why climate change happens:

• The Sun sends energy (mostly visible light) to Earth.
• Earth's surface absorbs this energy → internal energy increases → warms up.
• Earth emits this heat as infrared (IR) radiation.
• Greenhouse gases in the atmosphere absorb and re-emit IR radiation.
• This trapped heat leads to global warming → causes climate change.

greenhouse gases:

Main Greenhouse Gases:

• CO₂ – fossil fuels, deforestation
• CH₄ – cows, rice fields, landfills
• H₂O – water vapor (natural amplifier)
• N₂O – fertilizers, factories
• O₃ – tropospheric ozone

How They Work:

• Absorb IR radiation from Earth
• Re-emit it back to Earth → adds more heat
• Raises Earth's internal energy

Effects:

• Global warming
• Melting ice → lower albedo → faster warming
• Extreme weather events
• Ocean heating & acidification
• Changes in ecosystems & rainfall

albedo & surface types:

Albedo:

• Measures reflectivity (0 to 1)
• High albedo (snow/ice) → reflects sunlight → cooler
• Low albedo (dark surfaces) → absorbs sunlight → warmer

Emissivity:

• Dark surfaces: absorb + emit more radiation → heat up fast
• Light surfaces: reflect more → heat up less

Human Impact

Main Sources of GHG Emissions:

• Energy (fossil fuels)
• Transport (cars, planes)
• Agriculture (methane)
• Industry (factories)
• Waste (landfills)

energy types:

Primary Energy: