Atmosphere supports life

As altitude increases, density decreases.
As altitude increases, what happens to the density of the air?
300 miles
Outer space is considered to begin this high above the Earth’s surface.
How much of the Earth’s mass is in the lowest 20 miles?
This gas makes up 78 percent of the atmosphere.
This gas makes up 21 percent of the atmosphere.
the carbon cycle
When we breathe, we inhale oxygen and exhale carbon dioxide. Trees take in the carbon dioxide and release oxygen. What cycle is this an example of?
D. volcanic eruptions
Which of the following causes a sudden change in the atmosphere?
A. global warming
B. the greenhouse effect
C. the nitrogen cycle
D. volcanic eruptions
dust storms
These are powerful windstorms that may raise clouds of eroded soil.
70 percent of the sunlight that reaches the Earth is
infrared radiation
This, from the sun, warms the ground.
Cold air becomes warmer when it contacts the Earth’s surface. This is a process called
Warm air rises, cools, becomes denser, and sinks again. This is a process called
This is the layer of the atmosphere where meteors usually burn up.
This is the layer of the atmosphere that is the highest and the hottest.
This is the layer of the atmosphere that contains all the Earth’s weather.
This is the layer of the atmosphere where the ozone layer is located.
troposphere, mesosphere
These are the layers of the atmosphere where the temperature decreases as you go up.
D. destroys the ozone layer
Which of the following is not a characteristic of ultraviolet radiation?
A.can cause skin cancer B.can harm crops and other materials like paint
C.moves faster than the light we see.
D.destroys the ozone layer
infrared radiation
This type of radiation warms the objects that absorb it.
greenhouse effect.
Gases in the atmosphere absorb and trap infrared radiation. This helps to keep energy in the Earth system for a while. This is called the
B. nitrogen
Which of the following is not a greenhouse gas?
A.carbon dioxide
C.methane D.water vapor
If there were no greenhouse effect, then the average temperature of the Earth would be ________ degrees Fahrenheit.
The combined effect of the greenhouse gases keeps the Earth’s average temperature at ________ degrees Fahrenheit.
D. oxygen
Which of the following gases is not a possible pollutant?

A. ozone
B. carbon monoxide
C. methane
D. oxygen

B. it is in the troposphere.
Ozone gas (O3) is only a pollutant when

A. it is in the stratosphere.
B. it is in the troposphere.
C. it is in the mesosphere.
D. it is in the thermosphere.

burning fossil fuels.
Most air pollution in cities and their suburbs comes from
the Clean Air Act
This limits the amount of pollution that factories, car exhausts, and power plants may give off.
Carbon dioxide stays in the atmosphere for _____________ years.
the Kyoto Protocol
This is an international agreement to lower greenhouse gas emission levels.
the Montreal Protocol
Since 1987, 180 nations have signed this, agreeing to stop production of ozone harming chemicals.