Earth's Climate: Past and Future Final
800,000-year-old glacial ice has been recovered from the Antarctic ice sheet. True or False?
True
Benthic foraminifera are ocean bottom-dwelling organisms that form shells of CaCO3. True or False?
True
Changes in the height of bedrock can persist for thousands of years after ice sheets disappear. True or False?
True
Deep ocean waters tend to be colder and saltier than waters at the surface. True or False?
True
Deep-water formation in the North Atlantic was relatively slower and shallower during Heinrich events. True or False?
True
Evidence from the Newark Basin suggests that the strength of the Pangaean monsoons was controlled by orbital precession modulated by eccentricity. True or False?
True
Ferns and trees disappeared from Antarctica after 40 million years ago in response to cooling climate and the spread of ice. True or False?
True
If the Earth's axis was not tilted with respect to the plane of orbit, the length of every day would be the same everywhere. True or False?
True
Prior to 1900, the source of most of the additional carbon added to the atmosphere by human activities was forest clearance. True or False?
True
Sea ice along the coasts of Iceland and Greenland was less frequent between 1000 and 1300 than it was in subsequent centuries. True or False?
True
Shells of foraminifera become more enriched in 18O when climate cools. True or False?
True
The last several glacial/interglacial cycles show a characteristic long period of ice volume increase followed by a short period of rapid ice melting. True or False?
True
The latitudinal temperature gradient during the Cretaceous was smaller than it is today. True or False?
True
The radiant energy important to Earth's climate system falls within a narrow band of the electromagnetic spectrum from infrared to ultraviolet. True or False?
True
For about what fraction of Earth's history have our species Homo sapiens been present? A. 1/10 of Earth's age B. 1/10,000 of Earth's age C. 1/100 of Earth's age D. 1/100,000 of Earth's age E. 1/1000 of Earth's age
**B. 1/10,000 of Earth's age
Which of the following constitutes evidence supporting the hypothesis that the ice sheets experienced more basal sliding early in the period of northern hemisphere glaciation than they did later? A. Ancient soils and sedimentary rocks were the main type of debris eroded prior to the last 1.5 to 1 million years, while freshly pulverized debris of hard rock has predominated since that time. B. Models show that ice sheets before 1.5 million years ago were thicker and frozen to their base. C. The presence of deep soils and sedimentary rock cover over much of north-central Canada today. D. All of the answers are correct. E. None of the answers is correct.
A. Ancient soils and sedimentary rocks were the main type of debris eroded prior to the last 1.5 to 1 million years, while freshly pulverized debris of hard rock has predominated since that time.
What is one direct result of the circulation of molten iron in Earth's core? A. Earth's magnetic field B. subduction of ocean crust C. the movement of lithospheric plates D. volcanoes on Earth's surface E. All of the answers are correct.
A. Earth's magnetic field
Examine the following figure showing global averages of temperature based on surface station thermometers and determine which of the following is correct. A. Global average temperatures warmed by 0.8°C in the last 110 years. B. The last year that global average temperatures dropped was 1975. C. Global average temperatures were significantly colder in 1900 than in 1950. D. All of the answers are correct. E. Both A and B are correct.
A. Global average temperatures warmed by 0.8°C in the last 110 years.
What effect did the eruption of Mount Pinatubo in 1991 have on global climate? A. It cooled global climate by ~0.3°C for the year after the eruption. B. It cooled global climate by ~0.6°C for the three years after the eruption. C. It warmed global climate by ~0.1°C to 0.2°C for the month after the eruption. D. Both A and C are correct. E. All of the answers are correct.
A. It cooled global climate by ~0.3°C for the year after the eruption.
How does a CO2 feedback potentially explain the mismatch between the strengths of the 41,000-year insolation and ice sheet power spectra between 2.75 and 0.9 Myr? A. It could amplify the ice volume response to insolation forcing at the 41,000-year cycle. B. It could amplify the ice volume response to insolation forcing at the 23,000-year cycle. C. It could diminish the ice volume response to insolation forcing at the 41,000-year cycle. D. It could diminish the ice volume response to insolation forcing at the 23,000-year cycle. E. All of the answers are correct.
A. It could amplify the ice volume response to insolation forcing at the 41,000-year cycle.
Examine the following figure showing data from the Hudson Bay region and determine which of the following statements is correct. A. Land that was once beneath the ice sheet has been rising for thousands of years. B. The rate of beach elevation change is decreasing rapidly. C. The beach elevation change results from a sea level drop. D. All of the answers are correct. E. Both A and B are correct.
A. Land that was once beneath the ice sheet has been rising for thousands of years.
What is the basic premise of the variability selection hypothesis? A. Rapid evolution occurred because habitat alteration put new demands on our ancestors, and those ancestors with traits best adapted to these new conditions were the ones to survive. B. The variables that are used in GCM simulations should be selected with a direct purpose and not randomly. C. Geographic variability in climatic zones affected early hominids in the north more than those in the tropics. D. Hominids with the largest braincases in a population were the ones to evolve. E. C4 grasses replaced C3 trees and shrubs only in the areas that hominids had selectively burned.
A. Rapid evolution occurred because habitat alteration put new demands on our ancestors, and those ancestors with traits best adapted to these new conditions were the ones to survive.
How does the collision of continents change global sea level? A. Sea level falls as the ocean basins get larger. B. Sea level falls as volcanic activity evaporates ocean water. C. Sea level rises as continental crust subducts. D. Sea level rises as precipitation rates increase. E. None of the answers is correct.
A. Sea level falls as the ocean basins get larger.
Which of the following statements about subtropical ocean gyres is not true? A. Sea level in the middle of a gyre is 2 meters lower than the surrounding ocean. B. Gyre circulation is influenced by atmospheric winds, the Coriolis effect, and continental boundaries. C. Gyres circulate in a clockwise fashion in the Northern Hemisphere. D. The volume of water circulating in gyres is far greater than the combined flow of all of Earth's rivers. E. None of the answers is true.
A. Sea level in the middle of a gyre is 2 meters lower than the surrounding ocean.
Examine the following figure and determine which statement correctly describes the information shown. A. Snow and ice can accumulate at a mean annual temperature below 10°C. B. Rates of snow and ice accumulation are highest when it is the coldest. C. At about 1°C mean annual temperature, the rates of accumulation and ablation are equal. D. All of the answers are correct. E. Both A and B are correct.
A. Snow and ice can accumulate at a mean annual temperature below 10°C.
Which of the following is an example of a nonlinear response of the climate system to insolation? A. The amount of rainfall in North Africa is highly sensitive to insolation changes in summer but not in winter. B. The annual precipitation produced by monsoonal circulation depends equally on insolation changes in summer and winter. C. Orbital scale changes in insolation occur only in the summer months. D. In terms of calculating annual rainfall, a stronger winter monsoon cancels out the effects of a stronger summer monsoon. E. All of the answers are correct.
