ETB: Climate Change Flashcards
define weather
combination of short-term variations in atmospheric conditions at a specific place and time
eg. temp, humidity, precip, wind, clouds
define climate
long-term average weather patterns for diff geog scales (local, regional, global)
mean and variability of relevant quantities
- temperature, precipitation, wind
define climate change
large-scale, long-term shift / change in average weather patterns or average temperatures
statistically significant variation in mean or variability of climate
due to: natural or anthropogenic (human-caused)
define global warming
overall warming of planet, long-term increase in Earth’s average surface temp
due to increased conc of greenhouse gases (CO2 and CH4)
what are the three natural factors that contribute to climate change?
- earth’s changing orbit: changes in tilt of earth (not for modern climate change)
- ocean-atmosphere: el nino (warming) and la nina (cooling)
- volcanic eruptions: sulfur aerosols reflect sunlight, cools planet
state the three key anthropogenic factors of climate change
burning of fossil fuels due to increasing energy usage
deforestation
food choices (increasing meat consumption)
why are fossil fuels burnt, and what are the consequences?
world’s primary energy source
non-renewable, will run out
contribute the most to CO2 emissions, add to greenhouse effect and increases global warming
what is deforestation
permanent clearing of forests to make land available for other uses (eg. agriculture)
by burning or clear cutting
what are the consequences of deforestation?
forests are “carbon sinks”, so upon deforestation
- absorption of CO2 ceases
- carbon stored in trees is released as CO2
what impact do human food choices have on climate change?
more meat: major contributor to climate change
livestock production: 70% of agricultural land use, 30% of land surface of planet
- methane from ruminant (regurgitative digestion) livestock
- nitrous oxide from fertilisers
state the three factors that affect the degree to which any greenhouse gas influences global warming
- concentration in atmosphere
- atmospheric lifetime
- global warming potential
what is the global warming potential of a GHG?
measure of the total energy that a gas absorbs over a particular period of time, relative to CO2 (higher GWP = more warming)
what are the natural processes that release CO2?
- carbon cycle
- respiration in animals, plants, soil bacteria
- forest fires
- volcanic eruption
what is the carbon cycle?
nature’s way of balancing CO2
- exchange btw ocean and atmosphere
- photosynthesis
- stored in fossil fuels, CaCO3
- volcanic eruptions
- carbon sinks
what are carbon sinks (with examples)?
natural systems that absorb and store CO2
atmosphere, ocean, soil, forests
what are the main anthropogenic reasons for increased CO2 emissions?
increase energy usage:
- transportation, industry (cement)
- deforestation (carbon sink removal)
what are the two most important greenhouse gases, and how much of our GHG output do they account for?
CO2: 76%
CH4: 14%
what are the different impacts of CO2 and CH4?
CH4 is x25 more effective than CO2 in warming
CH4 stays in the atmosphere for a shorter period fo time
what are the main anthropogenic reasons for increased CH4 emissions?
livestock farming:
- ruminant digestion (enteric fermentation by microorganisms
- manure of livestock
- flooding paddies for rice cultivation (soil bacteria methanogenesis)
industry: fossil fuels
landfill waste: generated in absence of oxygen
what are the consumption trends of meat?
soaring meat demand with much of the per capita consumption increase from developing countries eg. China, India
what are the different environmental impacts of different types of livestock?
ruminants are the most impactful
- generate methane during enteric fermentation
- require more resources like larger grazing land, fertiliser, energy-intensive feed
generate more manure
define carbon footprint
total amount of GHGs produced to directly and indirectly support human activities
a person’s is sum of all emissions of CO2, induced by one’s activities in a given time frame
how are GHGs emitted during the meat production process?
- livestock production: feed, land, ruminant digestion, manure
- meat processing
- transportation
- wasted food
what is the direct impact of global warming (how much warmer has earth gotten)?
- climate change is real
- current rise of 0.75 degrees C
- if CO2 held constant at double preindustrial values: 2-4.5 degrees C rise
what is sea ice VS ice sheets?
sea ice: frozen salty ocean water
ice sheet: glacier ice covers land, where ice doesn’t melt completely in summer
state the seven impacts of climate change
- melting of polar ice caps
- rising sea levels
- stress on freshwater supplies
- extreme weather events
- death of coral reefs
- migration of fishes and insects
- release of GHG from frozen organic matter
what are the two effects of melting polar ice caps (n two more for sheet ice)?
