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Year 9 Science Maths English Cross-Curricular Project

Analysing Climate Change Data

Examine real temperature data, understand the science, and write an evidence-based analytical essay.

Subjects Connected

Science

Greenhouse effect, carbon cycle, human impact on climate systems

Maths

Statistics, line graphs, trend analysis, standard deviation introduction

English

Analytical essay writing, evidence-based argument, evaluating sources

Inspired by Finnish phenomenon-based learning and IB Approaches to Learning: critical thinking with real data.

The Big Question

"What does the data actually tell us about climate change, and how confident can we be in our conclusions?"

In this project, you will work with real climate data, apply statistical methods, understand the underlying science, and write an analytical essay that uses evidence responsibly.

Science: The Greenhouse Effect and Human Impact

The Greenhouse Effect

The greenhouse effect is a natural process that warms the Earth. Without it, Earth's average temperature would be about -18°C — far too cold for life. Here is how it works:

1

Sunlight passes through the atmosphere and warms the Earth's surface.

2

The Earth's surface radiates infrared heat back toward space.

3

Greenhouse gases (CO2, methane, water vapour) in the atmosphere absorb and re-emit some of this heat, trapping it near Earth.

4

More greenhouse gases = more heat trapped = enhanced greenhouse effect = rising temperatures.

The Carbon Cycle and Human Impact

Carbon naturally cycles between the atmosphere, oceans, soil, and living organisms. The problem is that humans are adding carbon to the atmosphere much faster than natural processes can remove it:

Sources (Adding CO2)

  • Burning fossil fuels (coal, oil, gas)
  • Deforestation
  • Industrial processes (cement, steel)
  • Agriculture (methane from livestock)

Sinks (Removing CO2)

  • Forests (photosynthesis)
  • Oceans (dissolving CO2)
  • Soil organisms
  • Weathering of rocks (very slow)

Key Data Point

Atmospheric CO2 has risen from about 280 ppm (parts per million) in pre-industrial times to over 420 ppm today — a 50% increase. This is the highest level in at least 800,000 years based on ice core data.

Think About It (Claim-Support-Question)

Consider the claim: "Human activity is the primary cause of recent climate change."

  • Claim: What position does this statement take?
  • Support: What evidence from the science section supports this?
  • Question: What additional evidence would strengthen or weaken this claim?

Maths: Analysing Real Temperature Data

Historical Temperature Anomalies

A temperature anomaly is the difference between the observed temperature and a long-term average (baseline). Positive values mean warmer than average; negative values mean cooler. The data below shows global temperature anomalies relative to the 1951-1980 average (source: NASA GISS).

Decade 1920s 1940s 1960s 1980s 2000s 2020s
Average Anomaly (°C) -0.18 +0.03 -0.02 +0.18 +0.62 +1.15

Year-by-Year Data (Selected Years)

Year 1925 1945 1965 1975 1985 1995 2005 2015 2024
Anomaly (°C) -0.18 +0.09 -0.11 -0.01 +0.12 +0.45 +0.67 +0.87 +1.29

Global Temperature Anomaly by Decade (°C relative to 1951-1980)

1920s -0.18
1940s +0.03
1960s -0.02
1980s +0.18
2000s +0.62
2020s +1.15

Source: Based on NASA GISS data. Baseline: 1951-1980 average.

Calculating the Trend

To identify a trend, we can calculate the rate of change between two data points:

Worked Example: Rate of Temperature Change

From 1925 to 2024:

Change in anomaly = +1.29 - (-0.18) = +1.47°C

Time period = 2024 - 1925 = 99 years

Rate of change = 1.47 ÷ 99 = +0.0148°C per year

Or approximately +0.15°C per decade.

But is this rate constant? Look at the data — the warming is clearly accelerating in recent decades.

Introduction to Standard Deviation

Standard deviation (SD) measures how spread out data is from the average. A small SD means data points are close to the mean; a large SD means they are spread out.

Simplified Example

Consider these 5 year-by-year anomalies: +0.45, +0.52, +0.48, +0.50, +0.55

Step 1: Find the mean = (0.45 + 0.52 + 0.48 + 0.50 + 0.55) ÷ 5 = 0.50

Step 2: Find each difference from the mean: -0.05, +0.02, -0.02, 0.00, +0.05

Step 3: Square each difference: 0.0025, 0.0004, 0.0004, 0.0000, 0.0025

Step 4: Mean of squares = 0.0058 ÷ 5 = 0.00116

Step 5: Square root = SD ≈ 0.034°C

This small SD tells us these values are very consistent — the warming trend for this period is reliable.