A. The amount of rainfall in North Africa is highly sensitive to insolation changes in summer but not in winter.
Examine the following figure and determine which of the following statements is correct. A. The average rate of seafloor spreading slowed between 50 and 15 million years ago, but it has since increased slightly. B. The average rate of seafloor spreading is higher today than any time in the last 50 million years. C. The rate of mid-plate volcanism was greater than the rate of spreading 30 million years ago. D. The trends in mid-plate volcanism and spreading rate since 15 million years ago should have led to a decrease in atmospheric CO2 levels. E. Both A and D are correct.
A. The average rate of seafloor spreading slowed between 50 and 15 million years ago, but it has since increased slightly.
How do higher sea levels affect climate? A. The high heat capacity of the water flooding the continents produces mild winters and cooler summers. B. The loss of high heat capacity of the flooded land produces more extreme seasonal conditions. C. Higher sea level promotes continental glaciation. D. All of the answers are correct. E. Both B and C are correct.
A. The high heat capacity of the water flooding the continents produces mild winters and cooler summers.
What allows lithospheric slabs to move? A. a soft, easily deformed layer of the mantle just below the lithosphere B. wind strength and direction C. incoming solar radiation D. formation and location of mountain uplift E. flow of material in the outer core
A. a soft, easily deformed layer of the mantle just below the lithosphere
A negative magnetic anomaly indicates: A. a time period of reversed polarity in geologic record. B. the position of a continent. C. that Earth's magnetic field at the time the rock formed was aligned similar to that of today's magnetic field. D. None of the answers is correct. E. Both B and C are correct.
A. a time period of reversed polarity in geologic record.
Orbital forcing can explain: A. about 0.1°C of the cooling between the years 1000 and 1850 in the high northern latitudes. B. all of the cooling between the years 1000 and 1800 in the high northern latitudes. C. none of the cooling between the years 1000 and 1800 in the high northern latitudes. D. All of the warming in the last century. E. Both A and D are correct.
A. about 0.1°C of the cooling between the years 1000 and 1850 in the high northern latitudes.
Ocean sediment: A. can be used to reconstruct climate on land. B. distribution patterns remain constant over geologic time at any particular location on the seafloor. C. is a lower-quality climate archive than most records from land due to the high rate of erosion along the seafloor. D. All of the answers are correct. E. None of the answers is correct.
A. can be used to reconstruct climate on land.
Mg/Ca ratios in foraminifera shells: A. depend on the temperature of the sea water. B. contradict the climate change results from δ18O measurements. C. show a large warming step after 40 Myr ago. D. All of the answers are correct. E. Both B and C are correct.
A. depend on the temperature of the sea water.
The positive mode of the NAO: A. features low-atmospheric pressure near Iceland and high-atmospheric pressure near the Azores. B. features cool waters in the western subtropical North Atlantic Ocean. C. features weak westerly winds. D. best explains the Arctic sea ice retreat in the late 1990s. E. All of the answers are correct.
A. features low-atmospheric pressure near Iceland and high-atmospheric pressure near the Azores.
Orbital tuning: A. is a means of dating sediments based on the relationship between astronomically calculated insolation changes and monsoonal responses measured in sediments. B. requires no independent age-depth markers in the sediment sequence. C. is most easily applied to river sediment sequences. D. All of the answers are correct. E. Both A and B are correct.
A. is a means of dating sediments based on the relationship between astronomically calculated insolation changes and monsoonal responses measured in sediments.
The peripheral forebulge: A. is slowly sinking today. B. was once located directly under the ice sheet. C. produces a slower rise in sea level than the global average does. D. Both A and B are correct. E. All of the answers are correct.
A. is slowly sinking today.
Tectonic-scale processes affecting climate: A. occur at very slow rates. B. occur on human-time scales. C. initiate only negative feedbacks. D. will likely be the primary driver of climate change in the next 100 years. E. All of the answers are correct.
A. occur at very slow rates.
Which of the following would be an appropriate archive for reconstructing what the climate was like 50 million years ago? A. ocean sediments cores B. ice cores C. instrumental records D. tree rings E. All answers but C are correct.
A. ocean sediments cores
Which of the following is true about a CO2 feedback at the 41,000 year cycle? A. positive feedback that doubled the strength of insolation-driven ice response at 41,000 years would make this the dominant cycle. B. It is clearly understood why CO2 acts as a feedback at the 41,000 year cycle but not the 23,000 year cycle. C. The relative heating effects due to greenhouse gas changes is estimated to be much stronger than insolation changes. D. All of the answers are true about CO2. E. None of the answers is correct.
A. positive feedback that doubled the strength of insolation-driven ice response at 41,000 years would make this the dominant cycle.
What is hypothesized to have occurred ~5000 years ago that could explain the CH4 trend? A. spread of rice irrigation in Southeast Asia B. a change in the orbital cycle C. increased deforestation in Europe D. a glaciation E. a plague
A. spread of rice irrigation in Southeast Asia
When did the evolutional line of human ancestors diverge from primitive apes? A. 200,000 years ago B. 6-4 million years ago C. 3-2 million years ago D. 12-10 million years ago E. 1 million years ago
B. 6-4 million years ago
Which of the following correctly describes the relationship between mean annual temperature and leaf shape? A. Plants with smooth-edged leaves cause temperatures to warm. B. As the temperature warms, there is an increase in the percentage of plants with smooth-edged leaves. C. Cooler temperatures result in more plants with smooth-edged leaves. D. All of the answers are correct. E. Both A and B are correct.
B. As the temperature warms, there is an increase in the percentage of plants with smooth-edged leaves.
Examine the following figure and determine which of the following statements is a logical interpretation of the southeast Minnesota lake pollen record. A. Climate was warmest between ~12,000 and 10,000 years ago. B. Climate at ~6,000 years ago was drier than today. C. Climate was the coolest between ~5000 and ~1000 years ago. D. There is more spruce than oak in southeast Minnesota today. E. Both A and C are correct.
B. Climate at ~6,000 years ago was drier than today.
Rapid changes between extremely cold stadials and relatively mild interstadials are referred to as: A. bond cycles. B. Dansgaard-Oeschger oscillations. C. Heinrich events. D. sediment drifts. E. None of the answers is correct.
B. Dansgaard-Oeschger oscillations.
Why is correlation of millennial events so challenging? A. Correlations can only be made between geologic archives of the same type. B. Dating uncertainties can be comparable in size to the length of the oscillation itself. C. Unless the oscillation was observed by humans, correlations are not able to be made. D. All of the answers are correct. E. None of the answers is correct.
B. Dating uncertainties can be comparable in size to the length of the oscillation itself.
How were people in northern Europe affected by temperature trends during the period 1400-1900? A. Crop output in far northern regions increased. B. Lakes, rivers, and ports froze during winter. C. Settlements became established in far southwestern Greenland. D. Both A and C are correct. E. None of the answers is correct.
B. Lakes, rivers, and ports froze during winter.
What do sensitivity experiments show about atmospheric CO2 concentrations above 1,000 ppm? A. Concentrations that high have never happened in Earth's history. B. Large ice sheets cannot exist when CO2 concentrations are that high. C. Mean annual temperatures remain below 20°C even at that level of CO2. D. Such concentrations cannot occur because of CO2 saturation. E. None of the answers are correct.
