CHAPTER 10

In a runaway greenhouse effect, more water begins to evaporate from the oceans, which in turn ________. 1. means less water available to cause rainfall, causing a planet to become more desert-like 2. exposes deeper waters to the atmosphere, so that they can evaporate too 3. increases the strength of the greenhouse effect, causing even more warming 4. causes more carbon dioxide to be outgassed from volcanoes, increasing the greenhouse effect

3. increases the strength of the greenhouse effect, causing even more warming

The current concentration of carbon dioxide in Earth's atmosphere is ________. 1. higher than it has ever been in Earth's history 2. higher than it has been during the past century, but lower than at many other times during past millennia 3. significantly higher than it has been for at least several hundred thousand years 4. rising, but still about average for the past few hundred thousand years

3. significantly higher than it has been for at least several hundred thousand years

The habitable zone refers to ________. 1. the regions around a star in which Earth-size planets exist 2. the regions on a planet where life could potentially exist 3. the range of distances from a star within which a planet could potentially have surface oceans of liquid water 4. the range of distances from a star at which a planet or moon could potentially have surface or subsurface oceans of liquid water Submit

3. the range of distances from a star within which a planet could potentially have surface oceans of liquid water

Earth has been gradually warming over the past few decades. Based on a great deal of evidence, scientists conclude that this warming is caused by _____. 1. the human release of chemicals called CFCs into the stratosphere 2. the increase in forest fires during recent years 3. the fact that our politicians spout a lot of hot aira small 4. increase in the amount of energy coming from the Sun 5.. human activities that are increasing the concentration of greenhouse gases in Earth's atmosphere

5.. human activities that are increasing the concentration of greenhouse gases in Earth's atmosphere

Is Venus in the habitable zone?

no

the presence or absence of a significant atmosphere sometimes depends on

the size

What will happen to the Sun's habitable zone in the future? 1. It will move outward. 2. It will move inward. 3. It will become much wider. 4. It will become much narrower.

1. It will move outward.

Scientifically speaking, which of the following ideas relevant to global warming is subject to the greatest uncertainty? 1. Predictions of future consequences of global warming 2. The idea that more atmospheric carbon dioxide should cause Earth to get warmer 3. The idea that Earth has been warming over the past century 4. The idea that human activity is increasing the atmospheric carbon dioxide concentration Submit

1. Predictions of future consequences of global warming

What factors influence surface habitability

1. The role of distance from a central star 2. the role of planetary size 3. the role of an atmosphere

Key evidence that Venus once had much more water than it does today comes from ________. 1. Venus's relatively high ratio of deuterium to ordinary hydrogen atoms 2. measurements of the amount of sulfuric acid in Venus's clouds 3. surface features that appear to be former ocean basins 4. studies of the composition of outgassing by volcanoes on Venus

1. Venus's relatively high ratio of deuterium to ordinary hydrogen atoms

Global warming refers to ________. 1. an increase in Earth's average surface temperature 2. the warming that will occur on Earth as the Sun brightens in the future 3. the idea that every place on Earth is getting warmer 4. any warming caused by human activity

1. an increase in Earth's average surface temperature

Based on all current evidence, if Venus had been born at Earth's distance from the Sun, then Venus today would probably ________. 1. have oceans and an atmosphere much like Earth 2. be similar in temperature to Earth but would lack plate tectonics and a carbon dioxide cycle 3. still have suffered a runaway greenhouse effect because it has so much carbon dioxide 4. have seas of liquid carbon dioxide

1. have oceans and an atmosphere much like Earth

what are two ways in which a planet can lose its atmosphere

1. large impaces in principle blast significant amounts of atmospheric gas into space. 2. solar wind

If Earth were moved to Venus's orbit, it would probably ________. 1. suffer a runaway greenhouse effect and become hotter than Venus 2. warm up enough to evaporate the oceans, but it would not approach the temperature of Venus 3. stay about the same temperature, thanks to the relatively small amount of carbon dioxide in our atmosphere 4. become about 30°C warmer, making our planet more tropical

1. suffer a runaway greenhouse effect and become hotter than Venus

The reason that some scientists think that Venus might have had oceans early in its history is that _________. 1. the Sun was probably dimmer at that time 2. Venus's surface shows evidence of continents and ocean basins 3. Venus probably was born farther from the Sun and migrated to its current orbit 4. old regions of Venus's surface show impact craters that appear eroded by rainfall

1. the Sun was probably dimmer at that time

what are two evidences that Venus had ongoing volcanic activity

1. venus's clouds contains sulfuric acid which is made from sulfur dioxide and water 2. found rocks on three volcanoes

Venus probably once had as much water (or water vapor) as Earth. What do we think happened to all this water? 1. It is hidden in subsurface reservoirs. 2. The water molecules were destroyed, and the hydrogen atoms escaped to space. 3. It exists as water vapor in Venus's clouds. 4. It became locked into rocks as hydrated minerals.