- accelerated warming from albedo (less white ice and more dark ocean, more heat absorbed)
- severe threats to polar communities
for sheet ice only not sea ice:
- rise in sea level
- loss of freshwater stores
what is albedo?
the proportion of solar radiation reflected back into space by a surface
what are the severe threats to the polar community due to polar ice melting?
- sea ice insulates water, keeping it warm for sea creatures
- breeding and hunting grounds for animals (eg. polar bears)
- releases nutrients when melting, phytoplankton grow (centre of marine food web)
what are the two effects of rising sea levels?
- threat to coastal communities: large urban areas on coastlines, erosion and flooding, coastal wetland loss
- saltwater intrusion: less fresh groundwater to drink
how does climate change stress freshwater supplies?
- global warming causes melting of polar ice caps (97% of freshwater), mixes with sea water
higher temperature increases rate of evap
- dry out some areas, more rain in others
- more precipitation occurs as rain than snow
- more rapid movement from atmosphere back into oceans, unable to store and use it
- increases runoff amount into rivers and lacks, reducing quality of water for use
- freshwater regions threatened (saltwater intrusion, need for desalination)
- less snowpack and earlier snowmelt = less freshwater during summer
what are the two extreme weather events caused by climate change?
heat waves and heavy rains
extreme weather events: more frequent and severe
what are heat waves, and their effects?
- period of days to weeks of very high temperatures
- increasing in frequency, intensity, duration (especially high-humidity)
high humidity and high night-time temperature
- threat for infants and elderly
- damaging to agriculture and livestock, food production impacted
- low humidity: droughts and wildfires
why does climate change cause heavier rain, and what are the effects of it?
temp increase, warmer air, more evap, intense precipitation (not evenly spread)
more runoff into rivers and lakes, decrease water quality, more water-borne disease
what are coral reefs?
marine invertebrates, live in colonies made of many polyps to form colony
excretes CaCO3
where are coral reefs found?
warm, clear, shallow waters with more sunlight
what is the relationship between corals and zooxanthellae?
symbiotic / mutually beneficial
zooxanthellae: give corals food (products of photosynthesis)
corals: give zooxanthellae nutrients and shelter (from UV rays)
what are zooxanthellae?
single-celled, microscopic algae that carry out photosynthesis
what are the two effects of climate change on corals?
- coral bleaching
- zooxanthellae photosynthesis disrupted at higher temps, makes O radicals, corals expel them and expose exoskeletons
- white, weaker corals, die of starvation and disease - ocean acidification affects hard corals
- higher conc of CO2 in air, more dissolves to form carbonic acid, pH falls
- bc Ka and stuff, corals cannot make CaCO3
what is the effect of fish migration due to global warming?
- fish exposed to warmer temps move to cooler waters
- move north or south towards poles, to deeper and cooler water
- ecological: resource competition
- economic: fishermen have less fish
- earlier runoff disrupts migratory behavior and timing of fishes, impeding effective navigation
what is the effect of insect migration due to global warming?
insects are cold-blooded ectotherms
geographic ranges determined by temp
warmer temps = larger ranges of most insect species
poleward migration of many insects
how are monarch butterflies, crop pests, and mosquitos affected due to global warming?
monarch butterflies: without cold trigger, they do not return north to America
crop pests: move to the poles, threatens crops
mosquitos: no longer dying in areas that used to be colder, more insect-borne disease
what is permafrost, and what is its impact due to global warming?
soil is permanently frozen for at least 2 years
stores massive amounts of carbon in the form of frozen organic matter
melting permafrost releases CO2
positive feedback loop: more permafrost melt = more CO2 = more global warming
name the five components of the climate system
atmosphere (air)
hydrosphere (water)
cryosphere (ice)
land surface (land)
biosphere (living things)
what is the troposphere, and where is it?
the troposphere is where weather and climate occur
closest to the ground
define a biome
global-scale biogeographical regions characterised by distinctive climate, soil conditions and dominant species
define biodiversity
number, variety, variability of living
(including diversity within, between species and of ecosystems)
what is an endemic species?
species unique only to a particular place
what is an ecosystem?
biological community and all abiotic factors influencing that community
what is an ecological niche?
total way of life, or role of a species in an ecosystem (includes all environmental factor to grow, survive, reproduce)
describe the tropical rainforest biome
- near equator
- high levels of precipitation
- uniformly high temperature
- large diversity of living things
- food and medicine
describe the artic tundra biome
- far north towards north pole
- cold and dry
- low precipitation, typically snow
- permafrost
what happens to the sunlight that enters earth’s atmosphere?