B. Large ice sheets cannot exist when CO2 concentrations are that high.
Numerical simulations of past climate occur in an ordered three-step sequence. The order is: A. Run a climate simulation → Specify boundary conditions → Analyze the climate data output by comparing them with independent geologic data. B. Specify boundary conditions → Run a climate simulation → Analyze the climate data output by comparing them with independent geologic data. C. Analyze the climate data output by comparing them with independent geologic data → Specify boundary conditions → Run a climate simulation. D. Run a climate simulation → Analyze the climate data output by comparing them with independent geologic data → Specify boundary conditions. E. None of the answers is correct.
B. Specify boundary conditions → Run a climate simulation → Analyze the climate data output by comparing them with independent geologic data
Why are the rates of photosynthesis in sunlit surface ocean waters limited? A. Sunlight cannot penetrate below the top 1 m of water. B. Surface waters are depleted of nutrients when phytoplankton die and sink to deeper waters. C. There is no photosynthesizing plant life in the surface oceans. D. There is very little CO2 in surface ocean waters. E. All of the answers are correct.
B. Surface waters are depleted of nutrients when phytoplankton die and sink to deeper waters.
Why is temperature more sensitive to changes in CO2 at the low-CO2 end than at the high CO2-end? A. There is a smaller albedo-temperature feedback at the low CO2-end. B. The direct radiative effect of CO2 is lower at the high CO2-end because CO2 saturation is approached. C. The heat capacity of the oceans increases with higher CO2-levels. D. All of the answers are correct. E. Both A and B are correct.
B. The direct radiative effect of CO2 is lower at the high CO2-end because CO2 saturation is approached.
Which of the following climatic conditions characterize the last glacial maximum? A. Ice sheets 10 km thick covered Canada. B. The global sea level was 110-125 m lower than today. C. The climate was humid, and there was high precipitation. D. All of the answers characterize the last glacial maximum. E. Both A and B are correct.
B. The global sea level was 110-125 m lower than today.
Why is it hard to assess whether climate change affected human evolution? A. Humans didn't evolve until 2000 years ago. B. The human fossil record is sparse. C. Climate hasn't changed during the existence of humans. D. Climate records for this time are sparse. E. All of the answers are correct.
B. The human fossil record is sparse.
Why is a "spin-up" interval necessary when altering boundary conditions in an A-GCM? A. The model requires large amounts of stored power to achieve the simulation. B. The model requires simulated time to reach a state of equilibrium. C. The model simulations start slowly and pick up speed through time. D. Both A and C are correct. E. All of the answers are correct.
B. The model requires simulated time to reach a state of equilibrium.
Examine the following figure and determine which of the following statements describes the greenhouse gas data comparing the current interglaciations with the previous several interglaciations. A. CO2 and CH4 show the same basic increasing trend in the latter part of all interglaciations. B. The trend of greenhouse gases in the present interglaciations is anomalous in the context of the previous several interglaciations. C. The atmospheric concentration of CH4 was greater 10,000 years ago than that of CO2. D. All of the answers are correct. E. Both B and C are correct.
B. The trend of greenhouse gases in the present interglaciations is anomalous in the context of the previous several interglaciations.
Examine the following figure. A highly eccentric orbit would occur when: A. a and b are equal. B. a is much larger than b. C. ε = 0. D. the orbit is circular. E. Both A and D are correct.
B. a is much larger than b.
Which of the following has the greatest influence on ice sheets size? A. accumulation in the winter B. ablation in the summer C. the density of ice crystals D. insolation in the winter E. Both A and D are correct.
B. ablation in the summer
An increase in the burial of organic carbon in coastal margins: A. should increase atmospheric CO2 levels. B. can result from increased upwelling and biological productivity. C. is a component of the uplift-weathering hypothesis. D. is hypothesized to result in atmospheric warming. E. Both A and D are correct.
B. can result from increased upwelling and biological productivity.
What do you get when you combine rainwater with atmospheric CO2? A. calcium carbonate B. carbonic acid C. organic carbon D. radiocarbon E. All of the answers are correct.
B. carbonic acid
What is the most important contributor to the δ18O signal in marine foraminifera over the last one million years? A. changing temperature of ocean water B. changing volume of ice sheets C. rate of volcanic activity in oceanic spreading centers D. source of continental bedrock for chemical weathering E. None of the answers is correct.
B. changing volume of ice sheets
The snowball Earth hypothesis: A. disproves the Gaia hypothesis. B. describes a period between 750 and 580 million years ago, during which continental glaciation was widespread, including in the tropics. C. can be easily explained through the regulation of climate by the chemical weathering. D. All of the answers are correct. E. None of the answers is correct.
B. describes a period between 750 and 580 million years ago, during which continental glaciation was widespread, including in the tropics
What is responsible for halos of dead lichen on Baffin Island? . A. fire during the medieval warm period B. expanded snowfields during the Little Ice Age C. extreme cold during the Little Ice Age D. high temperatures during the medieval warm period E. None of the answers is correct.
B. expanded snowfields during the Little Ice Age
Over the last 150 years, what has moved the most rock and soil per year? A. water B. humans C. submarine landslides D. ice E. wind
B. humans
Dendrochronology studies: A. require that scientists cut trees down, examining the ring structures in the stumps of the trees. B. involve the comparison of tree ring width and density to local records of instrumental rainfall and temperature. C. are only effective for reconstructing climate changes occurring over the last few decades. D. All of the answers are correct. E. Both A and B are correct.
B. involve the comparison of tree ring width and density to local records of instrumental rainfall and temperature.
Chemical weathering of continental rocks: A. is accelerated in cold, dry climates. B. involves chemical interactions between the soil/rock and atmospheric CO2 and H2O. C. produces ions that are most commonly transported to the deep sea via eolian processes. D. supplies ions to the deep sea, which pollute the waters making it difficult for ocean plankton to thrive. E. None of the answers is correct.
B. involves chemical interactions between the soil/rock and atmospheric CO2 and H2O.
The first evidence of agriculture: A. dates to 120,000 years ago. B. is based on non-native grains found in the Middle East. C. indicates homo erectus was the first of the human ancestors to cultivate crops. D. All of the answers are correct. E. Both B and C are correct.
B. is based on non-native grains found in the Middle East.
Atmospheric water vapor: A. is part of a negative feedback, in which more water vapor leads to cooler temperatures. B. is the most important greenhouse gas in the atmosphere today. C. is controlled by chemical weathering. D. concentrations are fairly uniform globally. E. None of the answers is correct.
B. is the most important greenhouse gas in the atmosphere today.
What was the main cause of tropical cooling during the last glacial maximum? A. direct thermal impact from ice sheets B. lower greenhouse gas concentrations C. reduced solar insolation D. All of the answers are correct. E. None of the answers is correct.
B. lower greenhouse gas concentrations
The bipolar seesaw: A. describes the out-of-phase pattern in millennial temperatures between the tropics and the poles. B. may result from changes in the northward redistribution of heat by the Atlantic Ocean circulation. C. may be driven by cyclic changes in obliquity. D. All of the answers are correct. E. Both A and B are correct.
