Year 10 Science · AC9S10U04

Global systems and climate change.

Earth runs on one energy supply, sunlight, shared between the air, the oceans, the land and living things. Change how that energy flows and the climate changes. Australia’s temperature record says the climate is changing now. In this lesson you work out why, the way scientists do: with a model, with evidence, and with an argument that has to survive its critics.

Illustration

The planet’s accounts. Sunlight arrives at 340 W/m² averaged over the globe; about 100 is reflected and 240 absorbed. To stay at a steady temperature, Earth must radiate 240 back out as heat. Right now it radiates slightly less than it absorbs, and the difference is warming the ocean.

The guiding question

Australia has warmed by about 1.5 °C since 1910. What is driving it, and how do we know?

You will build a claim, support it with evidence, defend it against a critic, and write it up. Your answers and notes are saved in this browser.

Atmosphereair, clouds, greenhouse gases

Hydrosphereoceans, ice, water vapour

Biosphereforests, reefs, soils, us

Geosphererock, sand, volcanoes, fossil carbon

Learning intention

We are learning to use models of energy flow between Earth’s spheres to explain patterns of global climate change, and to build and defend an argument from evidence.

Success criteria

1I can use a model of energy flow between the Sun, atmosphere, ocean and land to explain what sets Earth’s temperature.
2I can describe and quantify the pattern of change in Australia’s temperature record.
3I can test candidate causes against evidence, and explain why greenhouse gases fit and the Sun does not.
4I can explain how deep ocean currents form and why they matter for climate.
5I can construct an argument from evidence and answer challenges to it.

Australian Curriculum v9, AC9S10U04: “use models of energy flow between the geosphere, biosphere, hydrosphere and atmosphere to explain patterns of global climate change”

Printable activity

Argue from the data

Plot decade averages of Australian temperature, carbon dioxide and sunspots by hand, write a claim, evidence and reasoning argument, and review a partner’s. The same links are at the end of the lesson.

Activity sheet (PDF) Editable (Word)

How it works: argument-driven inquiry

The model. Run Earth’s energy budget and see what moves the temperature.
The evidence. Read the Bureau of Meteorology record, test three suspects against it, sort the fingerprints, and follow the heat into the deep ocean.
The argument. Choose a claim, pick the evidence that supports it, write the reasoning.
The critic. Answer four challenges with evidence. Weak answers get sent back.
The prediction. If the argument holds, what comes next, and what can be done about it?
The report. Write it up, review a partner’s, and revise.

Scientists argue for a living. Not shouting: claims tested against evidence, in public, where anyone can check. This lesson is that process, in small.

1The model

The energy budget.

Everything about climate starts here. Sunlight comes in; some is reflected, the rest is absorbed and must leave again as heat radiation. The greenhouse effect is the atmosphere sending part of that heat back down. Run the model: change the Sun, the planet’s reflectivity or the greenhouse effect, and watch the budget go out of balance and the temperature move to fix it.

Earth’s energy flows, today

Runnable model

Model

The Sun’s output+0.0% The real Sun varies by about 0.1% over its 11-year cycle.

Reflectivity (albedo)30% More ice and cloud: higher. Dark ocean and forest: lower.

Greenhouse effect78% The share of the surface’s heat radiation the air absorbs. More CO₂: higher.

Surface

Budget

Today’s budget: 340 W/m² in from the Sun, 100 reflected, 240 absorbed and 240 radiated back to space, with a small imbalance of about 0.7 W/m² warming the ocean. Move a dial.

Which sphere does what? Press one.

About the model. The flows are the IPCC’s global averages (AR6, 2021), rounded. The temperature comes from a one-layer greenhouse model: good for direction and rough size, but it leaves out the feedbacks (water vapour, ice, clouds) that roughly triple the direct effect of extra CO₂ in the real climate. Without any greenhouse effect the model gives about −18 °C, which is also what the real planet would be.

Key idea

Temperature is set by the balance. Anything that changes energy in or energy out changes the temperature until the two match again.

A brighter Sun, less ice, or more greenhouse gas all push the same way. The question for the rest of the lesson is which of them has actually changed, and by how much.

Set the Sun to +1%. By how much does the surface warm once the planet adjusts?

Which flow does adding carbon dioxide change most directly?

Notebook: predictions from the model

If the temperature record shows a rise of 1.5 °C over a century, what does the model say could have caused it? List every candidate the dials allow, and how big a change in each would be needed.

Where does the stored energy go while the planet is out of balance? Why does that matter for how fast the air warms?

2The evidence

The record.

