HSC Geography › Human–Environment Interactions › 13.2

# Activity Materials — Causes of Climate Change

NSW Stage 6 Geography (2022) · Student worksheet
Name: Class: Date:

## 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.

1. How much SO₂ did Pinatubo release, and what was the temperature effect?
2. Was that effect warming or cooling? Why?
3. 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.

1. What is the highest CO₂ reached naturally over 800,000 years?
2. What is CO₂ today, and when did it start to spike?
3. 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 |

Reputable sources: NASA — evidence · USGS volcanoes · NOAA CO₂
Rose Bay Secondary College · HSC Geography · Human–Environment Interactions — Activities (13.2) · NESA Stage 6 (2022) · HSC 2026
Aligned to the NESA Geography Stage 6 Syllabus (2022); model answers in the teacher lesson plan.