B. may result from changes in the northward redistribution of heat by the Atlantic Ocean circulation
Which of the following climatic effects would be expected during times of rising global sea level? A. harsh, arid conditions in continental interiors B. mild maritime climates shifting toward the interior of continents C. more extreme temperature conditions globally D. onset of glacial conditions E. All of the answers are correct.
B. mild maritime climates shifting toward the interior of continents
To where did the extra CO2 from Earth's early atmosphere ultimately go? A. land plants B. sediments and rocks C. space, where it slowly diffused D. the ocean, where it dissolved E. marine life
B. sediments and rocks
Under the uplift weathering hypothesis, what is the main factor that influences the global rate of chemical weathering? A. the rate of seafloor spreading B. the amount of fresh rock exposed at Earth's surface C. mean temperature D. the atmospheric concentration of CO2 E. precipitation rates
B. the amount of fresh rock exposed at Earth's surface
In Earth's climate system, the term longwave radiation refers to: A. the incoming solar radiation received by Earth. B. the back radiation emitted by Earth. C. the albedo of Earth. D. radiation reflected by Earth's atmosphere. E. Both A and D are correct.
B. the back radiation emitted by Earth.
What is the "climate point" of an ice sheet? A. the elevation boundary between positive mass balance and negative mass balance B. the latitude where the equilibrium line intersects the Earth's surface C. the lowest latitude reached by flowing ice D. the point in time when an ice sheet switches from net accumulation to net ablation E. None of the answers is correct.
B. the latitude where the equilibrium line intersects the Earth's surface
Climate change 55 Myr ago is relevant to studies of modern and future climate because: A. it proves humans have no significant influence over modern climate. B. the relatively rapid input of carbon to the atmosphere is common to both the warming at 55 Ma and today. C. the main cause of the modern warming is the destabilization of methane clathrates, which is what happened 55 Myr ago. D. it shows that climate remains stable once a system threshold is passed. E. Both A and B are correct.
B. the relatively rapid input of carbon to the atmosphere is common to both the warming at 55 Ma and today.
Assume no ice sheets existed on Earth during the time period under investigation, and δ18O values measured from foraminifera shells decreased by 10/00. This result indicates a: A. cooling of 4.2ºC in the ocean. B. warming of 4.2ºC in the ocean. C. cooling of 2.1ºC in the ocean. D. cooling of 0.5ºC in the atmosphere. E. warming of 2.1ºC in the ocean.
B. warming of 4.2ºC in the ocean.
What scientific evidence supports the Black Sea flood hypothesis? A. There is geophysical evidence of a now-buried gorge between the Atlantic Ocean and the Mediterranean Sea. B. Saltwater mollusks were replaced by freshwater mollusks ~7600 years ago in the Black Sea. C. A deep pool exists where the Bosporus meets the Black Sea. D. All of the answers are correct. E. None of the answers is correct.
C. A deep pool exists where the Bosporus meets the Black Sea.
Why do most strong monsoons occur in the Northern Hemisphere rather than the Southern Hemisphere? A. Areas of high elevation are less extensive in the Northern Hemisphere. B. Insolation varies more in the Northern Hemisphere. C. Landmasses are larger in the Northern Hemisphere. D. There is more water vapor in the Northern Hemisphere. E. All of the answers are correct.
C. Landmasses are larger in the Northern Hemisphere.
Examine the following figure and determine which of the following statements is a logical interpretation of the modern pollen distribution data. A. Pollen distribution is controlled by temperature but not by precipitation. B. Prairie grasses prefer wet conditions, while oak trees prefer dry conditions. C. Spruce trees are most common in the northeast. D. Oak trees are more cold-tolerant than spruce trees. E. Both B and D are correct.
C. Spruce trees are most common in the northeast.
Examine the following figure and determine which of the following statements is correct. A. An increase in sulfate concentration causes volcanoes to explode. B. There have been more volcanic explosions on average since 1900 than during the previous two centuries. C. Sulfate concentrations were lower in 1990 than in 1980. D. The baseline sulfate concentration increased because volcanic eruptions increased. E. Both B and D are correct.
C. Sulfate concentrations were lower in 1990 than in 1980.
Examine the following figures which show integrated signals for temperature change based on tree ring analyses in the circum-Arctic and in Central Asia to determine which of the following statements is correct. A. The Arctic experienced sustained cold temperatures during the Little Ice Age. B. Central Asia experienced sustained cold temperatures during the Little Ice Age. C. The climate trends of the circum-Arctic and Central Asia show a similar pattern over the last 320 years. D. All of the answers are correct. E. None of the answers is correct.
C. The climate trends of the circum-Arctic and Central Asia show a similar pattern over the last 320 years.
What natural event may be responsible for the sudden collapse of the Mayan civilization on the Yucatan Peninsula in Mexico in 860? A. glacial advance B. flood C. drought D. volcanic eruption E. temperature rise/global warming
C. drought
The primary reason the surface of Venus is much hotter than that of Earth is because Venus: A. has a greater average albedo than does Earth. B. is closer to the Sun than is Earth. C. has greater levels of CO2 in the atmosphere than does Earth. D. is a larger planet than Earth. E. None of the answers is correct.
C. has greater levels of CO2 in the atmosphere than does Earth.
Sun spots: A. occur in a 100-year cycle. B. were more numerous between 1645 and 1715 than today. C. occur at times when net solar emissions are stronger than normal. D. cause changes in the amount of back radiation that Earth emits. E. All of the answers are correct.
C. occur at times when net solar emissions are stronger than normal.
he BLAG spreading rate hypothesis proposes how: A. Pangaea formed. B. continents move into polar positions. C. plate tectonic-control processes controlled CO2 atmosphere and ocean input, and thus influenced long-term global climate trends. D. hot spots form. E. Both A and B are correct.
C. plate tectonic-control processes controlled CO2 atmosphere and ocean input, and thus influenced long-term global climate trends.
Why is the land surface rising in the Hudson Bay region of Canada? A. accelerated heat flow from the upper mantle B. rapid elastic rebound due to recent loss of ice C. slow viscous rebound in response to ice melting over 10,000 years ago D. tectonic uplift due to converging lithospheric plates E. None of the answers is correct.
C. slow viscous rebound in response to ice melting over 10,000 years ago
Which of the following environmental effects of an asteroid impact would be expected to produce a cooling effect lasting days to years? A. increased levels of CO2 in the atmosphere B. shock waves circling the globe C. soot and dust injected into the stratosphere D. Both B and C are correct. E. All of the answers are correct.
C. soot and dust injected into the stratosphere
The savanna hypothesis: A. states that the spread of grasslands in Africa was a direct result of deforestation by early human ancestors. B. bases the increase in the growth of hominid braincases on a diet rich in prairie grasses such as wheat. C. suggests that human evolution was driven by a long-term drying of African climates. D. states that desert dust storms were impeded by the expansion of grasslands in North Africa 4 million years ago. E. attempts to explain why conditions became drier in Central Africa in the last 4 million years.
C. suggests that human evolution was driven by a long-term drying of African climates.
According to the Milankovitch's theory, what season of insolation is most important in controlling the growth and melting of ice sheets? A. fall B. spring C. summer D. winter E. They are all equally important.
