Grade 7 · Science · Unit 12 of 12
Changing Climate
Greenhouse gases and solutions
What your child practises
The greenhouse effect, evidence of climate change (real CO₂ measurements, glaciers, ice cores), human causes, actions that help, and the value of Indigenous knowledge of the land.
Ontario Curriculum expectation: E1.2, E2.7, E2.8 · the greenhouse effect, greenhouse gas sources, and renewable and non-renewable energy
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
Put the steps of the greenhouse effect in order.
- ♨️The warm surface gives off heat (infrared energy)
- 🌫️Greenhouse gases absorb some heat and send part back down
- 🌍Land and oceans absorb the light and warm up
- ☀️Sunlight passes through the atmosphere to Earth's surface
Show answer
Sunlight passes through the atmosphere to Earth's surface → Land and oceans absorb the light and warm up → The warm surface gives off heat (infrared energy) → Greenhouse gases absorb some heat and send part back down
Hint: Energy arrives as sunlight, warms the surface, leaves as heat, and some of that heat is held in by greenhouse gases.
Question 2
What is the greenhouse effect?
🌍- All of Earth's heat escaping straight into space
- Gases in the atmosphere trap some of Earth's heat, keeping the planet warm
- A hole in the ozone layer letting in more sunlight
- Heat from greenhouses on farms warming the planet
Show answer
Gases in the atmosphere trap some of Earth's heat, keeping the planet warm
Hint: Gases like carbon dioxide and methane act a bit like a blanket around Earth.
Question 3
How do ice cores help scientists study climates from long ago?
🧊- The ice shows what animals ate
- Ice cores record the history of earthquakes only
- The ice is used to cool lab computers
- Air bubbles trapped in the ice show what the atmosphere was like in the past
Show answer
Air bubbles trapped in the ice show what the atmosphere was like in the past
Hint: Ice sheets build up layer by layer, sealing in tiny samples of old air. Some cores go back 800,000 years.
Question 4
Methane is a powerful greenhouse gas. Which is a major source of it?
- wind turbines
- landfills and cattle
- growing trees
- solar panels
Show answer
landfills and cattle
Hint: Methane comes from rotting waste without oxygen, digestion in cows, and natural gas leaks.
Question 5
Which of these is a fossil fuel?
- coal
- sunlight
- flowing water
- wind
Show answer
coal
Hint: Coal, oil and natural gas formed over millions of years from the remains of ancient plants and sea life.
Question 6
About how much did CO₂ rise from 1960 to 2020?
CO₂ in the air at Mauna Loa, Hawaii (parts per million) - about 100 ppm
- about 400 ppm
- about 50 ppm
- about 10 ppm
Show answer
about 100 ppm
Hint: Subtract the 1960 value from the 2020 value: 414 − 317 = 97, which is about 100.