- 29% reflected by clouds and surfaces
- most absorbed by atmosphere, which are heated
- land and oceans release energy through evaporation, convection
what are greenhouse gases?
absorb and redirect solar energy downwards, keeping heat near earth’s surface
how do greenhouse gases cause global warming?
- more greenhouse gases:
incoming shortwave radiation > outgoing longwave radiation - surface temp increases
what is latitude, and how does temperature vary with it?
measurement of distance north or south of the equator
as latitude increases, temperature decreases
what is altitude, and how does temperature vary with it?
vertical distance above sea level
as altitude increases, temperature gets lower
what two factors determine the type of plant community found at a location?
latitude (temp)
precipitation (rain)
what determines the boundaries of a plant’s distribution, and how does global warming affect this?
minimum temperatures
general warming trends: higher altitude and latitude
name two examples of the increased altitude and latitude of plant species with global warming
altitudinal shift of dominant plant species in Santa Rosa Mountains, SoCal, USA
latitudinal shift of shrubs in northern Alaska, USA
define tolerance (of an organism)
organism’s fitness to cope with an unfavourable environment
define adaptation
genetically determined trait (behavioral, morphological, physiological) that improves organism’s ability to survive and reproduce
what three things does the physiology of plant species refer to?
- nutrition and metabolism
- growth, development, reproduction
- (in response to) environmental
what adaptations of plants to abiotic factors are dependent on each other?
light, temperature, moisture
amt of sun influences photosynthesis and temp
air temp affects humidity, influencing rate of transpiration
in plants, what is the link between temperature and water availability?
higher temp = more water needed (more loss thru transpiration)
less water available = temp rises (less transpiration water loss, but no evap)
what are the three types of plants classified by the availability of water?
hydrophytes: so much water (eg. pond)
mesophytes: some water (eg. grass in soil)
xerophytes: no water (eg. desert)
what are the four adaptations by plants in the face of water stress?
- smaller leaf size and shape to reduce diffusion shell
- curl (reduce SA) / wilt (lack of turgor)
- turn yellow earlier / shed (reduce transpiration)
- carbon allocation: more to roots less to leaves (more water intake less water outtake)
what are C3 plants?
first stable compound formed during Calvin cycle is 3-carbon phosphoglycerate (PGA)
light energy capture + CO2 to sugars: only in mesophyll cells
define a C4 plant
first stable compound formed during Calvin cycle is 4-carbon oxaloacetate (OAA)
light energy capture + CO2 to sugar: mesophyll and bundle sheath cells
what is the adaptive advantage of the C4 pathway in plants?
higher photosynthetic rate = greater water use efficiency (CO2 uptake / H2O loss)
what are examples of C4 plants?
grasses native to tropical and subtropical regions, shrubs in arid and saline environments
what does stress mean (in relation to organisms)?
any environmental change that acts to reduce the fitness of organisms
what are the trends for surface temperature due to global warming?
- +0.75 degrees C
- rate of warming is increasing
- changes not equally distributed
- arctic warming twice as quickly
- winter months warm more
- max-min temp var has decreased (min temp rising faster than max temp)
what are the trends for precipitation due to global warming?
not spatially or temporally uniform
- high latitudes (at the poles) increase by 0.5%, mainly in autumn and winter
- tropics less precipitation by 0.3%
what are the four types of organisms, based on their body temperatures?
endotherms: warm-blooded, heat-producing
OR
ectotherms: cold-blooded, adaptive techniques
AND
homeotherms: tightly control body temp (homeostasis)
OR
poikilotherms: cannot tightly control body temp
how do the size of endothermic animals change in response to increased temperatures?
