Text D Energy 11.3 Biomes Change Naturally

Question 1

What was Alberta once classified as in terms of its biome?

Answer 1

A dense, tropical rain forest

This historical classification indicates significant climate changes over time.

Question 2

What does a journey to the Canadian Arctic represent in terms of Earth’s history?

Answer 2

A journey back in time

The Arctic reflects conditions that were present in much of Canada after the last ice age.

Question 3

How does Earth’s climate behave over long periods?

Answer 3

It remains fairly consistent

However, it experiences fluctuations over geological timescales.

Question 4

What evidence do geological and fossil records provide about past climates?

Answer 4

They show dramatic changes in climate

Fossils of tropical plants and animals indicate warmer past climates.

Question 5

What significant geological events have occurred within the past two million years?

Answer 5

Glaciers covered large parts of Earth’s surface

These events are known as ice ages.

Question 6

What are interglacial periods?

Answer 6

Warm periods that alternate with ice ages

They last for varying lengths of time, such as 60,000 to 12,000 years.

Question 7

What do ice cores drilled in Greenland reveal about climate history?

Answer 7

They show rapid changes between cold and warm spells

Some cold spells lasted over 1000 years.

Question 8

When did the current interglacial period begin?

Answer 8

About 11,500 years ago

This marks the end of the last ice age.

Question 9

What is paleoclimatology?

Answer 9

The study of past climates

It helps scientists make predictions about future climates.

Question 10

How can a change in lake levels indicate past climatic conditions?

Answer 10

It reveals the balance between rainfall and evaporation

This is one method used in paleoclimatology.

Question 11

What kind of information can be obtained from glacier ice air bubbles?

Answer 11

Data about past atmospheric conditions

These air bubbles act as time capsules.

Question 12

What did the Geological Survey of Canada reconstruct about Canada’s paleoclimate?

Answer 12

Vegetation zones from 6000 years ago

This reconstruction used pollen, plant fossils, and lake sediments.

Question 13

What climatic changes did scientists find when comparing conditions from 6000 years ago to today?

Answer 13

Vegetation zones moved northward, increased fires, and a declining water table

These changes indicate a shift in climate across Canada.

Question 14

How much did the average annual temperature change throughout Canada?

Answer 14

Increased by one to two degrees

This change occurred except in British Columbia, Yukon, and the high Arctic islands.

Question 15

What is the ‘snowball theory’ related to Earth’s climate?

Answer 15

The hypothesis that Earth was once covered in ice for about 10 million years

It suggests carbon dioxide played a role in melting the ice.

Question 16

What is the current tilt of Earth on its axis?

Answer 16

23.5°

Earth’s tilt has fluctuated between 22.3° and 24.5° in the past.

Question 17

How does Earth’s tilt affect solar radiation?

Answer 17

The tilt affects the amount of solar radiation received, with maximum tilt resulting in warmer regions farther from the equator and minimum tilt leading to colder climates.

When the tilt is at its maximum, the poles receive more solar radiation.

Question 18

What is the shape of Earth’s orbit and its fluctuation period?

Answer 18

The shape of Earth’s orbit fluctuates over periods of about 100,000 years.

Sometimes the orbit is almost a perfect circle, and other times it has an oval shape.

Question 19

What theory explains the movement of continents?

Answer 19

Continental Drift

This theory states that all landforms sit on tectonic plates that float on the Earth’s liquid core.

Question 20

What was the name of the supercontinent that existed about 225 million years ago?

Answer 20

Pangaea

The name Pangaea comes from the Greek word meaning ‘all lands.’

Question 21

What evidence supports the theory of continental drift?

Answer 21

Similar fossils of plants and animals found on the east coast of Brazil and the west coast of Africa.

This suggests that these continents were once attached.

Question 22

What are the potential causes of natural climate change?

Answer 22

Possible causes include:
* Earth’s tilt
* Earth’s orbit
* Continental drift

Scientists have suggested several possibilities but cannot fully explain natural climate change.

Question 23

True or False: Earth’s tilt has a direct impact on climate patterns.

Answer 23

True

The amount of solar radiation received at different locations depends on the tilt of Earth.

Question 24

Fill in the blank: The tilt of Earth affects the climate by changing the amount of solar radiation received at different __________.

Answer 24

[locations]

This is influenced by the angle of Earth’s tilt.

Question 25

What happens to the climate when Earth's tilt is at its minimum?

Answer 25

The poles receive less solar radiation, resulting in a colder climate for regions farther from the equator. ## Footnote This contrasts with periods of maximum tilt, which warm these regions.

Question 26

What affects the transfer of thermal energy on Earth's surface?

Answer 26

The slow movement of the continents and the opening and closing of ocean basins ## Footnote This transfer affects wind and precipitation patterns, which can change climates over time.

Question 27

How can the movement of tectonic plates explain climate change?

Answer 27

It could explain some of the evidence for climate change over the last several million years ## Footnote If continents moved from one latitude to another, the climate would certainly change.

Question 28

What is the process that breaks down rocks into smaller pieces?

Answer 28

Weathering ## Footnote Weathering involves both physical and chemical processes.

Question 29

What usually involves carbonic acid in the weathering process?

