CK-12 Earth Science for Middle School FlexBook® 2.0
Answer Key
Chapter 12: Climate
12.1 Weather vs. Climate Review Questions 1. What is climate?2. Why did California receive a large influx of new residents? 3. How does climate change?
4. What factors determine climate?
Answers
1. Climate is the long-term average of weather for a region.
2. The new residents were attracted to California’s near-perfect, moderate weather, due to its proximity to the Pacific. The state does not experience the intense cold, snow, and rain of the northeastern and midwestern U.S., where many of the new residents came from.
3. Changes in climate occur very slowly.
4. Climate is determined by many factors, including the angle of the Sun, the likelihood of cloud cover, and air pressure.
Explore More Questions
1. What is the difference between weather and climate? 2. Describe a temperate climate.
3. Where are arid climates found? 4. What creates a climate system? 5. What drives climate?
6. What do greenhouse gases do?
7. What are the main greenhouse gases?
8. What would Earth be like without the greenhouse effect?
1. Weather consists of the elements we see daily such as temperature,
precipitation, and wind. Climate is the average of weather in a region over a longer period of time, often about 30 years.
2. A temperate climate is not especially hot or cold compared with other climates.
3. An arid climate is hot and dry throughout the year.
4. A climate system is created by the interactions between the atmosphere, oceans,
ice sheets, landmasses, and vegetation. 5. The Sun drives climate by heating Earth.
6. Greenhouse gases stop heat from escaping into space. 7. Water, carbon dioxide, methane
8. The planet would be about 30°C cooler and would be uninhabitable for most life we now have.
12.2 Effect of Latitude on Climate Review
Questions
1. How do you explain the variation in temperature from Austin, Texas to Thompson, Manitoba, Canada?
2. What are two reasons that solar radiation is different at different latitudes? 3. Look at the map of temperature versus latitude around the globe. Why are the
bands not straight across?
Answers
1. The variation in temperature is due primarily to the difference in latitude. 2. The Sun’s rays come in less directly the higher the latitude.
3. Other things affects temperature like geography, and air and ocean currents. Explore More
Questions
1. What influences does the Sun have on a region’s climate? 2. Does the tilt of Earth’s axis of rotation influence climate? 3. What is latitude?
4. What is the Equator and what is the climate there like? 5. What is the Tropic of Cancer and the Tropic of Capricorn?
6. What is the climate of the area between the Tropic of Cancer and Tropic of Capricorn?
8. Describe the polar regions.
9. What is elevation? How does elevation affect climate?
10.Besides the amount of precipitation a region gets, what else about precipitation affects climate?
11.How do wind and water currents affect climate?
Answers
1. The Sun has a lot of influence, as it is the source of all light and warmth. Generally, the more sunlight a region gets the warmer it is.
2. The Sun rotates on its axis and revolves around the Sun. The axis of rotation is
tilted so it faces toward and away from the Sun. This causes the seasons so it influences the seasonal climate of a region.
3. Latitude is the distance north or south of the Equator.
4. The Equator is an imaginary line that goes around the widest region of Earth,
right in the middle. The climate at the Equator is sunny and warm all year.
5. The Tropic of Cancer is the latitude line at 23.5 degrees north of the Equator; the Tropic of Cancer is the same but south of the Equator.
6. The climate zone is the tropics and it is warm and wet.
7. The Arctic and Antarctic Circles are at 66.5 degrees north and south of the Equator, respectively. The middle latitudes are between those circles and the circles of the tropics. These are the middle latitudes. These are the temperate zones so not too hot and not too cold.
8. The polar regions are between the Arctic and Antarctic Circles and the poles. They get the least amount of sunlight, receiving no light for half the year. Consequently, they are very cold.
9. Elevation is height above sea level; generally, the higher elevation the colder. 10.Whether the precipitation comes spread throughout the year or in distinct
seasons.
