Temperatures – More GHGs = higher global temperatures.
❌ Melting Glaciers & Sea Level Rise – Threatens coastal cities.
❌ Extreme Weather Events – More heatwaves, storms, droughts.
❌ Loss of Biodiversity – Many species cannot adapt to rapid climate changes.
❌ Ocean Acidification – Excess CO₂ makes oceans more acidic, harming marine life.
Measures to Reduce Greenhouse Effect
✔ Afforestation & Reforestation – Trees absorb CO₂.
✔ Reduce Fossil Fuel Use – Switch to solar, wind, hydro energy.
✔ Energy Efficiency – Use LED bulbs, efficient appliances.
✔ Reduce Industrial Emissions – Stricter laws for factories.
✔ Use Public Transport & Electric Vehicles – Less fuel consumption.
✔ Ban CFCs – Protects ozone layer from depletion.
International Efforts to Control Greenhouse Effect
| Agreement | Year | Objective |
|---|---|---|
| Kyoto Protocol | 1997 | Reduce GHG emissions by developed nations |
| Paris Agreement | 2015 | Limit global warming to below 2°C |
| Montreal Protocol | 1987 | Phase out ozone-depleting substances (CFCs) |
MCQs on Greenhouse Effect
1. Which gas is the main contributor to the greenhouse effect?
a) Oxygen
b) Carbon Dioxide
c) Helium
d) Hydrogen
Answer: b) Carbon Dioxide
2. Which gas is the most powerful greenhouse gas?
a) CO₂
b) CH₄
c) N₂O
d) CFCs
Answer: c) N₂O (300x stronger than CO₂)
3. Which human activity increases CO₂ levels the most?
a) Afforestation
b) Burning fossil fuels
c) Using solar energy
d) Hydroelectric power
Answer: b) Burning fossil fuels
4. What is the main objective of the Paris Agreement?
a) Reduce plastic waste
b) Protect endangered species
c) Limit global warming below 2°C
d) Ban nuclear weapons
Answer: c) Limit global warming below 2°C
5. Which greenhouse gas is released by livestock farming?
a) CO₂
b) CH₄ (Methane)
c) N₂O
d) CFCs
Answer: b) CH₄ (Methane)
Short Answer Questions
1. What is the greenhouse effect?
The greenhouse effect is the process where certain gases trap heat in the Earth’s atmosphere, keeping the planet warm.
2. Name three greenhouse gases and their sources.
- Carbon Dioxide (CO₂) – Fossil fuels, deforestation.
- Methane (CH₄) – Livestock, wetlands.
- Nitrous Oxide (N₂O) – Fertilizers, industries.
3. What are two impacts of global warming?
- Melting glaciers & sea level rise.
- More extreme weather (heatwaves, storms, floods).
4. How can we reduce the greenhouse effect?
- Use renewable energy (solar, wind).
- Plant more trees (absorb CO₂).
- Reduce industrial pollution.
- Use public transport & electric vehicles.
5. What was the purpose of the Kyoto Protocol?
To reduce greenhouse gas emissions in developed nations.
Conclusion
The greenhouse effect is essential for life, but human activities are making it too strong, leading to global warming and climate change. Urgent action is needed to reduce emissions and adopt sustainable practices.
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