Greenhouse gases (GHGs) are a key driver of global warming. Here’s how they contribute:
🔥 1. The Greenhouse Effect Basics
- The Sun’s energy reaches Earth mostly as visible light.
- Earth absorbs some of this energy and warms up.
- The planet then radiates heat (infrared radiation) back toward space.
- Greenhouse gases in the atmosphere trap some of this heat, preventing it from escaping directly into space.
- This natural process keeps Earth warm enough to support life.
🌡️ 2. How Greenhouse Gases Work
Common GHGs include:
- Carbon dioxide (CO₂)
- Methane (CH₄)
- Nitrous oxide (N₂O)
- Water vapor (H₂O)
- Fluorinated gases (synthetic)
- These gases are transparent to incoming sunlight but absorb and re-emit infrared radiation.
- This traps heat in the atmosphere, creating a “blanket” effect.
📈 3. Human Activities Increase GHGs
- Burning fossil fuels (coal, oil, gas) releases CO₂.
- Agriculture, livestock, and waste produce methane and nitrous oxide.
- Industrial processes release fluorinated gases.
- This raises the concentration of GHGs beyond natural levels.
🌍 4. Result: Enhanced Greenhouse Effect
- More GHGs = more heat trapped = higher average global temperatures.
- Leads to global warming, causing:
- Melting glaciers and ice caps
- Rising sea levels
- More extreme weather (storms, droughts, heatwaves)
- Disruption of ecosystems and agriculture
Simple Analogy:
- Think of greenhouse gases like a thicker blanket around Earth — it keeps more heat in, making the planet warmer than it would be naturally.
Summary Table
- Step What Happens
- Sunlight reaches Earth Earth absorbs solar energy
- Earth emits heat Heat radiates back as infrared radiation
- GHGs trap heat Heat is absorbed and re-radiated by gases
- Human emissions increase GHGs More heat trapped → warming
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