The Bureau of Meteorology keeps a reference temperature record for Australia from 1910, built from 112 long-running stations checked against each other, with the big-city sites left out of the national trend (ACORN-SAT). Each bar is one year’s difference from the 1961 to 1990 average: an anomaly. Read it before you explain it.

Australian annual mean temperature anomaly, 1910 to 2025

Data

Hover over or tap a year, or select the chart and use the arrow keys (hold shift to move ten years).

Data: Bureau of Meteorology, Australian climate variability and change time series: ACORN-SAT annual mean temperature anomaly (1910 to 2025) and Australian-region sea surface temperature anomaly (1900 to 2025). Fetched October 2026.

Three things to explain

A rise of about 1.5 °C over the century. A rise that gets steeper after 1960. And a sea that has warmed too, by about 1 °C.

Any explanation has to fit all three, and the year-to-year noise on top of them. Single hot or cold years prove little; the trend is the evidence.

Why show a ten-year average as well as the yearly values?

Sea surface temperatures have risen along with land temperatures. Why does that matter for the argument?

Notebook: notice and wonder

Describe the pattern in the record with numbers: the coldest and warmest decades, the size of the change, and when it steepened.

What is one question this record makes you ask?

2The evidence

The suspects.

The energy budget allows three ways to warm a planet: a brighter Sun, less reflection, or a stronger greenhouse effect. Here are the three candidates people usually name, each on its own axis, lined up under the temperature record. A real cause has to match the shape of the rise, not just point the right way.

Line-up: the record on top, one suspect below

Data

Hover over or tap either chart to read the same year on both. Each chart has its own axis; they share only the years.

Your verdict on the Sun. Does the sunspot record match the shape of the temperature rise?

Yes, it rises in the same shape. It explains the short wiggles but not the long rise. No: it cycles up and down with no upward trend, and recent cycles are weaker.

Sunspots: SILSO, Royal Observatory of Belgium, yearly means. Eruptions: Agung 1963, El Chichón 1982, Pinatubo 1991. CO₂: Law Dome ice core (Etheridge et al.) to 1975, then Kennaook / Cape Grim yearly means (CSIRO and the Bureau of Meteorology).

Key idea

Matching the shape is the first test. Only one suspect passes it.

Correlation is not proof on its own. The next screen adds the second test: fingerprints that only one cause can leave.

Which statement about the line-up is correct?

Notebook: the case so far

For each suspect, write one sentence that says whether it matches and what in the data tells you.

2The evidence

Fingerprints.

Warming leaves marks in every sphere: on the sea, the ice, the reef, the species that move. Most of those marks would appear whatever was doing the warming. A few are different. They are the fingerprints: patterns one cause produces and the others cannot. Sort the seven cards.

Seven observed changes, two piles

Card sort

Sources: BoM and CSIRO State of the Climate 2024; IPCC AR6; NSIDC Sea Ice Index; Australian Institute of Marine Science; Institute for Marine and Antarctic Studies; Harries et al. (2001) Nature 410, 355 to 357. Details in the teacher notes.

Key idea

A cooling stratosphere above a warming surface is the signature of greenhouse gases. A brighter Sun would warm both.

Greenhouse gases trap heat in the lower atmosphere and, by radiating more effectively from high up, cool the layer above. Satellites have watched exactly that since 1979. The second fingerprint is direct: less heat escaping to space at the gases’ own wavelengths.

If the Sun were driving the warming, what would the stratosphere be doing?

Notebook: which evidence discriminates?

Explain in your own words why bleached coral is evidence of warming but not of its cause, while a cooling stratosphere is evidence of the cause.

2The evidence

The ocean’s conveyor.

About 90% of the extra heat from the energy imbalance is in the ocean, not the air. Where it goes next depends on the slowest, largest current on Earth: the overturning circulation, driven by dense water sinking at the poles. Its biggest engine room is on Australia’s doorstep.

Why water sinks: the density tank

Model

Temperature2.0 °C

Salinity34.7 g/kg

Presets

Where it goes: the overturning circulation

Map, simplified

The map is a simplified sketch of a circulation that in reality has many branches. A parcel of water takes about a thousand years to complete the loop.

On Australia’s doorstep

The densest water on Earth forms in winter on the Antarctic shelf south of Australia, at Adélie Land and Cape Darnley among other places, when growing sea ice leaves its salt behind. It sinks into the Australian Antarctic Basin and spreads along the sea floor, ventilating the deep ocean and carrying heat and carbon down with it. CSIRO and university oceanographers reported in 2023 that this abyssal overturning in the basin has slowed by about 30% since the 1990s, because meltwater from Antarctica’s ice is freshening the shelf water so it no longer sinks as readily. Try the ice-shelf meltwater preset in the tank to see why.

