Lesson Y9-U03-L07

Y9-U03-L07 The Greenhouse Effect and the Carbon Story Quiz: KS3 Geography, Unit 15

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson Y9-U03-L07, The Greenhouse Effect and the Carbon Story: 20 multiple choice questions for the KS3 Geography (National Curriculum), Unit 15: Year 9: Weather, Climate and a Changing Atmosphere, written with Revision Ninja.

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The 20 questions

  1. What does the greenhouse effect do to heat leaving the Earth?

    • It turns the heat into sunlight that falls back onto the sea.
    • It stops the Earth's surface from absorbing any sunlight at all.
    • It sends all of it straight out into space at once.
    • It absorbs some of it and sends some back towards the surface.

  2. Without natural greenhouse gases, what would Earth's average temperature be?

    • About minus 50 degrees Celsius.
    • About plus 33 degrees Celsius.
    • About plus 15 degrees Celsius.
    • About minus 18 degrees Celsius.

  3. Which gas is the main greenhouse gas that humans add to the air?

    • Nitrogen, which makes up most of the air we breathe.
    • Carbon dioxide.
    • Argon, a noble gas that is found in trace amounts in the air.
    • Oxygen, which plants release during photosynthesis.

  4. Which gas traps more heat per molecule than carbon dioxide does?

    • Oxygen.
    • Argon.
    • Nitrogen.
    • Methane.

  5. About what share of UK greenhouse gas emissions in 2022 was carbon dioxide?

    • About 50 percent.
    • About 14 percent.
    • About 79 percent.
    • About 5 percent.

  6. Why does methane matter, even though it is a small share of emissions?

    • Each methane molecule traps far more heat than a carbon dioxide molecule.
    • It makes up most of the air we breathe every day, so even small changes in it matter a lot.
    • It falls to the ground and stops all rainfall.
    • It is the only gas in the air that absorbs sunlight, which is why it keeps the surface warm.

  7. Where was the carbon in fossil fuels before humans burnt them?

    • Kept in the atmosphere as fresh air.
    • Stored in clouds above the sea.
    • Locked underground for millions of years.
    • Floating in the ocean as ice.

  8. Which human activity adds the most carbon dioxide to the air?

    • Planting new trees in city parks each spring to shade the streets and pavements.
    • Recycling paper and glass bottles at home and at school every single week.
    • Burning fossil fuels for power, transport and industry.
    • Drinking water from a tap in the home.

  9. Why does cutting down forests add to the greenhouse effect?

    • Trees produce cold air that cools the planet down.
    • Trees release helium into the air, which stops heat from escaping through the atmosphere.
    • Trees block sunlight, so the Earth cannot warm up.
    • Fewer trees absorb carbon dioxide, so more of it stays in the air.

  10. On the CO2 and temperature graph, what was the carbon dioxide level in 2020?

    • About 317 parts per million.
    • About 98 parts per million.
    • About 414 parts per million.
    • About 369 parts per million.

  11. From 1960 to 2020, how did the carbon dioxide level change on the graph?

    • It rose from about 317 to about 414 parts per million.
    • It fell from about 414 to about 317 parts per million.
    • It stayed at about 317 parts per million throughout.
    • It rose from about 50 to about 100 parts per million.

  12. Which statement best describes the link shown on the graph?

    • Carbon dioxide and temperature rise together, so they correlate.
    • Carbon dioxide and temperature are both measured in degrees.
    • Carbon dioxide falls as temperature rises, so they are unrelated.
    • Temperature stays flat while carbon dioxide grows very large.

  13. The temperature line is scaled up 100 times. What does a reading of 98 mean?

    • About 0.098 degrees Celsius of warming.
    • About 9.8 degrees Celsius of warming.
    • About 98 degrees Celsius of warming.
    • About 0.98 degrees Celsius of warming.

  14. A student says 'the graph proves carbon dioxide causes warming'. What is the best correction?

    • The graph shows nothing useful, because two lines can never rise together in any real data set at all.
    • The graph shows carbon dioxide causes cold weather in the UK.
    • Correlation alone does not prove cause; the heat-trapping physics explains why carbon dioxide drives warming.
    • The graph proves the cause completely, so no physics is needed and no other evidence is worth checking at all.

  15. In the greenhouse effect, what happens right after the Earth's surface warms up?

    • It creates a new ocean above the atmosphere.
    • It turns sunlight into carbon dioxide in the sky.
    • It stops sunlight from ever reaching the surface again.
    • It gives off long-wave heat energy back towards space.

  16. Why is the greenhouse effect described as natural?

    • It has always existed and keeps Earth warm enough for life.
    • It was invented by humans in the twentieth century.
    • It only happens inside factories and power stations.
    • It stops the Sun from shining on the Earth at all.

  17. Which pair correctly describes the natural and enhanced greenhouse effects?

    • Natural is caused by factories and power stations; enhanced is caused by the Sun's changing output.
    • Natural and enhanced both cool the planet down over time.
    • Natural traps no heat at all; enhanced traps all of the heat.
    • Natural keeps Earth warm for life; enhanced adds extra gases that trap more heat.

  18. Carbon dioxide makes up about 79 percent of UK emissions. Why can't we conclude that methane is unimportant?

    • Because percentages measure amounts, not warming strength, and methane traps far more heat per molecule.
    • Because methane is the only gas that is not in the atmosphere at all, so it cannot warm anything.
    • Because methane makes up 79 percent of the air we breathe, so it must be the main warming gas overall.
    • Because the chart shows methane as bigger than carbon dioxide.

  19. Which is the strongest evidence that humans are causing the warming?

    • A single cold winter in the UK, which proves that the global climate has in fact stopped warming.
    • Rising carbon dioxide that correlates with warming, plus a physical mechanism that explains it.
    • The Sun getting brighter in every single decade since records began, which explains all the recent warming.
    • One graph line that rises for only a single year.

  20. Which judgement best evaluates whether rising carbon dioxide is causing the warming?

    • It is impossible to say anything, since no evidence can ever be trusted.
    • It is certainly not true, because the Sun is the only heat source for Earth.
    • It is only true for the UK, because the rest of the world is unaffected.
    • It is very likely: the data correlate and heat-trapping physics explains the mechanism.

All KS3 Geography quizzes