D4.3 Climate Change

Question 1

Climate

Answer 1

A long-term average of the weather (over 20-30 years), not year-to-year variations

Question 2

Climate change

Answer 2

A long-term change in global or regional climate patterns, caused by natural or human factors, such as increased levels of atmospheric carbon dioxide produced by the use of fossil fuels

Question 3

Greenhouse effect

Answer 3

the heating caused by the atmosphere on Earth’s surface because certain atmospheric gases absorb and emit infrared radiation

Question 4

Greenhouse gas

Answer 4

A gas that contributes to the greenhouse effect by absorbing infrared radiation

Question 5

Global warming

Answer 5

an increase in the global average temperature of the Earth’s surface and
atmosphere

Question 6

Albedo

Answer 6

The fraction of solar radiation reflected by a surface or object, often expressed as a percentage

Question 7

Landfast ice

Answer 7

sea ice that is ‘fastened’ (attached) to the coastline, to the sea floor along shoals or grounded icebergs.

Question 8

Upwelling

Answer 8

process where deep, cold water rises toward the surface of the ocean

Question 9

Upslope range shift

Answer 9

process where montane species move higher up the mountains in response to recent temperature increases

Question 10

Afforestation

Answer 10

the establishment of forests in an area where there was no previous tree cover
(NOT reforestation)

Question 11

Carbon sequestration

Answer 11

The capture and storage of carbon dioxide from the atmosphere by physical or biological processes such as photosynthesis

Question 12

Photoperiod

Answer 12

the period of time each day during which an organism receives light i.e. day lengths

Question 13

Life cycle

Answer 13

The series of changes in the life of an organism, including reproduction

Question 15

How does climate change and landfast ice melting affect emperor penguins and its breeding sites?

Answer 15

These birds breed on Arctic sea ice, laying and incubating their eggs, and raising their young.
The early melting of sea ice is not giving them enough time to raise their young.

Question 16

How does the melting of landfast ice and the subsequent loss of habitat affect the walruses in the arctic?

Answer 16

These mammals rely on Arctic sea ice, where mothers can alternate periods of feeding their young and hunting for food in the ocean nearby
The early loss of ice means that nursing mothers need to care for their young further from the water’s edge, leaving young without protection for longer periods when the mothers hunt for food

Question 17

What factors are ocean currents driven by?

Answer 17

wind, temperature, and salinity gradients

Question 19

What is anthropogenic climate change?

Answer 19

Anthropogenic climate change is the warming of the atmosphere that is caused by human activities.

Question 20

What are greenhouse gases?

Answer 20

Greenhouse gases are gases that absorb radiation re-emitted from the earth’s surface, trapping it in the atmosphere and contributing to the greenhouse effect.

Question 21

True or False?

Carbon dioxide and methane are examples of greenhouse gases.

Answer 21

True.

Carbon dioxide and methane are both greenhouse gases that contribute to the greenhouse effect.

Question 22

What human activities have caused an increase in atmospheric carbon dioxide?

Answer 22

Human activities that contribute to increased carbon dioxide levels are:

burning fossil fuels
deforestation
peat bog destruction

Question 23

What human activities have caused an increase in atmospheric methane?

Answer 23

Human activities that contribute to increased atmospheric methane include:

farming cattle
disposing of waste in landfill sites
extraction of fossil fuels from underground
growing rice in paddy fields

Question 24

True or False?

There is not enough evidence to show that increased atmospheric carbon dioxide and increased global temperatures are causally linked.

Answer 24

False.

There is enough evidence to show that increased atmospheric carbon dioxide and increased global temperatures are causally linked.

Question 25

What is positive feedback?

Answer 25

Positive feedback is a mechanism that leads to increased change away from a normal state.

Question 26

Why is global warming an example of a positive feedback cycle?

Answer 26

Global warming is an example of a positive feedback cycle because global warming causes changes that lead to more global warming.

Question 27

True or False? Melting polar ice caps increase Earth's overall albedo.

Answer 27

False. Melting polar ice caps decrease Earth's albedo, leading to more absorption of solar energy.

Question 28

How do wildfires contribute to the positive feedback cycle of global warming?

Answer 28

Wildfires contribute to the positive feedback cycle of global warming as follows: atmospheric carbon dioxide is increased during wildfires due to combustion of plant material and reduced photosynthesis global warming increases wildfires become more likely to to higher temperatures

Question 29

True or False? Peat bogs always release carbon dioxide.

Answer 29

False. Peat bogs only release carbon dioxide when decomposition increases due to warming. When stable they function as carbon sinks.

Question 30

What is the connection between increased activity of microorganisms and increased global warming?

Answer 30

The connection between increased activity of microorganisms and increased global warming is as follows: increased decomposition in peat bogs and permafrost releases carbon dioxide as temperatures increase increased activity of methanogenic microorganisms releases methane as permafrost melts

Question 31

True or False? Boreal forests always act as carbon sinks.

Answer 31

False. Boreal forests can switch from being carbon sinks to carbon sources; this tipping point occurs due to the effects of global warming.