11.Wind and water currents distribute heat and cold around the planet to moderate temperatures.
12.3 Effect of Atmospheric Circulation on Climate Review
Questions
1. What are prevailing winds? How do they affect climate? 2. Where is there not much wind?
3. How do atmospheric circulation cells affect precipitation?
1. Prevailing winds are winds that usually blow. They are an important part of climate because they bring in air and storms from other regions.
2. Where air rises and sinks, at low and high pressure zones.
3. Where air rises, there may be precipitation. Where air sinks there is evaporation; precipitation is rare.
12.4 Effect of Continental Position on Climate Review
Questions
1. Describe a maritime climate. What location has a maritime climate? 2. Describe a continental climate. What location has a continental climate? 3. San Francisco and Virginia Beach are both near an ocean. Why are their
climates so different?
Answers
1. A maritime climate occurs near the coast. It is mild with relatively warm winters and relatively cool summers; precipitation may be high.
2. A continental climate occurs inland. It is more extreme with colder winters and hotter summers.
3. San Francisco has a more maritime climate than Virginia Beach because at that latitude the westerly winds blow marine air over SF but continental air over VB.
12.5 Effect of Altitude and Mountains on Climate Review
Questions
1. Why does an increase in altitude cause a change in temperature? 2. What is rain shadow effect?
3. What are the two ways that a mountain range can affect climate?
Answers
1. An increase in altitude brings a decrease in temperature because with less density the molecules are more spread apart; they have fewer collisions so they generate less heat.
2. Dry air sinks on the leeward side of a mountain range; there is little precipitation so it creates a rain shadow.
3. Temperature decreases with altitude; the leeward side is warmer and drier than the windward side.
Explore More Questions
1. What does wind do as it goes up and over a mountain range? 2. What is the climate on the windward side of a mountain range like? 3. What is the climate on the leeward side of a mountain like?
4. What are rain shadow deserts?
5. What are the characteristics (wind, precipitation, vegetation) seen on the windward side of the Sierra Nevada Mountains?
6. What are the characteristics (wind, precipitation, vegetation) seen on the leeward side of the Sierra Nevada Mountains?
Answers
1. It must go up so it expands and cools. On the other side it contracts and warms.
2. On the windward side, the climate is cooler and wetter.
3. On the leeward side, the climate is warmer and drier.
4. On the leeward side of a mountain range, the air is contracting, which makes it
warmer and drier than on the windward side. It may be so dry that a desert forms, which is called a rain shadow desert.
5. On the windward side, the air rises and becomes cooler. Water vapor condenses and so there is rain and snow. This means that there are forests and lakes. 6. On the leeward side, the air sinks and becomes warmer. There are deserts and
sand dunes. Death Valley is nearby.
12.6 Climate Zones and Biomes Review
Questions
1. What factors determine a climate type? 2. How does a biome relate to a climate zone?
3. Why would a region have its own microclimate, different from the surrounding climate?
4. How are altitude and latitude similar for producing life zones?
1. Temperature, pressure and geography (mountains and oceans)
2. The climate determines the plants that can grow in a region; plant type as well as temperature, precipitation and other climate factors affect what types of animals can live there.
3. The region has different geographic characteristics; it may be in a valley or on top of a mountain.
4. Altitude and latitude track each other in climate characteristics and in the life forms found there.
Explore More Questions
1. What determines the characteristics of the Moab desert? 2. Where are deserts often found?
3. Why are the poles cold?
4. How can the ocean heat the land?
5. How does the mean temperature at Reykjavik, Iceland compare with a similar latitude in Alaska?
6. What brings the warm temperatures to Iceland? 7. How do greenhouse gases affect climate?
8. What are the principal factors in determining climate?
Answers
1. The Moab desert is dry with little precipitation due to its winds and being in a rain shadow.
2. Deserts are frequently on the leeward side of mountain ranges.
3. At the poles, solar radiation comes in at a low angle so they get much less
energy over the year.
