exam 3 part 3
Using only pencil and paper calculations, Arrhenius concluded that a doubling of the carbon dioxide concentration would raise global temperatures by about
5° C
Imagine that you visit an alien world that has an atmospheric composition similar to that of Earth (that is, mostly nitrogen and oxygen) and a surface atmospheric pressure of 1.2 bars. Which of the following statements best describes the effects of this pressure?
It will feel quite similar to the atmospheric pressure on Earth.
Why is Mars red?
Its surface rocks were rusted by oxygen.
What are greenhouse gases?
gases that absorb infrared light
Which process is the primary source of the atmospheric gases on Earth?
outgassing from volcanoes
Which of the following is not a product of outgassing?
oxygen
Which of the following gases absorbs ultraviolet light best?
ozone
What causes the release of oxygen into Earth's atmosphere?
photosynthesis
From where did the molecular oxygen in Earth's atmosphere originate?
photosynthesis from single-celled organisms
What kind of light warms the stratosphere?
ultraviolet
Suppose Earth's atmosphere had no greenhouse gases. Then Earth's average surface temperature would be
250 K, which is well below freezing.
Greenhouse gases in the atmosphere, such as carbon dioxide and water vapor, make Earth warmer than it would be otherwise because these gases __________.
absorb infrared light emitted by the surface
The thermosphere is warm because it
absorbs X rays.
Scientists have confidence in the predictions of today's best climate models because they __________.
agree well with actual data for recent decades
X rays from the Sun's corona
are absorbed in Earth's thermosphere.
Where is most of the water on Mars?
in its polar caps and subsurface ground ice
The greenhouse effect raises Earth's surface temperature (from what it would be otherwise) because the infrared light radiated by Earth's surface __________.
is absorbed by greenhouse gases, slowing the escape of this energy to space
What kind of gas is most affected by thermal escape?
light gases
Where is most of the CO2 that has outgassed from Earth's volcanoes?
locked up in rocks
Convection occurs in the troposphere but not in the stratosphere because
lower altitudes of the troposphere are warmer than higher altitudes, unlike in the stratosphere.
The sky is blue because
molecules scatter blue light more effectively than red light.
The greenhouse effect occurs in the
troposphere.
Earth outgassed as much carbon dioxide as Venus, but it is locked up in the oceans and rocks.
true
One bar of atmosphere is roughly equal to Earth's atmospheric pressure at sea level
true
All the following statements are true. Which two represent the two facts that lead us to expect Earth to be warming up as a result of human activity? Be sure to choose two of the statements below.
-Human activity is increasing the concentration of carbon dioxide and other greenhouse gases in the atmosphere. -Greenhouse gases make Earth warmer than it would be otherwise.
Which of the following statements about the greenhouse effect is true?
-Without the naturally occurring greenhouse effect, Earth would be too cold to have liquid oceans -One result of an increased greenhouse effect on Earth may be an increased number of severe storms. -A weak greenhouse effect operates on Mars -The burning of fossil fuels increases the greenhouse effect on Earth because of the release of carbon dioxide. -All of the above are true
Which of the following occur as the greenhouse gas concentration increase?
-more infrared light is absorbed in the lower atmosphere -the average surface temperature rises
Earth's temperature remains fairly steady, which means that Earth must return nearly the same amount of energy to space that it receives from the Sun. In what form(s) does Earth return most of this energy to space?
-visible light reflected by clouds -visible light reflected by the surface -infrared light emitted by the surface and atmosphere
Earth's stratosphere is heated primarily by which process?
Absorption of ultraviolet radiation by ozone.
Since the time Arrhenius made his prediction, the carbon dioxide concentration has risen by about 30% and the global average temperature has risen by about 1°C. Which statement below best describes how scientists should evaluate Arrhenius's prediction?
Although Arrhenius's prediction was not exact, the actual change is similar enough to the predicted change to validate the general idea that a rising carbon dioxide concentration would lead to global warming.
Which of the following is not an expected consequence of the rising carbon dioxide concentration or global warming?
Animal deaths due to carbon dioxide poisoning.
Why does the burning of fossil fuels increase the greenhouse effect on Earth?
Burning releases carbon dioxide into the atmosphere.
Of the four gases CO2, H2O, N2, and O2, which are greenhouse gases?
CO2 and H2O
As you found in Part A, early Mars had both core convection and a strong magnetosphere. What is the connection between these two things?
Core convection helps generate a magnetic field, and the magnetic field creates the magnetosphere.
Each of the following statements was either true for Mars in the distant past (early Mars) or is true for Mars today. Sort the statements by dragging each into the correct bin.
Early Mars (more than 3 billion years ago) -Some craters held lakes of water. -Strong greenhouse effect. Substantial volcanism and outgassing. -Strong magnetosphere. -Core convection. Mars Today -Very weak greenhouse effect. -Surface pressure too low for stable liquid water. -Solar wind strips atmospheric gas.
Arrhenius was not particularly alarmed by his discovery at the time. What changed that made later scientists become much more concerned about the climate effects of carbon dioxide?
Emissions of carbon dioxide rose much faster than Arrhenius had anticipated.
The Moon has no detectable atmosphere.
False
How is the atmosphere of a planet affected by the rotation rate?
Faster rotation rates produce stronger winds.
How does the greenhouse effect work?
Greenhouse gases transmit visible light, allowing it to heat the surface, but then absorb infrared light from Earth, trapping the heat near the surface.