C. summer
Earth's seasons are caused by: A. the distance between Earth and the Sun. B. the interaction of the Moon and Sun on Earth's orbit. C. the changing position of the tilted Earth with respect to the Sun. D. the movement of the Sun from north to south of the equator and back again over a year's time. E. the rate of Earth's movement around the Sun.
C. the changing position of the tilted Earth with respect to the Sun.
If Earth's axis had no tilt,: A. seasonal change in solar energy at Earth's surface would be maximized. B. solstices and equinoxes would be well-defined. C. the overhead Sun would always be at the equator. D. the poles would alternate between day-long darkness and day-long sunlight over the course of the year. E. None of the answers is correct.
C. the overhead Sun would always be at the equator.
During an El Niño event: A. the tropical eastern equatorial Pacific becomes cooler. B. upwelling is strong along Peru. C. the trade winds weaken. D. All of the answers are correct. E. Both B and C are correct.
C. the trade winds weaken.
Consider differential heating of the land and sea. For the same amount of solar radiation received on Earth, the surface ocean will: A. experience greater temperature range than the land. B. heat up faster than the land. C. transmit this heat to greater depths than the land will. D. All of the answers are correct. E. None of the answers is correct.
C. transmit this heat to greater depths than the land will.
When was the last glacial maximum? A. 10,000 years ago B. 120,000 years ago C. 5,000 years ago D. 21,000 years ago E. 240,000 years ago
D. 21,000 years ago
Under which conditions would you expect greater CO2 input to the atmosphere and ocean? A. fast seafloor spreading B. fast subduction C. during times of higher rates of hot spot volcanism D. All of the above conditions are correct. E. Both A and B are correct.
D. All of the above conditions are correct.
Cretaceous biota living in the high latitudes included: A. turtles and crocodiles. B. tropical broad-leafed evergreens. C. warm-adapted dinosaurs. D. All of the answers are correct. E. Both A and B are correct.
D. All of the answers are correct.
Examine the following figure to determine which of the interpretations of the insolation and δ180 data is reasonable. A. Insolation changes are dominated by a 23,000-cycle. B. Eccentricity modulation of the precession cycle results in very strong summer insolation about every 100,000 years. C. The strongest summer insolation peaks co-occur with rapid deglaciations. D. All of the answers are correct. E. Both B and C are correct
D. All of the answers are correct.
Glacial ice is a valuable climatic archive because: A. annual layers are often resolvable, enabling age determination and correlation. B. the ice contains geochemical proxies of atmospheric composition and temperature of the past. C. the geographic distribution of coring sites ranges from the tropics to both polar regions. D. All of the answers are correct. E. Both A and B are correct.
D. All of the answers are correct.
How could ice sheets have controlled CO2? A. Strong ice sheet-driven winds could transport iron-rich dust to the ocean, enhancing the biological carbon pump. B. Ice sheet-driven circulation of deep water changes could have resulted in a drop of CO3-2 ion concentrations in the south polar ocean, triggering a drawdown of CO2. C. Ice sheet-driven cooling of the ocean waters could have increased the solubility of CO2. D. All of the answers are correct. E. Both A and C are correct.
D. All of the answers are correct.
Oscillations of ice volume have occurred with what frequency over the last 150,000 years? A. 23,000 years B. 41,000 years C. 100,000 years D. All of the answers are correct. E. None of the answers is correct.
D. All of the answers are correct.
Rising CO2 levels: A. promote greater photosynthesis and thus tree growth. B. could complicate tree ring interpretations. C. would produce the same effect on the tree ring pattern as would a trend toward wetter climates in dry regions. D. All of the answers are correct. E. Both B and C are correct.
D. All of the answers are correct.
The long-term δ18O trend in benthic foraminifera indicate: A. > 6ºC cooling of the deep waters between 50-40 Myr ago. B. ice sheet growth after 40 Myr ago. C. > 7ºC cooling of the deep waters after 40 Myr ago. D. All of the answers are correct. E. Both B and C are correct.
D. All of the answers are correct.
The polar position hypothesis: A. maintains that ice sheets should appear on continents that were located at polar or near polar positions in the geologic past. B. maintains that no ice sheets should appear on continents located outside of the polar regions. C. only partially explains the sequence of icehouse and greenhouse intervals in the last 500 Myr. D. All of the answers are correct. E. Both A and C are correct.
D. All of the answers are correct.
The precession of the equinoxes results: A. from the wobble of Earth's spin axis. B. from the rotation of the actual orbital plane of Earth. C. in a shifting of the position of Earth along its orbit, such that 5,750 years from now the position of Earth at the spring equinox will be the same as its current position during the winter solstice. D. All of the answers are correct. E. Both A and B are correct.
D. All of the answers are correct.
What is the role of chemical weathering under the BLAG hypothesis? A. It is a negative feedback on atmospheric CO2 changes. B. Increases in atmospheric CO2 due to fast seafloor spreading ultimately lead to increased CO2 removal by chemical weathering. C. Warmer temperatures during times of increased volcanic activity cause an increase in the rate of chemical weathering. D. All of the answers are correct. E. None of the answers are correct.
D. All of the answers are correct.
What was responsible for mismatches between satellite and radiosonde data and surface measurements of the warming trend since 1980? A. Friction caused a drift in satellite orbit that altered the apparent location of satellite measurements. B. Overestimates of solar heating of radiosonde shields imposed a false cooling signal on the measurements. C. Overestimates of stratospheric cooling reduced the apparent tropospheric temperature measured by satellites. D. All of the answers are correct. E. None of the answers is correct.
D. All of the answers are correct.
What was the source area for the millennial ice-rafted debris events that are recorded in the North Atlantic? A. Limestone debris was derived from the Hudson Bay of Canada. B. Volcanic debris was derived from Iceland. C. Iron-stained debris was derived from northern Greenland, eastern Canada, and Europe. D. All of the answers are correct. E. Both A and B are correct.
D. All of the answers are correct.
Which of the following types of climate data has been measured with satellites? A. snow cover in the Northern Hemisphere B. sea ice cover in the Arctic C. thickness of the Greenland ice sheet D. All of the answers are correct. E. Both A and B are correct.
D. All of the answers are correct.
Which types of historical records reflect aspects of climate change? A. crop reports B. records of river freeze-up C. ships' logs of fish catches D. All of the answers are correct. E. Both A and B are correct
D. All of the answers are correct.
What physical evidence supports a dirtier (dustier) glacial world compared to that of today? A. extensive loess deposits in China B. layers of dust in Antarctic ice cores C. higher accumulation rates of dust in the Indian Ocean D. All of the answers are evidence. E. Both B and C are correct.
D. All of the answers are evidence.
Which of the following conditions increase the rate of chemical weathering? A. warming temperature B. increasing precipitation C. abundant vegetation D. All of the conditions increase the rate. E. None of the answers because these all decrease the rate of chemical weathering.