4. Ocean currents can bring warm temperatures from tropical regions to colder
areas. When winds blow over this warm water and onto land the land is heated. 5. Reykjavik has a mean annual temperature of about 8 degrees C higher than
Alaska.
6. The Gulf Stream brings Caribbean warmth to Iceland.
7. Greenhouse gases trap the infrared radiation in the atmosphere. The more radiation that is trapped the higher the temperatures will be.
8. The principle factors are precipitation, temperature and human impact. 12.7 Tropical Moist Climates
Questions
1. How does atmospheric circulation lead to there being rainforests in the tropics? 2. How does a tropical wet climate differ from a tropical wet and dry climate? 3. How do the differences in tropical climates lead to differences in vegetation?
Answers
1. Heat at the Equator causes warm air to rise. This warm air cools and condenses leading to rain. The rain feeds rainforests.
2. Tropical wet is right around the Equator; it has high rainfall year round. Tropical wet and dry is at 5 to 20 degrees with a lot of rain in a rainy season but dryness the rest of the year.
3. The constant rain of a tropical wet climate leads to a rainforest; the aridity of the tropical wet and dry leads to grasses rather than trees.
12.8 Dry Climates Review
Questions
1. What is the reason that an arid desert has so little rainfall? 2. What is the reason that a steppe has so little rainfall?
3. What is the difference between a desert and a steppe in vegetation? 4. What adaptations do arid climate zone plants have to the dry conditions?
Answers
1. Atmospheric circulation cells: there is warm descending air at between 15 and 30-degrees north and south of the equator, which leads to deserts.
2. Steppes are usually due to their place in the continental interior or in a rain shadow.
3. Deserts have plants that are adapted to very arid conditions, they are sparse and hardy. Steppes have short grasses and low bushes.
4. Plant adaptations including sun protection.
12.9 Temperate Climates Review
1. At what latitudes do these three climate types occur?
2. What types of plants are found in each of the three climate types above? 3. What is difficult about plants trying to survive in a Mediterranean climate? How
do they do that?
Answers
1. Mediterranean: 30-45-degrees; marine west coast: 45-60-degrees; humid subtropical: 20-40-degrees.
2. Mediterranean: hardy plants like manzanita; marine west coast: dense fir forests; humid subtropical: pine and oak forests
3. Mediterranean climates have arid summers; the plants are short and woody with thick leaves to reduce water loss.
12.10 Continental Climates Review
Questions
1. What is the main feature of a continental climate?
2. What are the temperature and precipitation conditions of the two climates described here?
3. What is the difference in trees in the two climate types described here?
Answers
1. Continental climates do not have any influence from the oceans. They typically have a big difference in conditions between summer and winter.
2. Humid continental have summers that are warm to hot and cold winters with moderate precipitation year round. Subarctic climates have cool, short summers and cold, long winters.
3. Trees in humid continental are deciduous and in subarctic are coniferous.
12.11 Polar Climates Review
Questions
1. What is permafrost? Where do you think it is found?
2. What is tundra? Why is tundra found at the polar regions and in the high mountains?
3. What are ice caps? How does the ice accumulate?
Answers
1. Permafrost is permanently frozen soil that is just beneath the top soil. It is frozen because it is so cold it never gets a chance to melt.
2. Tundra is small ground hugging plants that live in extremely cold environments. Where the climate is not so extreme other types of plants move in, but in the permafrost regions they can’t.
3. Ice caps are thick layers of ice that are present year round. There isn’t much precipitation but when it snows it is typically too cold for the snow to melt.
12.12 Climate Change in Earth History Review
Questions
1. How has climate changed in the past 14,000 years? 2. How can the Sun change Earth’s climate?
3. What is an ice age? When was the most recent?
Answers
1. In the past 14,000 years the trend has been for climate has been to warm but that has not been a linear change.
2. Sunspots may affect climate on Earth by changing the amount of solar radiation; at this time there isn’t a great deal of evidence that they make much difference. 3. An ice age is when temperatures are cooler than normal and glaciers can
advance advance. The last ice age was between 2 million and 14 thousand years ago.
