The atmosphere and the greenhouse effect Cambridge IGCSE Environmental Management revision
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In plain words
Most of the air you will ever breathe lies within about 15 km of the ground, a distance you could drive in a quarter of an hour if a road went straight up. That thin skin gives us air to breathe, a shield from the Sun, and a blanket that keeps the planet from freezing.
8 things to know
- The atmosphere has four layers. In order from the ground up: the troposphere, the stratosphere, the mesosphere and the thermosphere.
- The troposphere is the lowest layer. It holds most of the air, and weather happens in it.
- The ozone layer is in the lower stratosphere.
- Clean air is 78% nitrogen and 21% oxygen. The remaining 1% includes carbon dioxide, argon and water vapour.
- Climate is the weather conditions in a place, based on the weather over many years.
- The natural greenhouse effect starts with solar radiation passing through the atmosphere. Some is absorbed by the land and oceans, which heats the Earth. Some is reflected back into space.
- Some radiation is absorbed by greenhouse gases and clouds and re-emitted back towards the Earth's surface, so the heat is held in.
- This natural process warms the Earth enough to support life. Without it, the Earth would be far too cold.
Worked example
Explain why the natural greenhouse effect is necessary for life on Earth.
- Radiation from the Sun passes through the atmosphere and warms the land and oceans.
- Greenhouse gases and clouds absorb radiation and re-emit it back towards the surface, instead of letting it all escape to space.
- This keeps the Earth warm enough for liquid water and for living things.
Tips and tricks
- The greenhouse effect is natural and good. The problem is the enhanced greenhouse effect, caused by extra greenhouse gases from human activity.
- To remember the layers from the ground up, take the first letters: T, S, M, T. The ozone layer is in the second one, the stratosphere.
It lands in your notebook with its questions as flashcards.
The atmosphere and the greenhouse effect: 6 questions and answers
These are the quiz’s questions. Do the quiz first, then come back here for the ones that got you.
Which gas makes up most of clean air?
Nitrogen is 78% of the air.
Which layer of the atmosphere is closest to the ground?
Weather happens in the troposphere.
Where is the ozone layer?
The second layer up.
What percentage of clean air is oxygen?
Nitrogen 78%, oxygen 21%.
What does the natural greenhouse effect do?
It is a natural process that life depends on.
Which layer lies directly above the stratosphere?Stretch
The order is troposphere, stratosphere, mesosphere, thermosphere.
Quiz
6 questions
Tap an answer and you’ll see straight away whether it’s right, and why.
Worksheet
3 questions, 7 marks. Write your answers on paper, then check them.
The atmosphere and the greenhouse effect
Cambridge IGCSE Environmental Management 0680 · 7 marks · papermunch.org
Name ______________________________ Date ______________
State the percentages of nitrogen and oxygen in clean air.[2]
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78% nitrogen and 21% oxygen.
Name the four layers of the atmosphere, starting from the Earth's surface.[4]
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Troposphere, stratosphere, mesosphere, thermosphere.
Define the term climate.[1]
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The weather conditions in a location, based on the weather over many years.
Answers: The atmosphere and the greenhouse effect
- 1. 78% nitrogen and 21% oxygen.
- 2. Troposphere, stratosphere, mesosphere, thermosphere.
- 3. The weather conditions in a location, based on the weather over many years.