d4.3 (climate change)

Question 1

characteristics of shortwave radiation
- source, peak wavelength, types of light

Answer 1

emitted from the sun

peaks at wavelength of 400 nm

UV, visible and infrared wavelengths

Question 2

characteristics of longwave radiation
- source, peak wavelength, types of light

Answer 2

emitted from the earth

peaks at wavelength of 10 000 nm

infrared only (heat)

Question 3

define the greenhouse effect

Answer 3

the process by which radiation from a planet’s atmosphere warms the planet’s surface to a temperature above what it would be without its atmosphere

Question 4

how much of shortwave radiation from the sun (mostly the UV) is blocked by ozone before reaching the Earth’s surface?

Answer 4

25%

Question 5

how much of shortwave radiation from the sun reaches Earth’s surface?

Answer 5

75%

Question 6

how much of the re-emitted longwave radiation is captured by greenhouse gases in the atmosphere?

Answer 6

up to 85%

Question 7

what are the 4 greenhouse gases (which absorb longwave radiation)?

Answer 7

H₂O, CO₂, CH₄, NOₓ (nitrous oxides)

Question 8

examples of anthropogenic effects on the climate

Answer 8

population growth (too many people using limited resources)

over consumption (industrialized societies are using more resources per person from our planet than people from poor nations)

advancing technologies (introducing technology w/o knowing how it will influence the environment)

direct harvesting (large losses of rainforest and its biodiversity)

pollution

atmospheric change (burning of fossil fuels and depletion of our ozone layer)

endangered species (destruction of their habitats)

Question 9

how is carbon dioxide removed into the atmosphere?

Answer 9

photosynthesis

Question 10

how is water vapour removed into the atmosphere?

Answer 10

precipitation

Question 11

how is water vapour added into the atmosphere?

Answer 11

evaporation & transpiration

Question 12

most and least abundant greenhouse gases

Answer 12

most: H₂O, CO₂
least: CH₄, NOₓ

Question 13

how is methane added into the atmosphere? x4

Answer 13

waterlogged habitats
landfills
extraction of fossil fuels
melting polar ice

Question 14

how are nitrous oxides added into the atmosphere? x3

Answer 14

bacteria in some habitats
agriculture
vehicle exhausts

Question 15

how does drilling ice for ice cores allow us to determine CO2 levels from that point in earth’s history?

Answer 15

scientists can extract air bubbles from different depths from different times and can determine CO2 levels from that point

Question 16

define global warming

Answer 16

the long-term increase in Earth’s average surface temperature due to human activities

Question 17

define albedo

Answer 17

a measure of how much light or radiation is reflected by a surface

Question 18

define positive feedback

Answer 18

amplifies changes and can drive a system further away from its initial state

Question 19

define ice-albedo feedback

Answer 19

as global temperatures rise, ice and snow melt, reducing the earth’s albedo (since ice reflects more sunlight than open water)

lower albedo means more sunlight is absorbed by the earth’s surface, which leads to further warming and more ice melt

Question 20

define negative feedback

Answer 20

counteracts changes and helps stabilize the system

Question 21

define carbon cycle feedback

Answer 21

plants may grow more vigorously with higher CO2 levels, potentially increasing the amount of carbon sequestered from the atmosphere.

warmer temperatures could stimulate soil microbes to decompose organic matter more quickly, which might temporarily enhance plant growth due to nutrient release

Question 22

define climate “tipping point”

Answer 22

“climate bombs” with the potential to reinforce global warming through powerful positive-feedback loops

Question 23

the boreal forest/taiga as a tipping point

characteristics as a carbon store x3

Answer 23

perhaps thebiggest terrestrial carbon store in the world

about95% of carbon in boreal forestis stored in its soil, unlike tropical forests where most is stored in the trees above ground

athird of the band of boreal is embedded with permafrost lands, which is seeing extreme melting

Question 24

how much have emmisions from artic permafrost increased in 5 years?

Answer 24

increased by almost one-third

Question 25

the boreal forest/taiga as a tipping point

impact of forest fires x1
impact of migration x1

Answer 25

as the boreal belt warms, fires and insects will stress the forests even further in a positive carbon feedback loop

they continue to migrate north to continue growth in their ideal environment, but they can only go so far north and thus become very vulnerable

Question 26

define landfast ice

Answer 26

an essential component of the coastal sea ice system (acts as a floating extension of the land (almost like a belt), landfast ice is the most accessible form of sea ice and the one most often encountered by people)

Question 27

how are emporer penguins harmed by the degredation of landfast ice?

Answer 27

emperor penguins have a unique approach to raising a family that requires stable ice, which only landfast ice can provide

reduced ice extent, increased fragmentation and earlier breakup can lead to population declines of this iconic species

Question 28

how is warming seen in melting ice aside from the increased low albedo of the ocean?

Answer 28

as the ice melts, more land is exposed (low albedo). this absorbs more heat, melting more ice, and causing further warming

Question 29

where & when does the positive feedback loop of melting ice have a greater effect?

Answer 29

strongest at lower elevations early in the winter and at higher elevations later in the year

Question 30

warmer arctic temperatures weaken the polar jet stream, what effect does this have?