Question 32

What is the primary cause of reduced water availability in boreal forests that occurs due to global warming?

Answer 32

The primary cause of reduced water availability in boreal forests due to global warming is reduced snowfall due to increased temperatures; this reduces the water available from snow melt.

Question 33

Define the term forest browning.

Answer 33

Forest browning is the process during which trees lose their green pigment and turn brown due to drought caused by global warming.

Question 34

What is legacy carbon combustion?

Answer 34

Legacy carbon combustion is the release of carbon that has been locked up for many years in living trees, dead needles on the ground, and within the soil itself, typically through forest fires.

Question 35

How does global warming affect Emperor penguins?

Answer 35

Global warming affects emperor penguins by causing earlier melting of sea ice; this reduces the time that Emperor penguins have to raise their young on the Antarctic sea ice where they breed.

Question 36

How does early loss of Arctic sea ice affect Walruses?

Answer 36

The early loss of Arctic sea ice forces walrus mothers to care for their young further from the water's edge, leaving young without protection for longer periods when the mothers hunt for food.

Question 37

How do changes in ocean currents due to global warming affect energy flow through food chains?

Answer 37

Changes to ocean currents due to global warming can prevent normal nutrient upwellings from the deep ocean. This reduces primary production and means that less energy is available to marine food chains.

Question 38

How has global warming affected montane bird species in New Guinea?

Answer 38

Global warming has caused many bird species in the mountains of New Guinea to migrate to higher altitudes; this is an upslope range shift.

Question 39

How has global warming affected North American tree species?

Answer 39

Global warming has caused range contraction and northward, or poleward, range shifts in North American tree species.

Question 40

What is ocean acidification?

Answer 40

Ocean acidification is the process by which ocean pH decreases. This occurs when there is an increased in dissolved carbon dioxide, leading to an increase in H+ ions.

Question 41

How does ocean acidification affect coral reefs?

Answer 41

Ocean acidification can weaken and dissolve the calcium carbonate exoskeletons of corals and reduce the availability of carbonate ions needed for building these structures.

Question 42

True or False? Ocean acidification is a direct result of global warming.

Answer 42

False. While ocean acidification and global warming share the same cause (increased atmospheric carbon dioxide), ocean acidification is not a direct result of global warming.

Question 43

What is coral bleaching?

Answer 43

Coral bleaching occurs when coral polyps expel their algae symbionts due to high water temperatures, causing reefs to lose their bright colours.

Question 44

How does coral bleaching affect a coral reef?

Answer 44

Coral bleaching can result in death of coral polyps and the collapse of reef ecosystems.

Question 45

Define the term carbon sequestration.

Answer 45

Carbon sequestration is the process of capturing and storing carbon dioxide from the atmosphere.

Question 46

What is the difference between reforestation and afforestation?

Answer 46

Reforestation involves planting trees in deforested areas while afforestation is the creation of new forests on lands that have not been recently forested.

Question 47

How can peat bogs be restored?

Answer 47

Peat bogs can be restored by: filling in drainage ditches to restore peat to its waterlogged state reducing the harvesting of peat to allow recovery

Question 48

What are the two tree-planting approaches to carbon sequestration that are debated by scientists? (NOS)

Answer 48

The two approaches to carbon sequestration debated by scientists are: planting non-native tree species that grow quickly and sequester carbon rapidly rewilding with native species; this sequesters carbon more slowly but may benefit biodiversity

Question 49

What is phenology?

Answer 49

Phenology is the study of the timing of biological events.

Question 50

What are some environmental factors that can influence the timing of biological events?

Answer 50

Environmental factors that can influence the timing of biological events include: photoperiod (day length) temperature

Question 51

True or False? Time of flowering can be influenced by photoperiod.

Answer 51

True. The timing of plant flowering can be influenced by day length.

Question 52

True or False? A bird species will always build their nests on exactly the same date each year.

Answer 52

False. Birds may not always build their nest on the same date each year. The timing of nesting will be determined by factors such as temperature and food availability.

Question 53

How is climate change affecting the synchrony of biological events in migrating reindeer populations?

Answer 53

Climate change is causing a phenological mismatch between migrating reindeer and the growth of their food plant, Arctic mouse-ear chickweed. Reindeer migration timing is determined by day length, while the growth of Arctic mouse-ear chickweed is determined by temperature This means that migration timing is unaffected by climate change, but the growth of Arctic mouse-ear chickweed is, resulting in low food availability for reindeer during their breeding season

Question 54

How is climate change affecting the life cycle of the spruce bark beetle?

Answer 54

Global warming has increased the number of life cycles completed by the spruce bark beetle each year; higher temperatures mean that two life cycles are more likely to occur. This increases the size of the beetle population and therefore increases their impact on tree growth.

Question 55

How has climate change affected the fitness of colour variants in tawny owls?

Answer 55

Climate change has resulted in an increase in fitness for the brown tawny owl variant. It is thought that a reduction in snow cover provides brown owls with a reproductive advantage over pale-coloured owls due to increased camouflage.