Which water sinks to the bottom of the tank?

Why would melting Antarctic ice slow the overturning?

Notebook: energy and the deep ocean

The overturning carries heat and carbon from the surface into the deep ocean. If it slows, what happens to the heat and carbon that would have gone down? Connect this to the energy budget.

3The argument

Build your argument.

A scientific argument has three parts: a claim, the evidence, and the reasoning that connects them. The evidence cards below were collected as you worked. Choose a claim, pick the cards that support it, and the lesson will tell you whether they agree. Then meet the critic.

Claim, evidence, reasoning

1Claim

Which claim will you argue for? Pick the one you think the evidence best supports.

2Evidence

Tick the cards that support your claim. Cards you have not collected yet are greyed out; go back to that screen to earn them.

3Reasoning

Explain how the evidence supports the claim. Take each card in turn and say what it rules in or rules out.

Starters: “The record shows … which means …” · “If the Sun were the cause we would expect … but …” · “Carbon dioxide fits because … and because …” · “The strongest evidence is … because it could not be produced by …”

4The critic

The argumentation session

In a real argumentation session you present your argument to another group and they try to break it. Here a critic raises the four objections scientists hear most. Choose the response that answers each one with evidence. One try each.

The climate has always changed. Ice ages came and went long before people. Why blame us now?

It is the Sun. The Sun drives the climate, everyone knows that.

Carbon dioxide is 0.04% of the air. Something that small cannot possibly matter.

The thermometers are in cities. Cities have grown, so of course they read warmer.

Notebook: after the critic

Which challenge was hardest to answer? What would you add to your argument or your evidence now?

5Predict and respond

Predict and respond.

If the argument is right, the model predicts the future: the more greenhouse gas, the more warming. The IPCC runs that prediction for five emissions scenarios. Choose one to see what it means for Australia, then sort the responses.

Warming by 2081 to 2100, relative to 1850 to 1900

IPCC AR6

Tap a pathway (or select it and press Enter). The dot is the best estimate; the line is the very likely range (90%). Warming so far: 1.1 °C for 2011 to 2020.

Responses: reduce the warming, or live with it?

Projections: IPCC, Climate Change 2021: The Physical Science Basis, Summary for Policymakers, Table SPM.1. Australian impacts: IPCC AR6 regional fact sheet for Australasia and BoM and CSIRO State of the Climate 2024, summarised.

A note on quantum computers (elaboration AC9S10U04)

Weather and climate models divide the planet into a grid and solve the physics in every cell, billions of times. The Bureau’s forecasts run on conventional supercomputers. Quantum computers, which handle certain kinds of calculation in ways ordinary computers cannot, are being studied as a way to run parts of these models faster or at finer detail, but in 2026 that work is research: no operational weather or climate model runs on a quantum computer, and it is not yet clear which parts of the problem they will help with. When you read a claim about quantum computing and the climate, ask the same question as for any claim: what is the evidence, and who has tested it?

What is the main difference between the five pathways?

Notebook: prediction

Pick one pathway. Using the energy budget, explain in two or three sentences why it leads to the warming shown, and name one strategy that would move the world to a lower pathway.

6Report and review

Report and review.

The last steps of argument-driven inquiry: write the argument up, have it reviewed by someone who does not know whose it is, and revise. Then the exit check.

Your report

Write your argument in full: the claim, each piece of evidence with its source, the reasoning that connects them, and how you answered the critic. Use numbers from the record.

Check it against the review criteria before you hand it over

The claim is stated in one clear sentence.
At least three pieces of evidence are given, each with its source and a number.
The reasoning explains how each piece of evidence supports the claim, using the energy budget.
At least one alternative cause is considered and ruled out with evidence.
It uses the terms correctly: energy budget, greenhouse effect, anomaly, fingerprint.

Peer review, double blind

Swap reports without names. Review your partner’s against the five criteria above, write one thing it does well and one thing it must fix, and hand it back. Then revise your own report using the review you received. The printable sheet at the end of this screen has the review form.

Exit check

One try each. Your results, with the critic’s four challenges, show which parts of the lesson to look at again.

In the energy budget, why does adding greenhouse gas warm the surface?

Which statement best describes Australia’s temperature record since 1910?

What makes greenhouse gases a better explanation than the Sun?

What drives Antarctic Bottom Water to sink?

A student’s argument that greenhouse gases cause the warming uses only these cards: sea level is rising, reefs are bleaching, sea ice is shrinking. What is the weakness?

Offline activity

Argue from the data

Plot decade averages of Australian temperature, carbon dioxide and sunspots by hand, write a claim, evidence and reasoning argument, and review a partner’s with the peer review sheet.