Answer 30

changing its shape and causing extreme weather further south

Question 31

define polar jet stream

Answer 31

a circle of fast-moving air currents created by the difference in temperature between the cold Arctic and warmer areas further south

Question 32

what is upwelling? what benefits does it have?

Answer 32

the movement of warmer water from hydrothermal sea vents to the surface

upwelling brings up cold, nutrient-rich waters to the surface, which encourage seaweed growth and support blooms of phytoplankton

Question 33

what effect does an influx of warm freshwater onto the ocean surface have?

Answer 33

further blocking the formation of sea ice and disrupt the sinking of denser cold, salty water

this could slow or even stop the ocean conveyor belt, which would result in global climate changes that could include drastic decreases in Europe’s temperatures due to a disruption of the Gulf Stream

Question 34

define upslope migration

Answer 34

the tendency for montane (mountain) species to move to higher altitudes

Question 35

how can growing seasons of trees change with climate change?

Answer 35

temperatures can extend the growing season in cooler areas, making them more hospitable for species that previously couldn’t survive there. this allows trees to establish new populations in these previously inhospitable regions

Question 36

how can composition changes of forests change with climate change?

Answer 36

as different species move into new areas, the composition of forests changes. some species may thrive in new conditions, while others may struggle or become extinct if they cannot migrate or adapt quickly enough

Question 37

what ecological impacts can migration of trees have?

Answer 37

can have cascading effects on ecosystems. For instance, it can alter habitat availability for wildlife, affect soil composition, and change interactions between different plant and animal species

Question 38

once CO2 is absorbed by seawater, it reacts with water (H2O) to form what? is this a natural process?

Answer 38

carbonic acid (H2CO3)

this is a natural process, but the increased CO2 levels have amplified it

Question 39

how are the pH of oceans changed?

Answer 39

Carbonic acid quickly dissociates into bicarbonate (HCO3-) and hydrogen ions (H+). The increase in hydrogen ions leads to a lower pH in seawater, making it more acidic

Question 40

when do corals lose colour?

Answer 40

when corals expel these algae due to stress, they lose their color and a crucial source of nutrients, further compromising their health

Question 41

3 approaches to carbon sequestration

Answer 41

afforestation
forest regeneration/reforestation
peat-forming wetlands

Question 42

look at d4.3 slide 68 on peat-forming wetlands

Answer 42

-

Question 43

define rewilding

Answer 43

bringing back native species

Question 44

why may non-native trees be planted in place of native ones during re/afforestation?

Answer 44

some non-native trees will grow more quickly and sequester carbon faster

Question 45

define phenology

Answer 45

the study of the timing of biological events in relation to climate and environmental changes

Question 46

examples of life cycle events in plants and animals x3

Answer 46

flowering, migration, or hibernation

Question 47

define photoperiod

Answer 47

the length of time each day that an organism is exposed to daylight

Question 48

define bud setting

Answer 48

the developmental stage in plants where buds are formed and prepared for future growth

Question 49

2 environmental cues for bud setting (explain)

Answer 49

photoperiod: changes in light duration can trigger bud setting in many plants (some plants require shorter days or longer nights to initiate bud formation and prepare for flowering or dormancy)

temperature: temperature fluctuations can also influence bud setting (any plants require a period of cold temperatures (vernalization) to set buds properly and ensure flowering in the spring)

Question 50

define vernalization

Answer 50

the process by which plants use a prolonged cold period (winter) to promote flowering

Question 51

1 species examples who uses photoperiod as a significant part of their life cycle (how do they use it?)

AND

1 species examples who uses bud setting as a significant part of their life cycle (how do they use it?)

what is the relation between these two?

how may tropic mismatch occur? what are its impacts?

Answer 51

migrating reindeer
= live in northern latitudes (greenland, norway). use day length (photoperiod) to know when to return to breeding ground

mouse-eared chickweed
= relies on temperature to come out of dormancy (recall bud setting).

the chickweed is a food source for the reindeer, therefore the return of chickweed and the reindeer needs to be aligned to ensure the reindeer population can survive

when synchrony is disrupted (EG not enough chickweed), there is not enough energy in the trophic level the chickweed occupies (producer), resulting in not enough nutrition for the reindeer to survive.

Question 52

how does climate change increases to number of insect lifecycles per year? (in the case of the spruce bark beetle) how are spruce trees impacted?

what benefit do the beetles provide to their ecosystem?

Answer 52

when the eggs hatch, the larvae feed on the wood under the bark. leads to structural damage and death to tree.

warmer temperatures due to climate change seeing increase in number of spruce pine beetles due to shift to bivoltine (producing two broods in a season) cycle.

beetles tend to attack trees already in poor health. they play an important ecological role in killing off unhealthy trees. clears canopies for healthy trees to receive more sunlight

Question 53

bivoltine vs monovoltine

Answer 53

bivoltine = producing two broods in a season
monovoltine = producing one brood in a season

Question 54

how has climate change acted as a selection pressure for tawny owls?

Answer 54

with reduced snow depth, brown tawny owls are no longer as strongly selected against and their winter survival has increased (less snow so brown owls are able to camoflouage better year round) (30% to 50%)