D. All of the conditions increase the rate.
During each yearly revolution around the Sun: A. Earth maintains a constant angle of tilt. B. Earth maintains a constant direction of this tilt in space. C. the northern axis of Earth's orbit is directed toward the Sun. D. Both A and B are correct. E. None of the answers is correct.
D. Both A and B are correct.
What effect does land clearance have on global climate? A. It has produced a small net warming of the planet. B. It produces cooling at high and middle latitudes through changes in albedo. C. It produces warming at tropical and subtropical latitudes by drying out land surfaces. D. Both B and C are correct. E. All of the answers are correct.
D. Both B and C are correct.
Which of the following is NOT a way northern hemisphere ice sheets could affect climate in the Southern Hemisphere? A. By changing the strength of deep-water circulation and the related heat transfer, they could affect the climate in the Southern Hemisphere. B. By changing global sea level which affects flooding and exposure of coastal regions, they could affect the climate in the Southern Hemisphere. C. By driving global variations in atmospheric greenhouse gases, they could affect the climate there. D. By increasing the wind strength across the equator, they could affect the climate in the Southern Hemisphere. E. These are all ways northern hemisphere ice sheets do influence climate in the Southern Hemisphere.
D. By increasing the wind strength across the equator, they could affect the climate in the Southern Hemisphere.
How will cloud cover on Earth change as greenhouse gas concentrations increase? A. Less cloud coverage will result from the atmosphere's increased capacity to hold water vapor. B. Fewer clouds will result as water vapor is destroyed at warmer temperatures. C. More cloud coverage will result from higher rates of evaporation. D. It is not presently possible to predict whether it will increase or decrease overall. E. More clouds will result as CO2 condenses to liquid at higher atmospheric concentrations.
D. It is not presently possible to predict whether it will increase or decrease overall.
Which of the following is a feature of Earth's eccentric orbit? A. The orbit of Earth around the Sun has a single focus. B. Perihelion and aphelion positions are at equal distances from the Sun. C. The Earth is currently farther from the Sun in January than it is in July. D. The interval of time from March 20 to September 22 is longer than from September 22 to March 20. E. All of the features are correct.
D. The interval of time from March 20 to September 22 is longer than from September 22 to March 20.
Which of the following statements about subtropical ocean gyres is not true? A. Ablation exceeds accumulation. B. The glacier is shrinking. C. The mean annual temperature at the highest elevation of the ice sheet is -5°C. D. The overall snowfall rate is greater than ice loss through melting and calving. E. All of the cases would be positive.
D. The overall snowfall rate is greater than ice loss through melting and calving.
How did geological data of temperatures during the Cretaceous and during the last glacial maximum, respectively, fit the GCM CO2 sensitivity models? A. There was sensitivity outside the model range for both periods. B. There was sensitivity toward the high end of the model range in the Cretaceous and toward the low end during the last glacial maximum. C. There was sensitivity toward the low end of the model range for both periods. D. There was sensitivity toward the high end of the model range for both periods. E. There was sensitivity at the middle range of the model for both periods.
D. There was sensitivity toward the high end of the model range for both periods.
The enrichment of 18O in ocean waters as 16O is preferentially stored in snow, and ice is an example of a process called: A. accumulation. B. condensation. C. foraminifera. D. fractionation. E. None of the answers is correct.
D. fractionation.
The effect of the combined movement of axial precession and precession of the ellipse is called what? A. axial rotation B. eccentricity C. obliquity D. precession of the equinoxes E. None of the answers is correct.
D. precession of the equinoxes
What evidence suggests the Nile River was once fed by flowing streams from the present-day Sahara Desert? A. an absence of surface sand along the ancient stream courses B. modern river channels following the same course C. oxygenated layers of sediment in the Mediterranean Sea D. river deposits buried by sheets of sand and detected by satellite E. All of the answers are correct.
D. river deposits buried by sheets of sand and detected by satellite
Which of the following is the largest reservoir of carbon in the Earth system today? A. soils B. the atmosphere C. the ocean D. sediments and rocks E. continental vegetation
D. sediments and rocks
What evidence did Alfred Wegener present to support his hypothesis of the mobility of continents? A. magnetic reversals of oceanic crust B. paleomagnetism of continental rock C. radiometric age of ocean crust D. similar shapes of widely separated continental margins E. All of the answers are correct.
D. similar shapes of widely separated continental margins
The view that millennial fluctuations of the climate system behave in a fashion somewhere between random and cyclical is called: A. oscillatory behavior. B. periodicity. C. red noise. D. stochastic resonance. E. None of the answers is correct.
D. stochastic resonance.
The Drake's Passage gateway hypothesis: A. argues that more poleward heat flow occurred after the opening of the gateway. B. is supported by sensitivity tests with climate models. C. relies on the transport of more oceanic moisture to Antarctica to explain the growth of ice sheets. D. suggests that the separation of Antarctica from Australia and South America allowed ice sheets to form on Antarctica. E. None of the answers is correct.
D. suggests that the separation of Antarctica from Australia and South America allowed ice sheets to form on Antarctica.
Which of the following causes relative global sea level to rise? A. slower rates of seafloor spreading B. global cooling C. ice sheet formation D. thermal expansion of water molecules E. Both B and C are correct.
D. thermal expansion of water molecules
Dating, and therefore correlation, of different sediment sequences may be accomplished using: A. radiometric dating of unstable isotopes. B. the fossil record (i.e., biostratigraphy). C. identification of a marker bed, such as a distinct ash layer. D. orbital tuning. E. All of the answers are correct.
E. All of the answers are correct.
Examine the following figure showing δ18O signals from CaCO3 cave deposits in Brazil and China and determine which statement is correct. A. Both records show a 23,000-year periodicity. B. The δ18O variation has the phase of midsummer insolation in China. C. The δ18O variation has the phase of midsummer insolation in Brazil. D. Both A and B are correct. E. All of the answers are correct.
E. All of the answers are correct.
How do ice sheets act as an internal driver of the climate system? A. Large ice sheets lower the temperature of the adjacent ocean with no lag time. B. Large ice sheets lower the surface air temperature above land downwind. C. Large ice sheets increase the strength of the winds. D. Large ice sheets affect high and mid-latitude climates the most during the winter months. E. All of the answers are correct.
E. All of the answers are correct.
How do periods of stronger North African monsoons change the characteristics of sediments in the Mediterranean Sea? A. Deep Mediterranean waters stagnate. B. Iron sulfide deposition is enhanced. C. Mediterranean bottom waters become anoxic. D. They favor the production of organic-rich muds called sapropels. E. All of the answers are correct.
E. All of the answers are correct.
Ice core data from the Quelccaya ice cap in Peru: A.show a shift toward more positive δ18O values near 1900. B.show a shift toward less dust near 1900. C.show relatively positive values of δ18O in the ice from 1000 to 1400. D.are currently being homogenized by the recent melting of the ice cap. E. All of the answers are correct.
E. All of the answers are correct.
Obliquity: A. has a dominant cycle of 41,000 years. B. ranges from ~22.5 to ~24.5 degrees tilt. C. variations amplify or suppress the seasons, especially in the high latitudes. D. Both A and B are correct. E. All of the answers are correct.
