Question 1

In what ways might climate change benefit the planet?

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Question 2

Discuss the significance of a predicted increase in global temperatures of 3°C, as opposed to a predicted increase of 1°C.

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Question 3

In association with other natural factors, the Milankovitch cycles explain the advance and retreat of glaciers according to which of the following time periods?

Accepted Answer

The Milankovitch cycles explain the advance and retreat of glaciers over the time period of ten thousand years to one hundred thousand years, in association with other natural factors.

Question 4

In which of the following periods did the Viking colony in Greenland perish?

Accepted Answer

The Viking colony in Greenland perished during the Little Ice Age, a cold period that lasted from the 16th to the mid-19th century. The harsh conditions made it difficult for the Viking settlers to survive, and the colony eventually disappeared around the 15th century.

Question 5

What percentage of the Earth's surface does ice presently cover?

Accepted Answer

Ice currently covers about 10% of the Earth's surface, primarily in the polar ice caps and glaciers.

Question 6

What are some of the possible consequences of climate change?

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Question 7

Ice cores provide a record of which of the following?

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Question 8

In a warmer world, which of the following changes will likely happen to the growing season at higher latitudes?

Accepted Answer

In a warmer world, the growing season at higher latitudes is likely to be longer due to the earlier snowmelt, longer thawing periods, and warmer temperatures. This will allow plants to grow and mature for a longer period of time.

Question 9

Which of the following accurately compares CO2 levels during cold glacial periods and warm interglacial periods?

Accepted Answer

During cold glacial periods, it's known that CO2 levels were lower than during warm interglacial periods. This is due to the fact that during cold periods, much of the Earth's water was frozen in glaciers, so less CO2 was able to be absorbed by the oceans, leading to lower atmospheric CO2 levels. In contrast, during warm interglacial periods, the oceans warmed and were able to absorb more CO2, leading to higher atmospheric CO2 levels.

Question 10

Discuss the changes that occur in the Earth's orbit and the orientation of the Earth in its orbit. Over what time scales do these different changes occur?

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Question 11

What is meant by the term positive feedback? What role could positive feedback play in the atmospheric greenhouse effect? Would this enhance or reduce global warming? What is an example of a "negative feedback" mechanism?

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Question 12

Asia and the North American continent have been connected by a land bridge at various times during the past. When was the Bering land bridge most recently exposed? Did this coincide with a warm or cool climatic period?

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Question 13

Which of the following defines a positive feedback mechanism?

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Question 14

Carbon dioxide concentrations in the atmosphere have been increasing steadily since the beginning of the industrial revolution and may double by the middle of the next century. Why is this of concern?

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Question 15

Which of the following refers to the precession of the equinox?

Accepted Answer

The precession of the equinox refers to the slow wobble of the Earth on its axis, which gradually shifts the position of the equinoxes and solstices over a cycle of approximately 26,000 years.

Question 16

In addition to carbon dioxide, what other gases may contribute to the problem of global warming? Why might global warming lead to an increase in global cloudiness? What possible effects would an increase in cloudiness have on global warming?

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Question 17

Which of the following reasons for climatic change is proposed by the Milankovitch theory?

Accepted Answer

The Milankovitch theory proposes that variations in the Earth's orbit as it travels through space cause climatic changes.

Question 18

Everything else being equal, which of the following will most likely result from a gradual increase in global CO2?

Accepted Answer

CO2 is a greenhouse gas, which means it traps heat in the atmosphere. A gradual increase in global CO2 would lead to an increase in surface air temperature as the heat is trapped and the greenhouse effect intensifies.

Question 19

If the Earth was in a cooling trend, which of the following processes would most likely act as a positive feedback mechanism?

Accepted Answer

Increasing the snow cover around the Earth would act as a positive feedback mechanism in a cooling trend because snow and ice have high albedo, meaning they reflect a significant portion of the sunlight back into space. This reflection reduces the amount of solar energy absorbed by the Earth, leading to further cooling and thus more snow and ice formation, reinforcing the cooling trend.

Question 20

Which of the following statements applies to the biogeophysical feedback mechanism that occurs in the Sahel?

Accepted Answer

Reduced vegetation in the Sahel leads to a decrease in surface temperatures and rainfall. This is because vegetation plays a crucial role in the local climate by providing shade (which cools the surface) and through transpiration, which adds moisture to the air, potentially increasing rainfall. When vegetation is reduced, less moisture is added to the air, leading to decreased rainfall. Additionally, with less shade, the surface can become cooler.

Quiz 17: Earths Changing Climate