Activity sheet (PDF) Editable (Word)

For teachers

Curriculum

Australian Curriculum: Science, Version 9. Year 10, Science Understanding, Earth and space sciences.

AC9S10U04: use models of energy flow between the geosphere, biosphere, hydrosphere and atmosphere to explain patterns of global climate change

Elaborations, as ACARA lists them, and where the lesson meets each:

examining the role of radiation from the sun and how its interactions with the atmosphere, ocean and land are the foundation for the global climate system: screen 2, the energy budget.
investigating indicators of climate change such as changes in ocean and atmospheric temperatures, sea levels, biodiversity, species distribution, permafrost and sea ice: screens 3 and 5.
identifying changes in global climate over time, exploring visualisations and using simulations to explore why energy balances have changed: screens 2 to 4.
examining the factors, including energy, that drive deep ocean currents, their role in regulating global climate and their effects on marine life: screen 6.
investigating how quantum computers enhance modelling of complex weather and climate systems: the note on screen 8, deliberately sober.
predicting changes to the Earth system and identifying strategies designed to reduce climate change or mitigate its effects: screen 8.

From the Year 10 achievement standard:

They describe trends in patterns of global climate change and identify causal factors. [...] They analyse and connect a variety of data and information to identify and explain patterns, trends, relationships and anomalies. They evaluate the validity and reproducibility of methods, and the validity of conclusions and claims. They construct logical arguments based on analysis of a variety of evidence to support conclusions and evaluate claims.

All quoted from ACARA’s Science scope and sequence F–10 and curriculum content 7–10 documents, Version 9.0.

How the lesson is taught

The lesson follows argument-driven inquiry (Sampson, Grooms and Walker, 2011): a guiding question, a model to think with, evidence to generate and read, a tentative argument in claim, evidence and reasoning form, an argumentation session in which the argument is challenged, then a written report, double-blind peer review and revision.

Task and question (screen 1), model (screen 2), evidence (screens 3 to 6), tentative argument and argumentation session (screen 7), prediction (screen 8), report, review and revision (screen 9).
The evidence cards on screen 7 are collected automatically as students work the evidence screens; a student who skips a screen has fewer cards, and the lesson tells them where to earn the missing ones.
The claim is not marked. The coherence check only tells students when their chosen cards contradict their claim, or when none of their cards bears on the cause. That is the ADI move: the evidence disciplines the claim.
The critic’s four challenges use the lesson’s one-try checks and count in the exit results. Run them again as a live argumentation session in class: one group presents, the others play the critic.

Allow three lessons: screens 1 to 3, then 4 to 6, then 7 to 9, with the peer review in class. The report is the main assessment piece; the review criteria on screen 9 are the rubric.

About the data and the models

Temperature: Bureau of Meteorology ACORN-SAT annual anomalies for Australia, 1910 to 2025, and Australian-region sea surface temperature anomalies, 1900 to 2025, both relative to 1961 to 1990, from the Bureau’s climate change time series pages, fetched October 2026. The decade averages in the table are computed from the annual values; the Bureau’s stated warming of about 1.5 °C since 1910 is a linear trend.
Sunspots: SILSO yearly mean total sunspot number, version 2.0. Carbon dioxide: Law Dome ice core (Etheridge et al.), interpolated between decadal values to 1975, then Cape Grim yearly means from the carbon cycle lesson’s data (CSIRO and the Bureau); 1976 is interpolated because measurements began in May.
The energy budget flows are the IPCC AR6 Figure 7.2 values (Wild et al. 2015, 2019), rounded: 340 in, 100 reflected, 80 absorbed by the atmosphere and 160 by the surface, 398 emitted by the surface, 342 returned by the atmosphere, 239 out to space, 21 sensible and 82 latent heat, with an imbalance of about 0.7 W/m² (0.71 for 2005 to 2015 from CERES; the IPCC gives 0.79 for 2006 to 2018). The temperature model is a one-layer leaky greenhouse: surface temperature equals the effective temperature times (2 ÷ (2 − ε))^¼, with ε the share of surface heat radiation the atmosphere absorbs. At ε = 0.78 it gives 15 °C, and 1% more sunlight gives +0.7 °C. It has no feedbacks, so a given change in ε understates the real response by roughly a factor of three; the screen says so.
The density tank uses the UNESCO 1983 equation of state at surface pressure. The conveyor map is a sketch of the overturning circulation on an equirectangular map centred on 100°E, with Antarctic Bottom Water formation sites at the Weddell Sea, Ross Sea, Adélie Land and Cape Darnley.
The Bureau and CSIRO’s own conclusion, State of the Climate 2024: “The primary and unequivocal driver of climate change since the 1850−1900 period is the accumulation of greenhouse gases in the atmosphere.” Australia has warmed 1.51 ± 0.23 °C since 1910, sea surface temperatures 1.08 °C since 1900.
ACORN-SAT uses 112 stations; the Bureau excludes the four sites it defines as urban (Sydney, Melbourne, Adelaide and Hobart) from the national trend and averages.
Fingerprint cards: sea level and ocean heat from BoM and CSIRO State of the Climate 2024 and IPCC AR6; Antarctic sea ice from NSIDC (record low minimum February 2023 and record low maximum September 2023); bleaching years from AIMS; the urchin from IMAS; stratospheric cooling from NASA and IPCC AR6; the spectral fingerprint from Harries et al. (2001).
Volcanoes: NASA Earth Observatory gives Pinatubo’s cooling as about 0.6 °C for almost two years; the USGS puts volcanic carbon dioxide at less than 1% of human emissions.
Scenarios: IPCC AR6 WG1 Table SPM.1 best estimates and very likely ranges for 2081 to 2100 relative to 1850 to 1900. The Australian consequences are summarised from the AR6 Australasia regional fact sheet and State of the Climate 2024, not quoted.
Quantum computing: Tennie and Palmer (2023) in the Bulletin of the American Meteorological Society judge quantum computers “unlikely to replace classical computers for NWP or climate prediction in the foreseeable future”; Schwabe et al. (2025) describe the research as “still in their infancy”.