Explore More Questions
1. What were therapsids? What was their great accomplishment? 2. What occurred 250 million years ago?
3. What natural disaster occurred at around the same time?
4. How much warming did Peter Ward calculate could have happened as a result of this natural disaster? What evidence did he use for his calculation?
5. Did this explain the mass extinction at the end of the Permian? Why or why not? 6. What happened during the first phase of the extinction?
7. What happened during the second phase of the extinction? 8. What happened during the third phase of the extinction?
9. What increased between the marine extinction and the final land extinction? What caused this?
10.In all, what caused the Earth’s temperature to rise by 10 degrees?
11.How long did it take for life to recover? What animals came to dominate the Earth?
Answers
1. Therapsids were half mammal and half reptile; the first animals to conquer life on
land.
2. There was a mass extinction in which most organisms went extinct.
3. The Siberian Traps, a massive flood basalt eruption that lasted millions of years;
these eruptions were tens of thousands of times more massive than anything we’ve seen in human history.
4. The Siberian Traps at worst could have brought about 5-degrees of warming. He
calculated this from the volume of basalt and the amount of greenhouse gases it would release.
5. That would be enough to cause some deaths but not the extinctions seen at that time.
6. In the first phase, plants and animals on land started disappearing. This lasted about 40,000 years.
7. In the second phase marine life virtually disappeared.
8. In the third phase, virtually all land plants and animals went extinct also.
9. Carbon-12 was released as well as methane as methane hydrates in the oceans warmed, became unstable and released these greenhouse gases into the
atmosphere.
10.About 4- to 5-degrees was from the Siberian Traps. Another 5-degrees was from global warming from the release of the methane.
11.It took about 100,000 years for life to recover. When it did, the Age of Dinosaurs had begun.
12.13 Short-Term Climate Change Review
Questions
1. In which direction does wind blow during an El Niño event? 2. In which direction does current go during an El Niño event? 3. How is a La Niña different from an El Niño?
Answers
1. West to east
2. West to east
3. In a La Niña winds and currents go east to west, opposite of an El Niño.
4. Warm water piles off of South America. Since this water is buoyant, cold water can’t upwell from deep. This means the nutrients can’t rise and so small
organisms have no food source. They die and then larger organisms die. 12.14 Carbon Cycle and Climate
Review Questions
1. What does it mean to say that photosynthesis and respiration are gas exchange processes?
2. How do scientists learn about carbon levels in the past? 3. How do human activities affect the carbon cycle?
Answers
1. Photosynthesis uses carbon dioxide in the environment to create oxygen and
carbon.
2. One method is by measuring composition of air bubbles in glaciers.
3. Humans using coal, oil, and gases have added more carbon dioxide to the atmosphere, accelerating the greenhouse effect. Deforestation has also
destroyed the trees that would naturally be able to take carbon dioxide out of the atmosphere.
Explore More Questions
1. What do greenhouse gases do?
2. Where did most of the carbon dioxide that was present in the early atmosphere go?
3. What did the early plants add to the atmosphere and why was that important? What else did they create?
4. What do organisms do with the organic carbon? 5. What are the two major things that carbon does? 6. What is the 30 second version of the carbon cycle? 7. What does carbon fixation do with carbon dioxide?
8. How do organisms use the carbohydrates produced by carbon fixing reactions? 9. What is cellular respiration the reverse of?
10.After the organisms metabolize carbohydrates, how is the carbon released back into the environment?
11.What happens when carbon dioxide mixes with water and what does it cause? 12.What happens to the carbonate ions in the marine environment?
13.What happens when shell building organisms die? What happens if those organisms are buried deeply?
