Lecture iv - Effects of Climate Change Flashcards
1
Q
Greenhouse Gases … since 1900s. Why?
A
Increased
- due to increased human activities esp. during the Industrial Revolution that sees much rapid development in many countries
2
Q
Classify effects of climate change
A
- Range of impacts
-primary vs secondary
- environ/climatic
- social (qlty of life)
- econ
- political (govnance) - Spacial scale of impact
- global
- regional
- national
- local/community
- DCs vs LDCs (variat n) - temporal scale of impact
- short vs long term
3
Q
Summarise effects of contemporary climate change
A
- more ENSO & its impacts (intensif n of natural disaster eg hurricane, drought)
- melting polar ice caps, glaciers, rising sea lvl
- impact on ecosystem
- spread infectious disease eg malaria, dengue
- opening of northern Sea route
- impact on food product n
- increased natural disasters & associated impacts (social, econ, environ)
4
Q
Explain climatic changes as effect of climate change
A
- global warm can hv sig impact on climate
=> greater extremities in temp & rainfall
=> hydrological impacts eg flood, drought (extreme climatic events) - global warm cld lead to increase in MORE extreme ENSO events (& cause ocean-atmos circulat n change & impacts)
5
Q
Describe how climate change affects ENSO
A
- In 1982-83, brought most serious condit n ever seen, caused $8 billion damage (econ impact) & 1000 ppl dead (social impact)
- areas w usual high precipitat n will now experience droughts eg SEA, India
- heavy intense rainfall might cause floodings eg Peru, S. America
- INCREASED FREQUENCY
El Nino usually occur every 7 yrs but recently, due to enhanced ghg effect, time period for this phenomena is shortened to 3-4 yrs - INCREASED MAGNITUDE (scale of event)
impacts of El Nino r now more severe as extreme climatic conditions become more destructive
6
Q
Explain how climate change affects marine ecosystems
A
- more frequent increase in sea surface temp (SST) can hv detrimental effects on marine ecosystem
Eg bleaching of coral reefs first recognised on Pacific coast of Panama following 1982-83 El Nino event
1997-98 El Nino event is strongest to date, causing unprecedented coral bleaching, death worldwide (and expected to intensify, occur more frequently and prolonged, endangering future survival of coral reefs) - Coral bleaching threatens all organisms that depend on reef:
- (Social impact) Species use corals as habitat and food (fish, mammoth whale shark, endangered salt water crocodile) => disrupt food chain, food supply
- (econ impact) Local communities depend on reef for food, income, & tourist biz => takeaway livelihood of local fishermen
- weaker reef, mean less shoreline protection from storms and erosion
- Other impacts of coral bleaching r; loss of coral islands, decline in species diversity & changes in the overall reef communities
7
Q
Explain how global warming affects hurricanes
A
- more ghg gas trapped in atmos, higher SST
=> more occurence (frequent) of cat 4, cat 5 (mag) hurricanes due to stronger thermal reservoir - more intense vortex can b generated
Evidence: - cat 5 hurricane Mitch along coast of Honduras (America) is strongest storm in 1998, w 250km/h winds (cause torrential rainfall, widespread flood, landslide)
- > = 11 000 killed, 9000 missing + econ damage USD$2 billion
UN estimates 25 mill environ refugees were created in 1990s, forced fr their homes by natural disasters exacerbated, caused by CC
8
Q
Explain how global warming affects heat waves
A
- heat wave occur when high Pa systems strengthen, remain over region
- high Pa system fr air sinking cause little, no convect n, inhibit form n of rain, prevent heat fr rising
=> trap heat, cause heat waves - more ghg gas oso trap radiating heat => increased temp
9
Q
Explain impact (DIVA hand) of climate change on polar ice caps, glaciers and sea levels
A
- increased temp can lead to melt of ice caps, glaciers
=> sea lvl rise - rising by 1.7mm/yr over last century, abt 10-15cm over past century
–> due to global warm, it cld rise by as much as 1m by 2100
=> detrimental effects: - inundate deltas (physical impact), reducing amt arable land for agri & livelihood (socio-econ impact)
- Tourism: some biz can b affected eg skiing industry can go out of biz bcos increase in snow melt (econ impact)
10
Q