What motivated Arrhenius to calculate how changes in carbon dioxide might affect the climate?
He was seeking to understand the causes of ice ages.
What key process underlies why Mars changed so much from its early conditions to its conditions today?
Interior cooling.
Why does Venus have such a great difference in temperature between its "no atmosphere" temperature and its actual temperature?
It has a large amount of greenhouse gases in its atmosphere
As discussed in the video, the leading hypothesis for why Mars changed holds that interior cooling led to loss of its magnetosphere, allowing the solar wind to strip atmospheric gas away. How has the MAVEN mission provided evidence for this hypothesis?
It has measured rates of gas loss from the atmosphere today.
Which of the following best describes rain on Venus?
It has sulfuric acid rain in its atmosphere, but the drops evaporate before hitting the surface.
What happens to the energy that the ground absorbs in the form of visible sunlight?
It is returned upward in the form of infrared light
Why doesn't Mars have a stratosphere?
It lacks a layer of ultraviolet absorbing gas.
Deuterium is more abundant on Venus than elsewhere in the solar system. What do we think this fact tells us about Venus?
It once had huge amounts of water in its atmosphere.
On a cloudless day, what happens to most of the visible light headed toward Earth?
It reaches Earth's surface, where some is reflected and some is absorbed.
What is the leading hypothesis for Venus's lack of water?
Its water molecules were broken apart, and hydrogen was lost to space.
All of the following statements are true. Which one explains why Mars has lost so much more interior heat than Earth.
Mars is smaller than Earth.
Which of the following planets has the least substantial atmosphere?
Mercury
Which planet experiences the greatest change between its actual day temperature and actual night temperature?
Mercury
When were the heat-trapping effects of gases that cause the greenhouse effect first measured by scientists?
More than 150 years ago.
Venus may have started with an ocean's worth of water. Where is its water now?
The water was lost when ultraviolet light broke apart water molecules and the hydrogen escaped to space.
According to scientists, the naturally occurring greenhouse effect makes Earth about 31∘C warmer than it would be if there were no greenhouse gases in our atmosphere. How do scientists "know" what Earth's temperature would be without greenhouse gases?
They calculate this temperature from Earth's reflectivity and distance from the Sun.
Venus has a thicker atmosphere than Earth.
True
Which of the following worlds has the greatest difference in temperature between its "no atmosphere" temperature and its actual temperature?
Venus
Which of the following worlds has the most substantial atmosphere?
Venus
Which terrestrial world has the most atmosphere?
Venus
Which planet(s) have an atmosphere that consists mostly of carbon dioxide?
Venus and Mars
The following images show the four terrestrial planets in our solar system (not to scale). Rank these planets from left to right based on the total amount of gas in their atmospheres, from most to least.
Venus earth, mars, mercury
All of the following statements are true. Which one provides strong observational support for the claim that greenhouse gases make a planet warmer than it would be otherwise?
Venus has a higher average temperature than Mercury.
Which of the following correctly lists the terrestrial worlds in order from the thickest atmosphere to the thinnest atmosphere? (Note: Mercury and the Moon are considered together in this question.)
Venus, Earth, Mars, Moon/Mercury
Geological evidence points to a history of extended ice ages in Earth's history. How did Earth recover from this snowball phase?
Volcanoes continued to inject CO2 into Earth's atmosphere, increasing the greenhouse effect to the point where ice melted.
Based solely on an understanding of the greenhouse effect (as displayed in the figure), which one of the following statements is true?
We should expect an increase in the greenhouse gas concentration to lead to global warming.
What is the difference in meaning between the terms weather and climate?
Weather refers to short-term variations in conditions, and climate refers to long-term variations in conditions.
Which of the following is the most basic definition of a greenhouse gas?
a gas that absorbs infrared light
The strength of the Coriolis effect depends on
a planet's size and rotation rate.
The atmosphere on Mercury is due to
bombardment.
In which direction do hurricanes in the Southern Hemisphere rotate?
clockwise
Which of the following planets has a stratosphere?
earth
There are no aurora on Venus because it
lacks a strong magnetic field
Ultraviolet light is absorbed in the
stratosphere.
Sunsets are red because
sunlight must pass through more atmosphere then, and the atmosphere scatters even more light at bluer wavelengths, transmitting mostly red light.
Which region of Earth has warmed the most in recent decades?
the Arctic
What are fossil fuels?
the carbon-rich remains of plants that died millions of years ago
What is the exosphere?
the highest layer in the atmosphere
What is the troposphere?
the lowest layer in the atmosphere
What is the thermosphere?
the part of the atmosphere that absorbs X rays
What is the stratosphere?
the part of the atmosphere that absorbs ultraviolet
The proper order of the layers of a generic atmosphere from lowest altitude to highest is
troposphere, stratosphere, thermosphere, exosphere
Drag the layers into place in the correct order from lowest altitude at left to highest altitude at right.
troposphere,stratosphere,thermosphere, exosphere
Which terrestrial planet would have its surface temperature the most dramatically changed if its greenhouse gases were removed from its atmosphere?
venus
The following images show the four terrestrial planets in our solar system (not to scale). Rank these planets from left to right based on the atmospheric pressure at the surface, from highest to lowest.
venus, earth, mars, mercury
The energy that warms Earth's surface comes primarily in the form of __________.
visible light from the Sun
The ionosphere is a layer of ionized gas that is
within the thermosphere
