Lesson · Grade 7 · Science
How people are changing the climate
- Grade 7
- Science
- 1 min 14 s
- British Columbia
- BC7-SC-41
A three-box chain diagram builds up left to right: what people do (burning coal, oil and gas; cutting down forests), what that does to the air (carbon dioxide molecules gathering, with bars showing about 280 parts per million 200 years ago against over 420 now), and what happens to Earth (heat trapped by the gas, a thermometer rising to over 1 °C warmer than the 1800s, the polar ice shrinking, and a list of impacts). It opens with Earth alone and the contrast between slow past changes and today's fast change, and ends on the one-line recap that people add carbon dioxide, it traps heat, and Earth warms.
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In one sentence
The question this lesson answers
How are people changing Earth's climate?
Earth's climate has changed before, but slowly, over thousands of years.
Transcript
What the lesson says
How are people changing Earth's climate?
Earth's climate has changed before, but slowly, over thousands of years.
Today it is changing much faster, and people are the main reason.
For about 200 years, people have burned coal, oil and gas for energy.
Burning these fuels gives off carbon dioxide, a greenhouse gas.
Trees take carbon dioxide out of the air.
Cutting down forests means less of it is taken back out.
Two hundred years ago, the air held about 280 parts per million of carbon dioxide.
Now it holds over 420 parts per million, about half as much again.
Carbon dioxide traps heat that would have escaped to space.
Earth is now more than 1 degree Celsius warmer than in the late 1800s.
Ice is melting, and sea levels are rising.
Heat waves and heavy rain are becoming more common.
People add carbon dioxide to the air, it traps more heat, and Earth warms up.
Curriculum
Where this fits
- British Columbia, Grade 7
Science, Earth science: evidence of climate change over geological time and the recent impacts of humansBC7-SC-41
Previous: Reading Past Climate: Ice Cores, Tree Rings and FossilsNext: Climate Change and Living Things: Move, Change, or Die Out
The outcomes and strands follow the British Columbia curriculum.
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