Anthropogenic Causes of Climate Change

What is the greenhouse effect?

A process where greenhouse gases absorb long-wave thermal radiation, making Earth much warmer than without them.

What would Earth’s average temperature be without greenhouse gases?

Below 0ºC.

Outline the steps of the greenhouse effect.

1. What does the sun emit?

Short-wave radiation

2. Where does the short-wave radiation pass through?

The atmosphere.

3. What does the absorbed sunlight do?

Warm the Earth’s surface.

4. What is emitted by the Earth’s surface?

Long-wave radiaiton.

5. What does longwave radiation emitted by the earth absorbed by?

Greenhouse gases, making the atmosphere warmer

Which two greenhouse gases are most significant?

Methane and carbon dioxide.

Why aren’t other abundant gases like oxygen and nitrogen greenhouse gases?

They don’t absorb long-wave radiation.

Name two natural sources of CO₂ emissions.

Cell respiration and natural forest fires.

What causes the enhanced greenhouse effect?

Combustion of fossil fuels, biomass burning, forest fires, and deforestation.

What are two major methane sources?

Melting permafrost (methanogens) and ruminant guts in cattle farming.

What role does water vapour play in warming?

It absorbs radiation, reflects heat energy back to Earth, and retains heat in clouds.

When does temperature decrease faster at night?

When there are no heat-retaining clouds.