14.How much carbon is wrapped up in fossil fuels compared to the total amount of carbon?
15.Where does the carbon dioxide go that is released from fossil fuels? Where does the excess carbon dioxide go?
Answers
1. Greenhouse gases absorb heat energy.
2. In the early atmosphere, plants used up most of the carbon dioxide.
3. Plants produce oxygen and used up carbon dioxide, allowing heat to escape
back into space, and creating a carbon that can be used by other living things.
4. Organisms get their energy from organic carbon.
5. Carbon is the route of energy transfer between organisms, and traps heat in the
atmosphere
6. Plants use the carbon from carbon dioxide in the atmosphere to create food for
herbivorous animals. The carbon returns to the environment in several different ways, bringing it back into the air, water, or soil. It can then be extracted back into the atmosphere either naturally or used by humans, starting the cycle over again.
7. Carbon fixation is the process of turning atmospheric carbon into organic
compounds such as sugar.
8. They can use carbohydrates for energy or for building material.
9. Carbon fixation
10.By exhaling
11.Carbon dioxide in water makes the water more acidic
12.These ions will get stuck to rocks, weathering them, or will be used by marine
invertebrates to form their shells and skeletons
13.Carbonate ions are released back into the environment, or if they are buried, will
eventually pile up and make rocks like limestone. 14.0.006% of carbon on Earth is in fossil fuels
15.It is released back into the environment to rejoin the carbon cycle, but plants can only process a small amount of this. The rest gets trapped in the atmosphere, accelerating the greenhouse effect, causing temperatures to rise.
Review Questions
1. What have been the temperature trends in the past 1500 years?
2. How is the rise in temperatures in the past two decades different from the rise since of the past 1500 years?
3. What is global warming?
Answers
1. Temperatures have been up and down but the general trend has been up.
2. In the past two decades temperatures have been up dramatically. 3. The rise in average global temperatures.
Explore More Questions
1. How much has the global temperature risen in the last century?
2. What is the major human activity that contributes to global warming and why? 3. What is the greenhouse effect?
4. Is average global temperature rising? What is your evidence?
5. Which greenhouse gases are at their highest levels in history? When was the last time they were as high?
6. What do researchers predict will happen?
7. What can we do now to slow the rise in temperatures?
Answers
1. 1.2-1.4°F
2. Burning fossil fuels such as oils and gases contributes to global warming.
3. Energy from the sun that normally would radiate back into space get trapped in
the environment by greenhouse gases, warming it like a greenhouse.
4. A string of abnormally warm years point to evidence of global warming by the
greenhouse effect.
5. Carbon dioxide and methane are at their highest in the last 400,000 years.
6. Arctic sea ice will decline, and the global temperatures will rise 2-10°F over the next century.
7. Driving less, saving electricity, and switching to fluorescent light bulbs 12.16 Causes and Effects of Global Warming
Questions
1. What do you expect to happen if you increase the amount of greenhouse gases in the atmosphere?
2. What has happened to the level of carbon dioxide in the atmosphere in the past several decades (use numbers and units)?
3. What has happened to sea level since 1870 (use numbers and units)?
4. What are some of the effects of climate change that are already being seen?
Answers
1. If the amount of greenhouse gases increases, more heat will be trapped in the atmosphere.
2. Atmospheric carbon dioxide has increased by more than 80 parts per million. 3. Sea level has risen nearly 9 inches.
4. Besides rises in sea level, there have been a decrease in summer sea ice in the Arctic; an increase in severe storms, floods, and droughts; and effects on
seasonality of animals.
12.17 Impact of Continued Global Warming Review
Questions
1. Pretend that the temperature today is 5° C (9° F) higher than yesterday. Now consider an increase of 5° C (9° F) in average global temperature. How are these two scenarios different?
