Increases in the Greenhouse Gases
Introduced| English | Meaning |
|---|---|
| Carbon dioxide/ˈkɑːbən daɪˈɒksaɪd/ | The biggest human greenhouse gas. |
| absorbed/əbˈsɔːbd/ | Taken into a material or system rather than being reflected or passing straight through it. |
| Methane/ˈmiːθeɪn/ | The simplest alkane, with molecular formula CH₄. |
| Nitrous oxide/ˈnaɪtrəs ˈɒksaɪd/ | Nitrous oxide |
Why the gases are rising
- The natural greenhouse effect is steady and balanced.
- But human activity is adding extra greenhouse gases fast.
- More gas means more heat trapped, and a warmer planet.
- Different activities release different gases.
Carbon dioxide
- Carbon dioxide 二氧化碳 is the biggest human greenhouse gas.
- Burning fossil fuels for energy and transport releases the most.
- Cutting down forests adds more, releasing stored carbon.
- It also removes trees that would have absorbed 吸收 CO2.
Coal mining and combustion: burning fossil fuels is the main driver of rising atmospheric CO2
The biggest human source of carbon dioxide is…
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Burning fossil fuels for energy and transport is by far the largest human CO2 source.
Methane and nitrous oxide
- Methane 甲烷 comes from cattle, rice paddies, and landfills.
- Per molecule, it traps far more heat than CO2.
- Nitrous oxide 氧化亚氮 comes mainly from fertilizer use.
- These gases are smaller in amount but powerful in effect.
Which greenhouse gas comes from each source?
Match each human activity to the greenhouse gas it mainly releases.
Methane is released in large amounts by…
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Methane comes from cattle, rice paddies, and rotting landfill waste — a powerful greenhouse gas.
Cutting down forests raises CO2 both by releasing carbon and by removing the trees that ____ it.
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Forests absorb CO2; cutting them releases stored carbon and removes a carbon sink — a double hit.
A rising trend
- Since the Industrial Revolution, all these gases have climbed.
- CO2 in the air is now far higher than in all of human history.
- More people and more industry keep pushing the numbers up.
- The rise in greenhouse gases is driving global warming.
Methane traps less heat per molecule than carbon dioxide.
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False. Methane traps far more heat per molecule than CO₂; there is simply much less of it in the air.
Select all human activities that raise greenhouse gases.
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Burning fuels, deforestation, and cattle all raise greenhouse gases. Planting forests lowers CO2.
Not all greenhouse gases are equal. CO2 is the biggest contributor because we release so much of it. But methane traps far more heat per molecule — so even smaller amounts matter a lot. And deforestation is a double hit: it releases carbon and removes the trees that would have absorbed future CO2. Match each gas to its main source, and you know where to cut.
A day's emissions:
- A power plant burns coal, and cars burn petrol — pouring out carbon dioxide.
- On farms, cattle belch methane and fertilizer releases nitrous oxide.
- Meanwhile a forest is cleared, releasing its stored carbon and removing trees that would have absorbed more.
- Every one of these adds to the greenhouse blanket — and each has a different fix.
Human activity is raising greenhouse gases fast. Carbon dioxide (from burning fossil fuels and deforestation) is the biggest. Methane (from cattle, rice, and landfills) traps more heat per molecule. Nitrous oxide comes from fertilizer. Deforestation is a double hit — releasing carbon and removing trees that absorb CO2. The rising trend drives global warming.