13.2 Causes of Climate Change

Activity 1 · Sort the causes

Natural vs human · ~10 min

Place each cause in the correct column.

Causes: burning coal · Earth's orbital cycles · volcanic eruptions · deforestation · solar output · enhanced greenhouse effect · ocean circulation · fossil-fuel transport

Natural	Human

Activity 2 · Rule out the natural causes

Applying geographical understanding · ~15 min

For each natural cause, explain in one sentence why it cannot explain today's warming.

Natural cause	Why it can't explain today's warming
Ice-age (orbital) cycles
Volcanic eruptions
Solar output

Activity 3 · The Pinatubo data

Processing geographical information · ~10 min

Answer using the case study.

How much SO₂ did Pinatubo release, and what was the temperature effect?
Was that effect warming or cooling? Why?
Why doesn't volcanic CO₂ explain the long-term warming?

Activity 4 · Label the carbon cycle

Reading a systems diagram · ~10 min

Complete the sentences about the carbon cycle.

Plants absorb CO₂ through . Oceans act as a . Humans disrupt the cycle by burning and by , which removes sinks. The result is a net in atmospheric CO₂.

One-sentence summary of the disruption:

Activity 5 · The 800,000-year graph

Interpreting a chart · ~12 min

Using the 800,000-year CO₂ record (study page §6), answer.

What is the highest CO₂ reached naturally over 800,000 years?
What is CO₂ today, and when did it start to spike?
Explain why this graph is such strong evidence for a human cause.

Activity 6 · Extended-response plan

Communicating geographical understanding · ~15 min

Plan (dot points only).

Question: “Explain how we know recent climate change is caused by humans rather than natural processes.”

Paragraph	Content (dot points)
Introduction
Rule out natural (cycles, volcanoes)
Human causes (carbon cycle, greenhouse)
Clinching evidence (800,000-yr CO₂)
Conclusion