Explain impact of climate change on aquatic and terrestrial ecosystems in terms of distribution
A
- change in distribut n of flora & fauna - general shift to diff latitude
=> species that can oni grow/thrive within specific temp range must migrate to diff latitude or die-off due to global warm
eg many fish species move northwards, search for cooler waters. Cod fishes move polewards in Atlantic Ocean - research show as earth heats up, climate zone shift outwards fr equator
=> countries north of equator eg UK find themselves living in recognisable climate of countries far closer to equator, as will southern countries eg New Zealand - within our lifetime, London may hv climate of Southern France, while scorching deserts of northern Africa may creep into Europe
eg CC cld drive 1/4 of land animals, plants into extinct n, w >1 mill species lost by 2050
11
Q
Explain how climate change affects spread of infectious diseases
A
- CC promote ideal condit n for breeding
- climate related events eg flooding/rain create spawning pools for mosquitos to breed/spawn
- diseases/disease carriers thrive in hotter, wetter temp
=> spread of diseases into non-tropical areas eg malaria, zika, dengue
=> 60 % of world projected to be in malaria zone by 2100
eg in 1997-98 El Nino, heavy rainfall, flood in North Eastern Kenya caused many ideal mosquito spawning pool=> fr jan to may 1998, there was major epidemic of falciparum malaria, in a pop n w/o immunity (first outbreak since 1952) - compounded widespread food shortages, nurse strike and late recognit n caused severe public health problem
12
Q
Explain how climate change creates Northern Sea route
A
- melt Arctic Ice open Northwest Passage in summber
- until 2008, Arctic-pack ice prevented regular marine shipping thruout most of year
- change in pack ice (Arctic shrinkage) rendered waterways more navigable
- offer alternatives for shipping routes btw europe & asia
- as ice melts, range of activities increase
eg shipping, oil & gas explorat n, tourism (all cld bcome more accessible as ice recedes) - warming can oso create new border disputes as countries increase their military presence in Arctic
eg btw Russia, US, Norway,etc. - if part of Arctic bcome ice-free, new sea routes can open up which may disrupt economies of some cities/countries eg Singapore (where 7% of its GDP rely on maritime industry)
13
Q
Explain how climate change affects food production
A
- increase in temp can affect precipitat n & soil moisture across regions in world, leads to major shifts in agri
- particularly devastating on countries engaging in primary product n as impt econ sector
–> crops tend grow faster in warmer condit n (but oso depend on yield condit n)
POSITIVE IMPACTS:
- gradual greening or northern latitude fr 1980 onwards
- grow season increased by 11 days on avg since early 1960s, increasing crop yields in Europe
NEGATIVE IMPACTS:
- high probability grow season temp in tropics & sub-tropics bcome more extreme, too hot to grow certain type crops by end of 21st century
14
Q
Explain how climate change affects natural disaster frequency
A
- Increase in natural disaster
- Floods: brought abt by hurricanes or increased rainfall
eg Mississipi flood, 2008 - Droughts: increased temp due to ENSO or other factors
=> detrimental impacts on agri, irrigat n, hydroelectric power schemes
eg in 2008 Mississippi Floods caused dams and levees to be breached across parts of Wisconsin, Iowa and Indiana along Mississippi river
eg in 1997-98 ENSO related drought event for 6 months experienced in Brazil, caused insuff rainfall during rainy season, decrease grain product n drastically, caused 4.8 mill ppl risk starvat n
=> create environ refugees
15
Q
explain how climate change affects coastal areas
A
- low-lying coastal areas more prone to flood due to rise sea lvl
–> can b further caused, even aggravated by human activity or natural disaster
eg
IPCC predict sea lvl cld rise as much as 1m by 2100
-> inundate deltas and coastal regions
up to 9% Bangladesh, 15% Nile valley and Delta cld b flooded, reducing amt arable land available
some 8 mill ppl in Egypt cld b homeless, and even DCs cities like London, LA, Miami, Maldives, SG r threatened - issues stemming fr geographical locat n cnt b altered but can b mitigated thru HARD and/or SOFT engineering methods
