Unit 3: Earth's Climate and how it Changes

11. Which are external Earth factors that contribute to global climate change?

- Earth's orbit around the Sun - Earth's spinning on its axis - Earth's tilt toward the Sun

21. Initially, Earth's early atmosphere had very low levels of oxygen. What changed and how did it affect the global climate?

.25 of 1 - Single-celled organisms, like cyanobacteria, started to photosynthesize, which increased oxygen and decreased carbon dioxide. This changed the composition of the atmosphere and reduced the greenhouse effect. NOT - As Earth started to cool, more carbon dioxide dissolved in oceans and oceans released their oxygen, which impacted both oceanic and atmospheric conditions, which impacted global climate.

8. What is the function of a model in science?

A model provides a way to represent complex ideas, phenomena, or processes so that they can be better understood.

4. Two cities, X and Y, are positioned at the same latitude and elevation. One city is located near the coast and one city is located 300 km inland. The average yearly temperatures during summer and winter for these two cities are given in the table. Based on this information, which city is more likely the one located on the coast and what might account for the difference in its climate?

City X, because the temperature is more moderate due to the storage of heat by the nearby ocean.

2. A geological study has suggested that there may have been some water present on early Earth 4.45 billion years ago. However, Earth's oceans did not form until about 3.8 billion years ago.

Climatic conditions at 4.5 billion years were too hot for liquid water.

Consider the diagram of Earth's energy budget shown: Which arrow depicts an effect that contributes to climate change?

D

12. How might regional climate on Earth be different if Earth did not tilt on its axis during its orbit around the Sun?

Different regions of Earth would have the same continuous climate with no variability in seasons.

Which situation regarding Earth's energy budget will cause increased warming?

Incoming solar energy is greater than outgoing heat energy.

How does the natural greenhouse effect affect Earth's energy budget?

It creates an imbalance between incoming solar radiation and outgoing heat. Less energy is going out than is coming in.

7. Which describes the impact of El Niño and La Niña on weather patterns in the Atlantic Ocean?

NOT = Both El Niño and La Niña lead to increased hurricanes.

10. Which best describes how a change in the eccentricity of Earth's orbit around the Sun could result in a change in climate?

The eccentricity of Earth's orbit would bring Earth closer to or further away from the Sun and affect the amount of solar energy Earth receives.

6. Over the course of Earth's history to present day, how would land-based climate conditions have changed as existing continents spread apart?

There would have been an increase in variability of climate conditions on land as there was more exposure to seasonal climate changes.

How might a volcanic eruption be beneficial to global farming?

Volcanic ash is rich in nutrients and serves as a fertilizer to the soil.

17. Some Earth conditions exert both a cooling and warming effect on global climate. Match the identified Earth condition and effect with the correct description of why it causes the stated effect.

clouds warming = trap outgoing sunlight forests cooling = remove greenhouse gas clouds cooling = reflect incoming light forests warming = absorb more solar

When a food chain fails a desert ecosystem occurs.

false

15. Which is an internal naturally occurring Earth condition that contributes to climate change?

greenhouse effect

Which is an astronomical factor that affects Earth's climate?

the Milankovitch cycles

All levels of a food chain connect to the decomposers.

true

Food chains start with energy from the sun, captured by plants.

true

Food chains usually only have 4-5 levels.

true

What pattern of events that affects Earth's weather occurs because of the Sun's uneven heating of Earth's surfaces?

uneven heating → temperature gradient → pressure gradient → winds → ocean currents

Unit Session 3

week3

Oceans influence Earth's climate in part due to their ability to absorb heat. Why are oceans able to absorb more of the Sun's heat energy than land?

Oceans have a lower albedo than land and so absorb more of the incoming solar radiation.

5. How might the role of oceans in influencing climatic conditions on land compare during the time of the supercontinent Pangaea to today's continents?

Oceans played a smaller role during the time of Pangaea in moderating its climate as the supercontinent would have had less edges and more expansive land area.

5. Based on the diagram, what property of oceans best accounts for their effect on Earth's climate?

Ocean currents move warm water towards the poles and cool water towards the equator.

An El Niño year in northern Australia is similar to a La Niña year in the southern US because they both bring _[blank]_ waters to land and cause _[blank]_ weather conditions.

cooler, warmer and drier

7. Which are examples of naturally occurring Earth conditions that contribute to climate change?

greenhouse effect

Which property of water allows oceans to absorb more heat than land?

its high heat capacity

Match each type of scientific model with the example that best fits that model.

mathematical = weather forecast physical = a world globe conceptual = water cycle

24. Consider the changing landscape of Earth from 225 million years ago to present day: Which Earth conditions are likely to have changed as continental locations shifted from the Permian period to present day?