2. The water molecules were destroyed, and the hydrogen atoms escaped to space.

Is Europa in the Sun's habitable zone? 1. It is if it really has a subsurface ocean, but otherwise is not. 2. Yes 3. No

3. No

Suppose that Greenland's ice sheet was to melt completely. What effect would that have on sea level? 1. Sea level would rise enough to put all but the tallest mountains underwater. 2. No effect on sea level, but the ocean would be colder. 3. Sea level would rise many meters. 4. Sea level would rise about 1 meter. 5. Sea level would rise about 3 meters.

3. Sea level would rise many meters.

Venus's atmosphere has much more carbon dioxide than Earth's because ________. 1. volcanoes on Venus must have outgassed much more carbon dioxide than those on Earth 2. Venus was born in a region of the solar system where carbon dioxide could condense 3. Venus lacks oceans 4. Venus was born in a region of the solar system that had more carbon dioxide

3. Venus lacks oceans

Overall, the requirements for a planet to have a habitable surface seem to be ________. 1. only an orbit within the habitable zone 2. only a size large enough to retain substantial internal heat 3. both an orbit within the habitable zone and a size large enough to retain substantial internal heat

3. both an orbit within the habitable zone and a size large enough to retain substantial internal heat

Which of the following is not an expected consequence of global warming? 1. An increase in the number and intensity of hurricanes. 2. An increase in the severity of winter blizzards. 3. Melting of polar ice and glaciers. 4. The entire Earth will warm up by the same amount.

4. The entire Earth will warm up by the same amount.

The inner boundary of the Sun's habitable zone today is ________. 1. slightly inside the orbit of Venus 2. at 98% of Earth's distance from the Sun 3. slightly beyond the orbit of Earth 4. between the orbit of Venus and the orbit of Earth Submit

4. between the orbit of Venus and the orbit of Earth Submit

A carbon dioxide concentration of 400 parts per million (ppm) means that carbon dioxide represents ________ of Earth's atmosphere. 1. about 0.4% 2. about 40% 3. about 4% 4. less than 0.1%

4. less than 0.1%

Based on current evidence, if Mars had been born at Earth's distance from the Sun, then Mars today would probably ________. 1. have oceans and an atmosphere much like Earth 2. have much more volcanic activity and outgassing 3. have suffered a runaway greenhouse effect 4. still have a dry surface

4. still have a dry surface

In terms of the gases outgassed by volcanoes, Venus's atmosphere today seems to have ________. 1. too much carbon dioxide 2. too much carbon dioxide and too little water vapor 3. too little carbon dioxide 4. too little water vapor

4. too little water vapor

moist greenhouse effect

A process by which a planet could lose water when the atmospheric circulation allows water vapor to rise high enough to be broken apart by ultraviolet light from the Sun.

How to prove that Venus lost a significant amount of water

Evidence comes from the isotope of hydrogen called Deuterium. It is twice as heavy as ordinary hydrogen atom and therefore cannot escape to space as easily and we can count the leftover Deuterium atoms, but it is only a lower limit

Venus's upper atmosphere is vlunerable to solar wind because

Venus lacks a protective magnetic field because of its slow rotation

why does venus not have a carbon dioxide cycle

because it has no liquid water in which the gas can dissolve into and thus all of its Co2 is in its atsmophere because it has no oceans

What is the immediate cause of Venus's high temperature

extreme greenhouse effect produced primarily by atmospheric carbon dioxide

true or false: simply being in a star's habitable zone is sufficient to make a world habitable

false

where is the only place where Venus can possible have water

it its atmosphere

Why didn't Earth lose water in the same way

on earth, most of the outgassed water vapor condensed into rain, forming oceans long before UV radiation could break it apart because the UV light is absorbed by the ozone layer

in its final death throes, the sun will expel its outer layers into space, creating a

planetary nebula

what is the leading hypothesis for the disappearance of VEnus's water

similar to mars, UV light from the sun broke apart water molecules in VEnus's atmosphere and the H atoms then escaped to space

runaway greenhouse effect

the increase in temperature would lead to an increase evaporation of water from the oceans and ti would also allow the atmosphere to hold more water vapor before the vapor condensed to make rain. The combination of more evaporation and greater atmospheric capactiy for water vapor would substantially increase the total amount of water vapor in Earth's atmosphere and would therefore strengthen the greenhouse effect.

Where are the boundaries of the sun's habitable zone today

the inner boundary makes the place where, if a planet were any closer to the sun, a runaway greenhouse effect would be triggered. the outer boundary marks the place where, if a planet were any farther from the sun, surface water would freeze

Definition of Habitable Zone

the region around a star in which planets could potentially have surface temperatures at which liquid water could exist

Why did Venus keep its atmospheric Carbon dioxide and earth did not

they have similar amounts of CO2, its just that on Earth it is all locked up in carbonate rocks or dissolved in the oceans through the carbon dioxide cycle.

true or false: habitable zones occur with time

true

true or false; regardless of how far Mars is from the sun, if Mars were larger and retained a thick atmosphere, it might still have enough greenhouse warming to have a habitable zone

true

all that will remain of the sun will be its hot central core called a

white dwarf star

what would happen if we move Earth to Venus's distance from the sun

would have a runaway greenhouse effect