Think About It (Red Light, Yellow Light)

Consider these claims about the data:

  • Red light (unreliable): "The 1960s were cooler than the 1940s, so there is no warming trend."
  • Yellow light (partial truth): "Temperatures have always changed naturally."
  • Green light (reliable): "The data shows a clear acceleration in warming since 1980."

Why is cherry-picking individual decades misleading? Why does the overall trend matter more?

English: Writing an Evidence-Based Analytical Essay

An analytical essay examines evidence, evaluates it critically, and presents a well-reasoned argument. Unlike a persuasive essay (which tries to convince), an analytical essay aims to explain and evaluate.

Essay Structure

1. Introduction

State your thesis (central argument). Provide brief context. Outline what the essay will cover.

Example thesis: "Analysis of global temperature data from 1925 to 2024 reveals a clear and accelerating warming trend, strongly correlated with rising CO2 levels."

2. Body Paragraph 1: Present the Data

Describe the data set. What does it show? Reference specific numbers, trends, and time periods. Include a graph reference.

3. Body Paragraph 2: The Science

Explain the scientific mechanism (greenhouse effect, carbon cycle) that connects CO2 levels to temperature changes.

4. Body Paragraph 3: Evaluate the Evidence

Discuss strengths and limitations. How reliable is the data? What are potential sources of error? Acknowledge complexity.

5. Conclusion

Restate your thesis in light of the evidence. Identify remaining questions. Suggest implications.

Academic Language Toolkit

Presenting Evidence:

  • "The data indicates that..."
  • "As shown in Figure 1..."
  • "This is supported by..."
  • "The trend demonstrates..."

Evaluating Critically:

  • "However, it should be noted that..."
  • "A limitation of this data is..."
  • "While the correlation is strong, correlation does not prove causation..."
  • "To what extent can we conclude..."

Think About It (Tug of War)

Consider the tension: "To what extent should we trust this data?"

Pull toward trusting it:

  • Data comes from multiple independent sources (NASA, NOAA, Met Office)
  • 100+ years of consistent measurement
  • Peer-reviewed by thousands of scientists

Pull toward questioning it:

  • Older measurements may be less accurate
  • Urban heat islands can affect local readings
  • Natural climate variation exists alongside human impact

Where does the balance fall? How do scientists address these limitations?

Key Vocabulary

Greenhouse Effect

The trapping of heat in Earth's atmosphere by greenhouse gases (CO2, methane, water vapour).

Carbon Cycle

The natural circulation of carbon between atmosphere, oceans, soil, and living organisms.

Temperature Anomaly

The difference between observed temperature and a long-term average baseline. Shows whether a period is warmer or cooler than normal.

Standard Deviation

A measure of how spread out data is from the mean. Low SD = data is consistent. High SD = data is variable.

Correlation

When two variables change together (e.g. CO2 and temperature both rise). Does not automatically prove one causes the other.

Analytical Writing

Writing that examines evidence, identifies patterns, evaluates strengths and weaknesses, and presents a reasoned conclusion.

Activities & Investigations

1

Graph the Data (Maths)

Using the year-by-year data table, plot a line graph showing temperature anomalies from 1925 to 2024. Label axes correctly. Draw a line of best fit. Describe the trend in mathematical terms (rate of change).

2

Compare Periods (Maths)

Calculate the rate of change for three separate periods: 1925-1965, 1965-1995, and 1995-2024. What do you notice about how the rate of warming has changed over time? Is the warming linear or accelerating?

3

CO2 and Temperature Comparison (Science + Maths)

Research atmospheric CO2 levels for the same time periods. Plot both CO2 and temperature on the same graph (dual-axis). Is there a correlation? Discuss why correlation alone does not prove causation — what additional evidence supports the link?

4

Write Your Analytical Essay (English + All Subjects)

Write a 600-800 word evidence-based analytical essay addressing: "What does the temperature data tell us about climate change, and how reliable is this evidence?" Use specific data, reference your graphs, discuss the science, and evaluate the limitations.

Knowledge Check

Test your understanding across all three subjects.

Question 1 Maths

The temperature anomaly was -0.18°C in 1925 and +1.29°C in 2024. What is the total change?

Question 2 Science

Which greenhouse gas is most increased by burning fossil fuels?

Question 3 Maths

Looking at the decade data, the anomaly went from +0.18°C (1980s) to +1.15°C (2020s) in 40 years. What is the rate of change per decade?

Question 4 English / Critical Thinking

Someone says: "It was cold last winter, so climate change is not real." Why is this argument flawed?

Question 5 Science

In the greenhouse effect, what role do greenhouse gases play?

Key Concepts Summary