Answer 29

Chemical weathering ## Footnote This acid is formed when carbon dioxide gas reacts with water vapor in the atmosphere.

Question 30

What does chemical weathering use up from the atmosphere?

Answer 30

Atmospheric carbon dioxide ## Footnote The reaction produces calcium carbonate.

Question 31

What happens to the material transported by erosion?

Answer 31

It is transported to oceans and lakes ## Footnote Some of the calcium carbonate is used to build the skeletons of phytoplankton.

Question 32

What catastrophic events can cause significant atmospheric changes?

Answer 32

Large meteor or asteroid collisions and major volcanic eruptions ## Footnote These events can put enormous volumes of dust, ash, and smoke into the atmosphere.

Question 33

What effect can a cloud of soot, dust, or smog have on sunlight?

Answer 33

It can reflect or absorb sunlight, preventing it from reaching Earth's surface ## Footnote This would significantly slow down photosynthesis in plants and algae.

Question 34

What might a sudden reduction of plant material cause in animal species?

Answer 34

Starvation for many animal species ## Footnote Such an event could lead to mass extinction, including that of the dinosaurs.

Question 35

What might cause the climate to warm up after a catastrophic event?

Answer 35

Increase in carbon dioxide and other greenhouse gases ## Footnote This warming could occur alongside the cooling effect of reduced sunlight.

Question 36

Fill in the blank: The lithosphere plays a role in removing excess _______ from the atmosphere.

Answer 36

carbon dioxide ## Footnote Weathering is a key process in this removal.

Question 37

What evidence suggests a large meteorite struck Earth about 65 million years ago?

Answer 37

A crater in the Yucatan peninsula ## Footnote This event is linked to the extinction of the dinosaurs.

Question 38

What are the natural greenhouse gases mentioned in the text?

Answer 38

* Carbon dioxide * Water vapour

Question 39

What is a negative feedback loop in the context of climate change?

Answer 39

A situation where warming triggers conditions that lead to cooling ## Footnote Example: Increased cloud cover reflecting solar radiation.

Question 40

How does increased evaporation of water affect global temperatures?

Answer 40

It leads to increased cloud cover, which reflects solar radiation back into space.

Question 41

What is a positive feedback loop related to Earth's temperature?

Answer 41

A situation where cooling leads to conditions that cause further cooling ## Footnote Example: Increased sea ice reflects more solar radiation.

Question 42

What role do clouds play in climate feedback mechanisms?

Answer 42

They can reflect incoming solar radiation, leading to cooling.

Question 43

Fill in the blank: Increased cloud cover due to global warming can eventually lead to _______.

Answer 43

global cooling

Question 44

What happens to solar radiation when there is an increase in sea ice?

Answer 44

More solar radiation is reflected back into space.

Question 45

True or False: Increased carbon dioxide in the atmosphere always leads to global warming.

Answer 45

False ## Footnote It can also lead to feedback mechanisms that result in cooling.

Question 46

What climatic changes can result from feedbacks to climate change?

Answer 46

* Changes in cloud cover * Changes in the extent of glaciers * Changes in carbon dioxide concentration

Question 47

What is the impact of increased global temperatures on cloud formation?

Answer 47

It increases the evaporation of water, leading to more cloud formation.

Question 48

What can a drop in Earth's temperature result in?

Answer 48

The formation of sea ice.

Question 49

Fill in the blank: A drop in Earth's temperature results in increased _______ of solar radiation.

Answer 49

reflection

Question 50

What are mass extinction events?

Answer 50

Periods during which many species are wiped out.

Question 51

What percentage of species died during the largest mass extinction 245 million years ago?

Answer 51

About 80 percent.

Question 52

What significant event occurred 208 million years ago?

Answer 52

The beginning of the age of dinosaurs.

Question 53

How did the mass extinction 208 million years ago affect early reptiles?

Answer 53

It may have removed competition and ensured their success.

Question 54

Which mass extinction is most famous?

Answer 54

The extinction of the dinosaurs.

Question 55

How long ago did the extinction of the dinosaurs occur?

Answer 55

About 65 million years ago.

Question 56

What dramatic changes are mass extinctions often associated with?

Answer 56

Relatively dramatic changes in climate.

Question 57

What hypothesis do scientists have regarding asteroid collisions and mass extinctions?

Answer 57

They filled Earth's atmosphere with dust particles.

Question 58

What is the survival likelihood of species during rapid climate changes?

Answer 58

Species that are best adapted to new conditions are most likely to survive.

Question 59

What usually happens to organisms during quick climate changes?

Answer 59

They often die before they have a chance to adapt.

Question 60

What scenarios can longer-term climate changes cause?

Answer 60

* Animal migrations * Evolution of physical characteristics * Changes in diet * Decrease in population * Forests moving north or south

Question 61

What does the red outline in Figure 11.38 represent?

Answer 61

The boreal forest 6000 years ago.

Question 62

What stimulated the northward movement of the boreal forest?

Answer 62

A long-term increase in temperature.

Question 63

What evidence helped scientists determine forest fire frequencies?

Answer 63

The amounts of charcoal in samples of pollen and plant fossils.