E. All of the answers are correct.
Sediment eroded by glaciers is transported by: A. streams and rivers. B. icebergs. C. winds. D. the glacier itself. E. All of the answers are correct.
E. All of the answers are correct.
The tectonic uplift of the Tibetan Plateau and the Himalayas: A. produced a unique high elevation area in the Cenozoic. B. resulted in increased rates of sediment accumulation in the northern Indian Ocean. C. resulted in the development of a strong monsoon system. D. occurred starting 55 million years ago. E. All of the answers are correct.
E. All of the answers are correct.
Urban heat islands: A. have greater back radiation at night. B. have greater absorption of incoming radiation during the day. C. have higher temperatures than rural regions do, given the same incoming radiation. D. contributed to instrumental observations of warming of the last century. E. All of the answers are correct.
E. All of the answers are correct.
What factor tends to complicate spectral analysis when it is used on real climate data? A. Errors in dating climate records spread power over a range of periods. B. Measurement of amplitude in climate records is subject to error. C. Most cycles are not perfect sine waves. D. Random noise exists in the climate system. E. All of the answers are correct.
E. All of the answers are correct.
What leads to ice ablation? A. calving B. incoming solar radiation C. uptake of latent heat D. uptake of sensible heat E. All of the answers are correct.
E. All of the answers are correct.
Which of the following influences the rate of 14C production? A. cosmic-ray bombardment of Earth's atmosphere B. the strength of Earth's magnetic field C. the strength of the solar wind D. Both B and C are correct. E. All of the answers are correct.
E. All of the answers are correct.
Which of the following is true of conditions in North America during periods of millennial oscillations of climate? A. Glaciers in many mountain ranges advanced at millennial timescales. B. Lake Bonneville levels reached maxima at the same time that ice-rafting events occurred in the North Atlantic. C. The southern margin of the Laurentide ice sheet fluctuated at about the same time as ice-rafting events in the North Atlantic. D. Wetter conditions occurred in Florida during ice-rafting events in the North Atlantic. E. All of the answers are correct.
E. All of the answers are correct.
Which of the following is true of glaciation in the Northern Hemisphere between 2.75 and 0.9 million years ago? A. At least forty glaciations occurred during this period. B. Glacial episodes occurred at a dominant 41,000 year cycle. C. Gradual underlying cooling took place. D. Both A and B are correct. E. All of the answers are correct.
E. All of the answers are correct.
Which of the following statements correctly describes the conceptual model of monsoonal response to orbitally-driven summer insolation changes at 30ºN, as shown in the following figure? A. Eleven-thousand years ago there should have been lakes in North Africa where there is desert today. B. When summer insolation values exceeded some threshold level, North Africa should have experienced stronger monsoonal circulation. C. Annual precipitation patterns in North Africa should show the 23,000-periodicity of a precession cycle over the last 140,000 years. D. The modulation of the precession signal by orbital eccentricity should have produced the strongest monsoons between 85,000 and 130,000 years ago. E. All of the answers are correct.
E. All of the answers are correct.
Which of the following was a distinctive development in the evolution of humans? A. the development of large brains in the Homo genus B. the onset of bipedalism C. the use of tools D. Both A and D are correct. E. All of the answers are correct.
E. All of the answers are correct.
Which of the following is true about reconstructions of the last glacial maximum climate in the southeastern United States? A. Model reconstructions do not fully take into account cooling of the Gulf of Mexico by glacial meltwater. B. Model reconstructions underrepresent the amount of cooling in the region. C. Model simulations indicate that warm-adapted trees should have been abundant throughout the region. D. Pollen evidence shows that warm-adapted elms were very restricted in distribution. E. All of the answers are true.
E. All of the answers are true.
What is the broad scientific benefit of projects like COHMAP and CLIMAP? A. Scientific problems can be better addressed in an interdisciplinary effort. B. Large synthesis datasets can be generated by collaborative teamwork. C. Only the scientists involved will have access to the results of the project investigation. D. All of the answers are benefits. E. Both A and B are benefits.
E. Both A and B are benefits.
Examine the following figure and determine which of the following statements correctly describes the CLIMAP reconstruction data for the last glacial maximum (LGM) shown in the figure. A. Equatorial surface ocean temperatures were cooler at the LGM than they are today. B. Surface ocean temperatures were colder in the North Atlantic at the LGM than they are today. C. Continental ice sheets were extensive in the Northern Hemisphere but were not present in the Southern Hemisphere. D. All of the answers are correct. E. Both A and B are correct.
E. Both A and B are correct.
Examine the ice core data in the following figure to determine which of the following statements is true. A. The average δ18O concentration in Greenland is more positive during the last 100 years than at any other time in the record. B. The average δ18O concentration in Tibet is more positive during the last 100 years than at any other time in the record. C. The average δ18O concentration in Antarctica is more positive during the last 100 years than at any other time in the record. D. All of the answers are correct. E. Both A and B are correct.
E. Both A and B are correct.
How are beds of volcanic ash used in studies of human evolution? A. Footprints of human ancestors have been preserved in volcanic ash. B. The age of fossil remains of human ancestors can be constrained by radiometric dating of interbedded volcanic ash layers. C. Volcanic ash has preserved whole skeletons of human ancestors, similar to those found in Pompeii. D. All of the answers are correct. E. Both A and B are correct.
E. Both A and B are correct.
The modern glacial ice: A. is more enriched in oxygen-18 than is the ocean. B. is more depleted in oxygen-16 than is the ocean. C. has the same oxygen-isotope signal as the ocean. D. None of the answers is correct. E. Both A and B are correct.
E. Both A and B are correct.
Magnetic lineations on the ocean floor: A. match the pattern of magnetic-reversal history from basalt sequences on land. B. are true stripes of black and white color variations on the ocean floor. C. can be used to reconstruct the rate of seafloor spreading. D. All of the answers are correct. E. Both A and C are correct.
E. Both A and C are correct.
What accounts for the sea level rise of the twentieth century? A. melting of sea ice B. melting of land-based ice C. thermal expansion of sea water D. Both A and B are correct. E. Both B and C are correct.
E. Both B and C are correct.
Chemical weathering by hydrolysis of silica-rich rocks on the continents: A. adds silica to the atmosphere. B. adds CO2 to the atmosphere. C. transfers carbon-containing ions to the ocean where they are later stored in the shells of marine plankton. D. transfers silica-containing ions to the ocean where they are later stored in the shells of marine plankton. E. Both C and D are correct.
E. Both C and D are correct.
What percent of the 0.8°C global warming since the late 1800s can be attributed to long-term tectonic-scale climatic forcing? A. 50% B. 25% C. 5% D. 1% E. Effectively none
E. Effectively none
Critics of global warming have strong supporting evidence in: A. radiosonde atmospheric temperature measurements. B. satellite estimates of sea surface temperature. C. satellite estimates of tropospheric temperature. D. All of the answers are correct. E. None of the above because the full range of instrumental and satellite data now indicate major warming occurred over the last century.
E. None of the above because the full range of instrumental and satellite data now indicate major warming occurred over the last century.