- ocean currents - regional climate zones

3. Select sentences that summarize key factors that allow oceans to have a significant influence on climate change.

- oceans have a higher capacity - the high heat capacity - oceans also have a lower albedo

25. Which best explains the impact on global climate of a massive volcanic eruption?

- It can have a cooling effect as it releases aerosol particles that block sunlight from Earth's atmosphere. - It can have a warming effect by trapping heat in Earth's atmosphere due to the emission of greenhouse gases.

10. Which situation regarding incoming solar energy and outgoing heat energy will result in changes in Earth's climate?

.25 of 1 - incoming heat energy slightly greater than outgoing solar energy - incoming solar energy greater than outgoing heat energy .25 of 1 - incoming heat energy equal to outgoing solar energy - incoming solar energy greater than outgoing heat energy

22. Which conditions of Earth, about 2 billion years ago, controlled its climate?

.25 of 1 - mass extinctions NOT - reducing atmosphere

Match each time period with the correct external cycle that contributes to Earth's climate.

11 years = solar 26,000 years = precession 41,000 years = obliquity 100,000 = eccentricity

Match each value for the angle of tilt of Earth's axis with the correct effect on climate.

22.1 = more similarity 23.0 = average difference 24.5 = most extreme difference

The 100% of solar radiation that comes to Earth is distributed as follows: What proportion of incoming solar radiation becomes available for heating Earth?

70% All processes involving absorption are available for heating Earth.

23. Early Earth's atmosphere had a lot of water vapor but no liquid water. What change in Earth's atmosphere allowed for oceans to form?

Earth started to cool so the water vapor condensed to liquid.

13. Scientists have found that the amount of energy Earth receives from the Sun has varied only slightly since the 1950s, ranging from a high of approximately 1361.7 W/m2 during the decade of the 1950s, to a low of approximately 1360.2 W/m2 over the decade of the 2010s, with regular peaks and lows during the 11-year solar cycle. However, over the same period, Earth's overall average temperature has increased by about 1°C. If Earth's climate were influenced only by the solar cycle, how would its climate have changed over the period from 1950 to 2020?

Earth's climate would have shown very little change as the Sun's energy during the solar cycle produced little variability.

Which are possible climatic consequences of the formation of the Isthmus of Panama?

- It created the Atlantic Gulf Stream taking warm waters northward and giving northwestern Europe a milder climate. - It changed the direction of ocean currents and therefore how global climate was moderated.

4. The graph shows variations in the amount (concentration) of atmospheric carbon dioxide over the period of 800,000 years ago to present day. What association can be made between atmospheric concentrations of carbon dioxide and global climate?

- Low concentrations of atmospheric carbon dioxide were associated with cold temperatures. - Global temperatures were warmer during periods of higher atmospheric carbon dioxide.

Which describes why the poles do not get as hot as the equator even when they tilt toward the Sun?

- Solar radiation is distributed over a larger area at the poles than at the equator due to the shape of Earth. - Incoming solar radiation still strikes the poles at an angle, whereas it is more direct at the equator.

Ocean currents generally follow a pattern of moving away from the equator along the eastern coast of continents and toward the equator along the western coast of continents. How might this pattern affect the climate of two South American cities which lie on the same line of latitude if one city is in Brazil and the other is in Chile?

- The Brazilian city is likely to be warmer than the Chilean city as its climate would be influenced by the warmer currents moving away from the equator.

The Great Oxygenation Event also led to the almost mass extinction of anaerobic cyanobacteria which were in part responsible for the event. What other events were also likely affected or triggered?

- The composition of oxygen in Earth's atmosphere increased and stabilized. - There was an increase in organisms which could use oxygen.

16. Which are true about the greenhouse effect?

- The greenhouse effect occurs naturally in energy interactions between the Earth and the Sun. - Outgoing heat energy from Earth's surfaces becomes trapped in the atmosphere.

What would possible impacts on global climatic conditions be if winds did not allow ocean currents to form?

- There would be greater extremes between climatic zones. - Oceans would not be able to move heat around Earth.

How would global climate be affected if Earth's orbital path did not include an axial precession?

- There would be similarity in the seasonal changes in both hemispheres. - The yearly timing of when the seasons actually begin would be more consistent.

19. Which conditions of very early Earth, about 4.5 billion years ago, controlled its climate?

- explosive volcanic eruptions - composition of its atmosphere

Which is a likely difference in the atmospheric composition during the Eocene period compared to the present?

- higher methane levels - higher carbon dioxide levels

3. What was the effect of the change in Earth's atmosphere from a reducing to an oxidizing one?

- it increased the atmosphere's oxygen content which could better support life. - it caused Earth to cool as there was less greenhouse gases present.

1. Which internal early Earth conditions about 4.5 billion years ago influenced its climate?

- its reducing atmosphere - frequent volcanic eruptions

9. Which are examples of types of models used in science?

- physical - conceptual - mathematical

Which describes how climate in equatorial regions is affected by Earth's obliquity?