they maintain constant body temps
increasing temp = decreasing size (more energetically efficient)
what is phenology (with some examples)
the timing of seasonal activities of plants and animals (eg. termination of dormancy, onset of reproductive activity, migratory behaviour)
what are the effects of climate change on food chains (+ caribou example)?
production of offspring no longer coincides with annual peak of resource availability (eg. plants for herbivores)
- caribous do not reproduce when plants grow
- caribous use changes in day length to decide when to reproduce (unchanged)
- plants grow by temp (increased)
- calf mortality increased
what is the effect of climate change on niche occupation (+ foxes example)?
increasing fitness of one species at expense of the other
- arctic region warms, tundra replaced by boreal forest
- interspecific competition btw arctic and red fox
through competition and predator-prey relationships
state the five ways in which rising temperatures influence insects
- extended geographical ranges
- increased overwintering success (less death)
- increased population growth
- changed synchrony in pest-host relations (host plants stressed, more vulnerable)
- increased insect migration
what are the three types of biodiversity?
- species:
- no of diff species
- diff in number of each species - genetic
- variation in DNA composition btw indivs of a species (the more the better) - ecosystem:
- number and variety of ecosystems
- diversity of habitats
what are the effects of climate change on genetic diversity?
- droughts increase stress on populations
- warmer temperatures force organisms to move higher in latitude and altitude
- population size falls (some members perish) = less genetic diversity
what are the effects of climate change on species diversity?
- influence “web of interactions” btw species
- mismatch btw plant and pollinator populations, extinction of both
- reduction of amt and availability of habitats, extinction
state the two main consequences of loss of biodiversity due to climate change
- loss of biomedicines
- loss of food security
what are named examples of plant and animal biomedicines, and a lost opportunity?
- plant: rosy periwinkle for Hodgkin’s disease and leukemia
- animal: marine sponge for HIV-AIDS
- loss: gastric brooding frogs for stomach ulcers
how does climate change lead to a loss of food security?
- some may have better fitness and grow better as food = biological insurance
- reservoirs of genetic diversity, allows for phenotypic plasticity
- mostly in tropics, under greatest threat by climate change
what are the four dimensions of food security?
- availability
- accessibility
- utilisation (quality and safety)
- stability (access over time)
what are direct examples of climate change affecting crops (mean temp, precipitation, extreme weather events)
mean temp: reduced food production in tropical regions
- reduced rice yields
increase in frequency, duration, intensity of droughts
- water stress and more fire hazard
- soil moisture falls, less crops produced
changes in rain and snow:
- larger variation: seasonal flow scarcities
more extreme weather events
- crop destruction (eg. cyclones)
what are the three indirect impacts of climate change on crops?
- pest attack
- larger geographical spread of insects
- pests do better w more CO2 and temp - competition from weeds
- they thrive under heat, more rain, more CO2 - crop pathogens and diseases
- eg. aflatoxicose outbreaks in kenya
what are the four effects of climate change on livestock?
- heat stress, animals less productive
- less feed crops
- animals less healthy bc more vectors and pathogens
- less biodiversity
example: bluetongue disease in europe
what are the effects of climate change on fisheries and aquaculture?
- most aquatic animals are ectotherms
- rising temps influence reproductive cycles
eg. malawi, africa inland fisheries: less reproduction - reduction of available O2 reduces max body weight
fishes migrating polewards, large-scale redistribution of global marine fish catch potential
what is dengue, and its three forms?
viral infection transmitted by bite of infected female Aedes mosquito
dengue fever, dengue hemorrhagic fever, dengue shock syndrome (the worst)
what is viremia?
medical condition where virus is present in the blood
what is the life cycle of the dengue mosquito?
- egg
- larva
- pupa
- adult
what are the four main factors of susceptibility of a human to dengue?
immune status, genetic status, age of host, virus strain
describe the genome and structure of DEV (dengue virus), and its four serotypes
three structural proteins encoding:
- nucleocapside (C)
- membrane-associated protein (M)
- envelope protein (E)
+ seven non-structural proteins
enveloped, spherical
four serotypes: DENV-1/2/3/4
what is the effect of global warming on dengue mosquitos?
- warmer and wetter
- expansion of geographical range, mosq activity, frequency of bites, vector survival
- higher altitudes and latitudes
- more rain = good for egg-laying
