d4.3 (climate change) Flashcards
characteristics of shortwave radiation
- source, peak wavelength, types of light
emitted from the sun
peaks at wavelength of 400 nm
UV, visible and infrared wavelengths
characteristics of longwave radiation
- source, peak wavelength, types of light
emitted from the earth
peaks at wavelength of 10 000 nm
infrared only (heat)
define the greenhouse effect
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
how much of shortwave radiation from the sun (mostly the UV) is blocked by ozone before reaching the Earth’s surface?
25%
how much of shortwave radiation from the sun reaches Earth’s surface?
75%
how much of the re-emitted longwave radiation is captured by greenhouse gases in the atmosphere?
up to 85%
what are the 4 greenhouse gases (which absorb longwave radiation)?
H₂O, CO₂, CH₄, NOₓ (nitrous oxides)
examples of anthropogenic effects on the climate
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)
how is carbon dioxide removed into the atmosphere?
photosynthesis
how is water vapour removed into the atmosphere?
precipitation
how is water vapour added into the atmosphere?
evaporation & transpiration
most and least abundant greenhouse gases
most: H₂O, CO₂
least: CH₄, NOₓ
how is methane added into the atmosphere? x4
waterlogged habitats
landfills
extraction of fossil fuels
melting polar ice
how are nitrous oxides added into the atmosphere? x3
bacteria in some habitats
agriculture
vehicle exhausts
how does drilling ice for ice cores allow us to determine CO2 levels from that point in earth’s history?
scientists can extract air bubbles from different depths from different times and can determine CO2 levels from that point
define global warming
the long-term increase in Earth’s average surface temperature due to human activities
define albedo
a measure of how much light or radiation is reflected by a surface
define positive feedback
amplifies changes and can drive a system further away from its initial state
define ice-albedo feedback
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
define negative feedback
counteracts changes and helps stabilize the system
define carbon cycle feedback
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
define climate “tipping point”
“climate bombs” with the potential to reinforce global warming through powerful positive-feedback loops
the boreal forest/taiga as a tipping point
characteristics as a carbon store x3
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
how much have emmisions from artic permafrost increased in 5 years?
increased by almost one-third
the boreal forest/taiga as a tipping point
impact of forest fires x1
impact of migration x1
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
define landfast ice
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)
how are emporer penguins harmed by the degredation of landfast ice?
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
how is warming seen in melting ice aside from the increased low albedo of the ocean?
as the ice melts, more land is exposed (low albedo). this absorbs more heat, melting more ice, and causing further warming
where & when does the positive feedback loop of melting ice have a greater effect?
strongest at lower elevations early in the winter and at higher elevations later in the year
warmer arctic temperatures weaken the polar jet stream, what effect does this have?
changing its shape and causing extreme weather further south
define polar jet stream
a circle of fast-moving air currents created by the difference in temperature between the cold Arctic and warmer areas further south
what is upwelling? what benefits does it have?
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
what effect does an influx of warm freshwater onto the ocean surface have?
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
define upslope migration
the tendency for montane (mountain) species to move to higher altitudes
how can growing seasons of trees change with climate change?
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
how can composition changes of forests change with climate change?
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
what ecological impacts can migration of trees have?
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
once CO2 is absorbed by seawater, it reacts with water (H2O) to form what? is this a natural process?
carbonic acid (H2CO3)
this is a natural process, but the increased CO2 levels have amplified it
how are the pH of oceans changed?
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
when do corals lose colour?
when corals expel these algae due to stress, they lose their color and a crucial source of nutrients, further compromising their health
3 approaches to carbon sequestration
afforestation
forest regeneration/reforestation
peat-forming wetlands
look at d4.3 slide 68 on peat-forming wetlands
-
define rewilding
bringing back native species
why may non-native trees be planted in place of native ones during re/afforestation?
some non-native trees will grow more quickly and sequester carbon faster
define phenology
the study of the timing of biological events in relation to climate and environmental changes
examples of life cycle events in plants and animals x3
flowering, migration, or hibernation
define photoperiod
the length of time each day that an organism is exposed to daylight
define bud setting
the developmental stage in plants where buds are formed and prepared for future growth
2 environmental cues for bud setting (explain)
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)
define vernalization
the process by which plants use a prolonged cold period (winter) to promote flowering
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?
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.
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?
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
bivoltine vs monovoltine
bivoltine = producing two broods in a season
monovoltine = producing one brood in a season
how has climate change acted as a selection pressure for tawny owls?
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%)