Earth's obliquity causes little change in the climate of equatorial regions as they still receive similar solar insolation.

How do Earth's obliquity and precession affect climatic conditions?

Earth's obliquity causes the seasons to happen at the time of year they occur in each hemisphere, while its precession affects how extreme climatic conditions are during seasonal changes.

Climatic conditions on Earth soon after it formed were fiery hot. How did this affect the moderating effect of Earth's oceans?

Earth's oceans would not have any moderating effect as conditions were too hot for liquid water (and hence, oceans) to exist.

2. What accounts for the difference in climate conditions at the equator compared to the poles?

Earth's shape means that the Sun's energy comes in more directly—or perpendicular—to the equator, whereas the Sun's energy reaches the poles at an indirect angle, resulting in a difference in climate.

What accounts for climatic conditions becoming progressively cooler between the equator and the poles?

Earth's spherical shape, and the orientation of its spin axis in relation to the Sun's means that solar radiation comes in more directly at the equator and then gets progressively more indirect as you go toward the poles.

14. How is global climate affected by Earth's wobble on its axis as it orbits the Sun?

Earth's wobble causes relatively extreme seasonal changes in one hemisphere and moderate seasonal changes in the other.

18. Which best describes how changes in Earth's energy budget can result in climate change?

NOT = Earth's surfaces absorb about 70% of incoming solar radiation and re-emit it as heat. Variations in the amount of solar radiation and heat energy absorbed and emitted, as well as in how much heat may become trapped in Earth's crust and mantle, can result in climate change.

20. In a classroom, students were asked to identify very early Earth conditions, about 4.5 billion years ago, that contributed to climate change. One student identified the movement of ocean currents. Why is that answer incorrect?

Oceans had not formed yet so there would be no ocean currents.

1. How does the way the Sun heats the Earth affect Earth's weather?

The Sun's radiation unevenly heats Earth's surfaces, which then unevenly heat the air above them by conduction. This warm air rises and is replaced with cooler, denser air by convection, setting up the formation of air currents.

How does the way in which the Sun heats the Earth cause winds?

The Sun's uneven heating of Earth sets up a difference in temperature that causes the warmer air to rise. This, in turn, sets up an area of low pressure into which the cooler air rushes, causing wind.

8. Carbon dioxide, one of the main greenhouse gases, makes up approximately 0.03% of Earth's atmosphere and 95% of Mars' atmosphere. However, scientists have not observed any significant greenhouse effect on Mars. What accounts for this observed difference related to the greenhouse effect on Earth and Mars?

The atmosphere of Mars is much thinner than Earth's and so does not trap outgoing heat.

Which is the main reason for the use of models in science?

They make ideas or phenomena easier to understand.

In the Philippines in 1991, the eruption of Mount Pinatubo sent 20 million tons of sulfur dioxide particles as well as other aerosols into Earth's upper atmosphere. Average global temperatures were cited as falling by 0.50 C in the following year as the gas cloud was carried around the world.

Upper-level winds carried the aerosols worldwide, and in Earth's upper atmosphere their high albedo reflected incoming radiation back to space.

Which correctly describes the cause and resulting weather conditions in North America from an El Niño year?

Warm waters in the eastern Pacific lead to warmer-than-usual temperatures in the northern US and Canada and cooler, wet conditions in the southern US.

6. Match the weather event with the correct description related to the effect of the El Niño Southern Oscillation (ENSO), which occurs in the Pacific Ocean, on global weather.

Westward-blowing trade winds across the equatorial Pacific move warm surface ocean currents and moist air westward toward Australia. Near Australia, the warm air rises via convection, leading to rain, and returns eastward colder and drier. In the Americas, movement of the warm surface water westward causes an upwelling of colder ocean water. = neutral Westward-blowing trade winds across the equatorial Pacific strengthen, moving warm surface ocean currents and moist air further westward toward northern Australia and strengthening the upwelling of cold ocean water in the Americas. This results in increased rainfall, storms, floods in northern Australia, and drier, drought conditions in the Americas. = La Nina Westward-blowing trade winds across the equatorial Pacific weaken, causing warm surface ocean currents to shift eastward, moving warm water toward the Americas and causing an upwelling of cold water near Australia. This results in increased rainfall, storms, and floods in the Americas and droughts and increased wildfires in Australia. = el nino

9. Planting trees has been identified as a way to reduce the greenhouse effect and lessen the adverse effects of climate change. However, more trees might actually cause a warming effect in some environments. In which environment, the poles or the equator, are trees more likely to have a warming effect, and why?

at the poles; trees have a lower albedo than the surrounding snow or soil environment and would absorb more solar radiation