Lecture vi - Impacts of Contemporary Climate Change on Ecosystems Flashcards
Define ecosystem
a dynamic complex of plant, animal & micro-organism communities & non-living environ interacting as a functional unit
Define and describe aquatic ecosystem
- community of living organisms (aquatic life) interacting w water-based environ as functional unit
- play crucial roles in:
1. maintain biodiversity by support various life form, provide habitat, so contributing to eco balance
2. provide essential svcs to humans, eg water purificat n, fisheries, rcs, recreational opportun - sensitive to environ changes, so can b affected by pollut n, habitat destruct n, CC, & other human activities
Define and describe terrestrial ecosystem
- community of living organisms interacting w LAND-based environ as functional unit
- see interact n of both biotic (plants, animals) & abiotic (temp, precipitat n, soil, etc.) components
- play crucial role in
-> maintain biodiversity by support all life form on land, provide habitat
-> regulate climate
-> regulate nutrient cycling
-> offer valuable rcs eg food, wood, medicinal plants for human, & recreational, aesthetic values - can b impacted by human activities eg deforestat n, urban n, agri practices, cause habitat destruct n, loss biodiversity, change in eco dynamics
=> impt to conserve, sustain health, balance of terrestrial eco
Describe contemporary climate change
- increase in global temp (global warm) due to enhanced gh effect, largely drive by human activities eg burn FF, deforestat n
How does contemporary climate change affect temperature and precipitation?
- more ice melt at higher latitude in N. Atlantic ocean
- add more freshwater into ocean
- less saline, warm water slow down or stop THC
=> regional cooling of W. Europe, Eastern N. America
=> drier condit n w little or no precipitat n - increased evaporat n in tropics eg Amazon rainforest
- more water vapour in atmos
- promote cloud form n
=> increased rainfall - increased temp in arid areas eg Sahara desert
- lack moisture in environ
=> more severe, prolonged dry condit n w little, no precipitat n
What are the general impacts of contemporary climate change?
- increased intensity, frequency extreme weather event eg El Nino, hurricanes, cause flooding, drought, etc.
- change in seasonal patterns
=> alter timing, distribut n precipitat n thruout yr, change onset, durat n of wet, dry season => significant impact on water availability for eco, humans - droughts and changes in hydrological cycles
=> change frequency, severity droughts in certain regions
=> influence timing, amt water available in rivers, lakes, groundwater
=> affect agri, industry, human consumpt n
Explain increased intensity and frequency of extreme weather events like El Nino phenomena
- El Nino S. Oscillat n (ENSO) is recurring climate pattern exhibiting irregular variat n in wind, sea surface temp over central, eastern tropical Pacific Ocean
ENSO oscillate in 3 stage: - neutral phase (aka Walker Circulat n), operate under normal climatic condit n
- Warm phase (El Nino), characterised by warmer global temp
- Cool phase (La Nina), characterised by cooler temp
–> both El Nino, La Nina usually occur btw 5-7 yr but due to CC, shortened; El Nino now occur MORE frequently every 3-4 yr, more intense
=> more severe droughts at W. Pacific Ocean eg Indonesia, Australia
=> much heavier rainfall in other place towards E. Pacific Ocean eg Peru, Ecuador in S. America
=> change in intensity tropical cyclone
Explain influence of El Nino on Western Pacific Ocean
- cause increased temp, reduced rainfall
immediate impacts:
- intensify heat wave, severity of bushfires
- E. & N. Australia likely experience much warmer, drier condit n w minimal rainfall, increase risk of extreme heatwave, drought, fire danger (opposite is true during La Nina)
Explain impact of contemporary climate change on terrestrial ecosystems (Australia)
(E. & N. part Australia likely experience warmer, drier condit n mimimal rainfall, increase extreme heat wave, drought, forest fire)
terrestrial impacts:
- severe drought/intensify heat wave - lack water supply for growth, loss forest life
- uncontrolled spread forest fire - destruct n habitat, biodiversity (eco imbalance)
forests destroyed affect water cycle (tree take in water fr soil, release thru leaves by transpirat n, moisten air, cause cloud form n & rain); w/o tree, dry air, low humid, precipitat n cause drought-prone, desert like climate
affect man by:
- (social) loss forest life deprive suff food supply, valuable rcs eg medicine, aesthetic value
- (social) heat wave can cause water shortage, man dehydrat n/ heat stroke esp in LDCs (potable water scarcity)
- (socio-econ) forest fire cause casualty, loss lives, destroy home, property, loss agri, tourism revenue
Explain impacts of contemporary climate change on aquatic ecosystems (Australia)
(E. & N. part Australia likely experience warmer, drier condit n mimimal rainfall, increase extreme heat wave, drought, forest fire)
Impact on aquatic eco
- loss biodiversity
warm sea water lack oxygen, higher temp accelerate rate evaporat n, cause increase salinity so fish species must expend more energy avoid excess water loss, cause growth, reproduct n problem
- coral reef degradat n, bleaching
loss breeding grd/habitat for many species eg dolphins, whales
- rapid, excess growth harmful algal blooms of diatoms
more saline ocean water favourable growth condit n of algal blooms, which release harmful toxins that can kill some organisms, deplete oxygen in water
impact on man
- (econ) coral bleach, reef degrad n can cause much econ loss to coastal communities, associated marine industries
eg Great Barrier Reef Australia contribute $6.4 billlion to econ in tourism, marine activities
- (social) man lose impt food, medicine rcs
eg cardiovascular diseases, ulcers, leukemia can b treated w chemical cpd fr organisms in reefs
> half new cancer drug research focus on marine organisms mostly on coral reef
loss of fish being rich protein source
- (environ/social) man will suffer more fr intensify effect global warm when natural C sink eg coral reef die off, promote +ve feedback mechanism fr acid n ocean water
=> more rapid warming, extreme warmer events for man
Explain influence of El Nino on Eastern Pacific Ocean
- during el nino event eg 2023-24, much stronger warm appear along west coast S. America, last several month, often accompanied by heavy rainfall in arid coastal region Ecuador, N. Peru
=> coastal flood, inundated land by rising water of river, soil eros n causing landslide in Ecuador, N. Peru
Explain impact on terrestrial ecosystem of contemporary climate change (Ecuador, N. Peru)
(El Nino bring much rain to Ecuador, N. Peru)
Impact on terrestrial eco
- high rainfall cause intense flood, soil eros n, cause landslide (wash away impt nutrient for plant, animal growth, uproot tree)
=> destroy habitat, life, loss biodiversity, eco imbalance
impact on man:
- (social) landslide can cause casualty, loss lives
- (socio-econ) landslide destroy homes, properties, infra eg roads, electricity, water pipes (entail high socio-econ costs, inconvenience, disrupt n to econ activities, high restorat n cost)
- (econ) loss revenue fr agri as crops die fr waterlogging condit n, loss forests decrease food supply, valuable rcs eg medicine, aesthetic value
Explain impacts of contemporary climate change on aquatic ecosystems (Peru)
(El Nino bring much rain, warmer wetter condit n => more intense flood )
impact on aq eco
- loss aq biodiversity
water off coast Peru warmer than usual, so no upwell cold water => lesser phytoplankton survive => fewer aq life eg anchovies, other species part of food chain can survive since less phytoplankton to eat
due to dilut n, increased freshwater input fr heavier rainfall cause less saline environ
- shortage freshwater for consumpt n by terrestrial anima species eg freshwater turtle as contaminat n water supply by seawater during floods
impact on man
- (econ) econ loss to coastal communities in fishing industry (subsistence, commercial)
eg anchovies swim deeper into ocean, harder to reach for fishing vessels
- (socio-econ) diminish biodiversity can srsly affect socio-econ livelihood of nearly half world pop n (3.3 billion) depending on fish for protein (~ 60 million ppl working in fisheries, agri sector world wide for fishing industry will b negatively affected w depleting aq biodiversity)
Explain impacts of contemporary climate change on tropical cyclone intensity
- tropical cyclone (aka hurricanes over N. Atlantic ocean, cyclone over Indian ocean, typhoon over Pacific ocean) r intense storm, come fr warm tropical sea producing torrential rain, sustained winds >= 119km/h
- rise sea surface temp can contribute to intensify tropical cyclone
=> more intense, destructive rainfall associated w these storms - major threat to human life, property, econ activites due to:
-> high velocity wind
-> heavy rainfall (cause storm surge, coastal flood)
-> land inundat n w rising water
-> eros n