2. Why is a rise in sea level significant?
3. What will plants and animals do as temperature rises?
Answers
1. How you feel about a 5°C (9°F) rise in temperature depends on yesterday’s weather. If it was cold, the temperature increase might feel very good. However, if it was very hot, the rise might be unwelcome. A rise of 5°C (9°F) in average global temperature has more dramatic and long-term consequences. Throughout the year, there will be many more very hot days and record-breaking
temperatures. Winters in general will no longer be nearly as cold.
2. A lot of major cities are located along coasts. There are many regions, like the country of Bangladesh, where millions of people live in low-lying areas that will flood if the sea level rises. For these places, an increase in sea level will result in numerous deaths and create climate refugees.
3. As the temperature rises, plants and animals will be forced to move uphill or toward the polar regions, or otherwise die out.
Explore More Questions
1. Climate has always been changing. Why is it something to worry about now? 2. Describe the changes that could be seen if the Earth warms by one degree. 3. Describe the effects of two degrees of warming.
4. What changes will occur with three degrees of warming? 5. Describe the consequences of four degrees of warming.
Answers
1. The pace of climate change today is unprecedented.
2. The Arctic would be ice-free for half the year; tens of thousands of homes around the Bay of Bengal would be flooded; more hurricanes would hit the South
Atlantic; severe droughts would cause global grain and meat shortages; the western United States would turn into desert.
3. Greenland’s glaciers would disappear; polar bears would struggle for survival; insects would be forced to migrate; pine beetles would advance north and kill off white-barked forests, disrupting ecosystems; permafrost would melt, allowing forests to expand northward; some Pacific Islands would be submerged; coral reefs would be devastated.
4. The Arctic would be ice-free all summer; the Amazon rainforest would dry out; snow caps in the Alps would melt; El Niño’s extreme weather patterns would become normal; the Mediterranean and parts of Europe would experience brutally hot, even fatal summers.
5. The oceans would rise, flooding the homes of one billion people; Bangladesh, Egypt, and Venice, Italy would be submerged; glaciers would disappear, shutting off a source of fresh water to billions of people; northern Canada would become a big agricultural zone; the West Antarctic ice sheet would be on the verge of collapsing; crucial rivers would run dry.
12.18 Reducing Greenhouse Gas Pollution Review
Questions
1. Why is a treaty between nations needed so that we can reduce greenhouse gas emissions? Why is there a problem getting a treaty that will work?
2. How does a cap-and-trade system work? Could it work for cities or businesses in the same way it does for nations?
3. What is carbon sequestration? Does it prevent carbon dioxide from being emitted? Does it keep carbon dioxide from entering the atmosphere?
Answers
1. Nothing much happens without a treaty. The climate change issue has become extremely political.
2. Each nation gets an allotment of carbon to release annually; if they think they are going over, they can buy or trade for another nation’s rights. It could work on a smaller scale.
3. Carbon sequestration removes carbon and stores it. The gases are captured at the power plant before they enter the atmosphere.
Explore More Questions
1. What is the purpose of carbon sequestration?
2. What are the three pillars of the Global Climate Change Initiative? 3. What is CCS?
4. What is CCS being used for today? 5. How is CCS done?
6. What type of stone is carbon dioxide pumped into? Why?
7. Why are cap rocks important? How do scientists know cap rocks work?
Answers
1. To reduce greenhouse gas emissions into the atmosphere.
2. Increase energy efficiency, increase renewable energy sources and use carbon sequestration.
3. Energy efficiency and renewable energy can’t reduce carbon dioxide enough to we also need to store carbon.
4. CCS is a broad group of technologies to capture and store carbon.
5. Carbon dioxide is injected into old oil wells to increase the amount of oil that comes out.
6. Gases are captured at the power plant and injected into a storage rock. 7. Sandstone is a good storage rock because it is porous; it has holes for the
carbon to fill.
8. Cap rocks are impermeable so the carbon can’t rise to the surface. Oil and gas is stored beneath cap rocks for millions of years.