Answers at a glance

Energy model: Sun +1% gives about +0.7 °C; albedo 30% to 29% about +1 °C; greenhouse 78% to 80% about +1.2 °C. No greenhouse effect: about −18 °C.
Record: warmest year 2019 (+1.51 °C); 1910s −0.45 °C, 2010s +0.86 °C; sea surface about +1 °C since 1900.
Suspects: Sun, no; volcanoes, short dips only; carbon dioxide, matches. Fingerprints: five “any cause”, two “greenhouse” (stratosphere, spectrum).
Tank: cold and salty sinks; the Antarctic shelf preset sinks, the meltwater preset floats. Strategies: six reduce, six adapt.
Exit check: x1 reduces heat escaping until the surface warms; x2 about 1.5 °C, steeper after 1960; x3 shape plus fingerprints; x4 sea ice leaves cold salty water; x5 the cards show warming but not cause. Critic: c1 natural drivers tested and flat; c2 Sun checked first; c3 small amounts matter, satellites see it; c4 stations away from cities, the sea has none.

Saved progress

Answers, cards and notes are saved only in this browser on this device. Nothing is sent anywhere.

Sources

ACARA: Australian Curriculum Version 9, Science, Year 10
Bureau of Meteorology: Australian climate variability and change, time series (ACORN-SAT annual mean temperature anomaly; sea surface temperature anomaly; south-west WA April to October rainfall)
Bureau of Meteorology and CSIRO: State of the Climate 2024
SILSO, Royal Observatory of Belgium: sunspot number data files
CSIRO: Cape Grim greenhouse gas data and Etheridge et al. (1996), Law Dome ice core CO₂
IPCC AR6 WG1 Chapter 7: the Earth’s energy budget, climate feedbacks and climate sensitivity and Summary for Policymakers
Wild et al. (2015): The energy balance over land and oceans, Climate Dynamics
NASA Earth Observatory: Climate and Earth’s energy budget and NASA: Is the Sun causing global warming?
NOAA Climate.gov: Climate change: incoming sunlight
NASA Earth Observatory: global effects of Mount Pinatubo and USGS Volcano Hazards Program
Harries et al. (2001): Increases in greenhouse forcing inferred from the outgoing longwave radiation spectra of the Earth in 1970 and 1997, Nature
NSIDC: Sea Ice Today
Australian Institute of Marine Science: coral bleaching on the Great Barrier Reef
Institute for Marine and Antarctic Studies: long-spined sea urchin range extension
Gunn, Rintoul, England and Bowen (2023): Recent reduced abyssal overturning and ventilation in the Australian Antarctic Basin, Nature Climate Change
NOAA Ocean Service: the global conveyor belt
Tennie and Palmer (2023): Quantum computers for weather and climate prediction: the good, the bad and the noisy, BAMS and Schwabe et al. (2025): Opportunities and challenges of quantum computing for climate modelling, Environmental Data Science
Sampson, V., Grooms, J. and Walker, J. P. (2011). Argument-driven inquiry as a way to help students learn how to participate in scientific argumentation and craft written arguments. Science Education, 95(2), 217 to 257.