How did European vegetation respond to millennial oscillations in climate during the last glaciation? A. Soils became enriched with organic material during colder intervals. B. Trees and steppe grasses were replaced by tundra during warm intervals. C. Vegetation showed no response to the changes in temperature recorded in the North Atlantic and Greenland. D. Both A and B are correct. E. None of the answers is correct.
E. None of the answers is correct.
Millennial oscillations in climate: A. are controlled by orbital changes. B. are observed only in the North Atlantic. C. are observed in proxy climate records spanning only the last 1,000 years. D. have a regular periodicity of 1,000 years. E. None of the answers is correct.
E. None of the answers is correct.
How did freshwater diatoms end up in sediment cores taken from the tropical Atlantic Ocean? A. Monsoonal-strength winter winds carried diatoms from African lakes to the Atlantic Ocean. B. In the past the tropical Atlantic had a freshwater lid periodically, where these diatoms lived; dying, they sank to the seafloor below. C. The diatoms were carried out by ocean currents from the freshwater Mediterranean Sea. D. The diatoms were transported by turbidity flows from the Nile River. E. The diatoms lived in freshwater lakes in North Africa and were windblown to the North Atlantic by the NE trade winds sometime after the lakes dried up.
E. The diatoms lived in freshwater lakes in North Africa and were windblown to the North Atlantic by the NE trade winds sometime after the lakes dried up.
What is a glacial termination? A. an interglacial B. where the glacier meets the sea C. global warming D. any deglaciation E. deglaciations that occur at the end of a long, irregular (saw-toothed) ice growth phase
E. deglaciations that occur at the end of a long, irregular (saw-toothed) ice growth phase
Global dimming: A. is irreversible. B. will produce a solar eclipse. C. is caused by rising CO2 levels. D. is more prominent in polar regions. E. masks the effects of global warming.
E. masks the effects of global warming.
How do lichen serve as a climate proxy? A.Lichen grow at predictable rates. B.Extreme cold kills lichen. C. The distribution of lichen halos (dead lichen) indicate where snowfields existed in the past. D.All of the answers are correct. E.Both A and C are correct.
E.Both A and C are correct.
A gradual shift from C4 toward C3 vegetation in Africa suggests a long-term increase in monsoonal rainfall over the last 4 million years. True or False?
False
Climate signals from marine δ18O, tropical pollen, and loess deposits in China all show a dominant 41,000-year cycle for the last 0.9 million years. True or False?
False
Estimates of atmospheric CO2 levels over the last 50 million years show a major decrease after 10 million years ago. True or False?
False
Key evidence of an asteroid impact on Earth 65 million years ago includes a drop in sedimentary iridium in marine deposits around the world. True or False?
False
Latitudes near the equator experience much larger seasonal changes in solar radiation than mid- and high-latitudes. True or False?
False
Periods of global population decrease over the last 1,000 years were accompanied by abrupt rises in atmospheric CO2 concentration. True or False?
False
Photosynthetic organisms first appeared on Earth after atmospheric oxygen concentrations increased. True or False?
False
Rates of sediment deposition are typically lowest in deep-ocean settings. True or False?
False
Recent trends have shown that the Greenland ice sheet is at a stable overall mass balance. True or False?
False
Temperatures at Earth's surface commonly occur throughout a range of -150°C to +110°C. True or False?
False
The ability to walk upright evolved after the branching of the genus Homo from other hominins around 2.5 million years ago. True or False?
False
The effect of human activity on Earth's climate is not considered to be a climate forcing because it is not part of the natural climate system True or False?
False
The increase in glacial erosion that would accompany uplift constitutes a strong negative feedback on chemical weathering. True or False?
False
Thermal inertia of the oceans is likely partially responsible for the more-rapid-than-expected warming of global climate since the 1980s. True or False?
False
The uncertainties in temperature reconstructions of northern hemisphere temperatures over the last 1,000 years are due to the sparse coverage of sites and are much larger for the early part of the record. True or False?
True
What is unusual about the changes to the climate system that will occur over the next few centuries? a. The change in forcing will be faster than previous large changes in Earth history. b. Humans have never had an influence on the climate system before. c. Greenhouse gases have never before been a major forcing on the climate system d. Both B and C are correct. e. All of the answers are correct.
a. The change in forcing will be faster than previous large changes in Earth history.
Climate differs from weather in that climate: a. refers only to temperature conditions, while weather addresses temperature as well as precipitation, snow and ice cover, and wind conditions. b. is a broad composite of the average condition of a region, while weather fluctuations last a short time. c. is exclusively global, whereas weather is exclusively regional. d. and weather do not differ, they are interchangeable terms. e. All of the above are correct.
b. is a broad composite of the average condition of a region, while weather fluctuations last a short time.
What effect do mountain ranges have on the distribution of precipitation? a. Air is warmed as it rises up the side of a mountain, reducing precipitation rates. b. A rain shadow is produced on the side facing ocean winds. c. Precipitation is enhanced on the windward side and reduced on the leeward side. d. Water vapor is added to the atmosphere as it descends the leeward side, leading to wetter conditions. e. All of the answers are correct.
c. Precipitation is enhanced on the windward side and reduced on the leeward side.
What is a scientific theory? a. an "educated guess" that proposes an explanation for observations b. a proven truth that is no longer subject to testing c. an hypothesis that explains a wide array of observations and survives scientific testing over a period of time. d. a research question published in a scientific journal e. None of the answers is correct.
c. an hypothesis that explains a wide array of observations and survives scientific testing over a period of time.
Which of the following has the highest average albedo range? a. desert sand b. forest c. fresh snow or ice d. water e. All of the above are similar in albedo range.
c. fresh snow or ice
In which of the following areas would you expect upwelling of ocean water to occur? a. where sea ice forms b. where surface waters cool c. where surface winds blow parallel to coastlines d. where high evaporation rates increase surface salinity E. None of the answers is correct.
c. where surface winds blow parallel to coastlines
Which of the following is true about our understanding of the history of Earth? a. Earth formed 4.55 billion years ago. b. Our knowledge of conditions on Earth is clear for the entire span of Earth history. c. Early deposits that could give insight into Earth history have been eroded away. d. Both A and C are correct. e. All of the answers are true about our understanding.
d. Both A and C are correct.
What causes the observed annual rise and fall of carbon dioxide? a. annual patterns of deforestation and forest regrowth in the tropics b. seasonal changes in atmospheric circulation patterns c. seasonal changes in the rate of fossil fuel burning d. seasonal changes in the rates of photosynthesis and oxidation in the Northern Hemisphere e. None of the answers is correct.
d. seasonal changes in the rates of photosynthesis and oxidation in the Northern Hemisphere
What causes Earth's climate to change? a. changes in Earth's orbit around the Sun b. changes in the strength of the Sun c. changes in plate tectonics d. human activities e. All of these cause changes.
e. All of these cause changes.
Past climate change: a. informs scientists about climate drivers and system interactions, which are necessary for predicting future climate change. b. occurred only in the last 300 million years. c. has been influenced by both natural and anthropogenic drivers. d. All of the answers are correct. e. Both A and C are correct.
e. Both A and C are correct.