Global climate Flashcards
1
Q
Thermosphere
Too much sugar troubles
A
A virtual vacuum, rise in absorbed energy due to energised SW radiation
2
Q
Greenhouse effect
A
Short wave radiation (UV) passes directly through the greenhouse gases, coming from the sun to the earth
Some of this is absorbed by the earth’s surface, and heat is retained
The earth’s surface re-emits some of this radiation as long wave infrared radiation back into the atmosphere
Some of this is again re-radiated back to the earth’s surface
The rest of the long wave passes into the atmosphere.
3
Q
Enhanced greenhouse effect
A
The increasing amount of greenhouse gases in the atmosphere as a result of human activities trap an increasing proportion of long wave radiation from the earth, resulting in more warming
4
Q
Impacts of global warming
A
Migration of animals
Increased sea levels
floods
climate changes - unpredictability
5
Q
Factors affecting insolation
A
Volcanic eruptions Cloud cover Ice-albedo effect Sun spots Earth's orbit Earth's tilt
6
Q
Short wave radiation
A
Energy from the sun that penetrates the atmosphere and reaches the earth’s surface
7
Q
Long wave radiation
A
Radiation that is reflected off the earth’s surface back into the atmosphere
8
Q
Convection
A
transfer of heat by movement of a gas or liquid
9
Q
Global dimming
A
Decrease in intensity of insolation reaching Earth as small droplets reflect more sunlight back into space, preventing sun’s heat getting through to earth’s surface
10
Q
Cause of global dimming
A
Increased presence of aerosol particles in the atmosphere - human action. Aerosols and other particulates absorb solar energy and reflect sunlight back into space. The pollutants can also become nuclei for cloud droplets. Water droplets in clouds coalesce around the particles. Increased pollution causes more particulates and thereby creates clouds consisting of a greater number of smaller droplets. The smaller droplets make clouds more reflective, so that more incoming sunlight is reflected back into space and less reaches the Earth’s surface. This same effect also reflects radiation from below, trapping it in the lower atmosphere (positive feedback).
11
Q
Greenhouse gas
A
Any gas that absorbs and emits radiation in the thermal infrared range. The gases include: Carbon Monoxide, Carbon Dioxide, Methane, Sulphur Dioxide, Nitrous Oxide, water vapour and Ozone
12
Q
Effects of global warming
A
- Sea levels rise, causing flooding in low lying areas e.g: Maldives
- Storm activity will increase due to more atmospheric energy
- agricultural patterns will change e.g: USA’s grain belt will shrink, production decline, but Canada’s growing season will get longer + more productive
- Less rainfall over USA and Northern Europe
- up to 40% of wildlife species’ exctinction
- some areas might get colder, north west Europe if Gulf stream shuts down
- ecosystems damaged, change in biome distribution and species composition e.g: poleward and altitudinal migration
- water shortages - wars over supply
- agriculture - may shift towards poles
- relocation of people living on coast
- increased disease e.g: risk of malaria
13
Q
Possible solutions to GW
A
Renewable energies Hybrid transport Reduce, reuse, recycling of resources Afforestation + Reforestation Carbon sequestration (trapping) International agreements (Kyoto protocol
14
Q
Adaptation
A
Initiatives and measures to reduce vulnerability of human and natural systems to climate change
15
Q
Mitigation
A
Attempts to reduce the causes of climate change
16
Q
Resilience
A
The degree to which people can cope with the impacts of climate change
17
Q
Albedo
A
The amount of incoming solar energy reflected back into the atmosphere by the earth’s surface
18
Q
Anthropogenic
A
human related processes and /or impacts
19
Q
Global warming
A
The increase in temperatures around the world that have been noticed since the 1960s
20
Q
Vulnerability
A
The degree to which a human or natural system is susceptible to the adverse impacts of climate change
21
Q
Mesosphere
A
Temp decreases due to decreasing density preventing absorption of energy
22
Q
Stratosphere
A
Lacks dust and water vapour
stable + thin
increase in temp with height is due to absorption of solar radiation
23
Q
Troposphere
A
most weather processes take place here
fall in temp with height as atmosphere thins
24
Q
Atmospheric energy balance
A
difference between incoming energy and outgoing energy, between insolation and re-radiation.
When it reaches the Earth, some is reflected back to space by clouds, some is absorbed by the atmosphere, and some is absorbed at the Earth’s surface.
The earth-atmosphere energy balance is achieved as the energy received from the Sun balances the energy lost by the Earth back into space. In this way, the Earth maintains a stable average temperature and therefore a stable climate.
25
Atmospheric energy budget
Balance is achieved in three main ways:
Radiation - emission of EM waves
Convection - transfer of heat by the movement of a gas
Conduction - transfer of heat by contact
26
Conduction
transfer of heat by contact
27
Net radiation balance
difference between radiation of energy from the earth and the movement of LWR from particles in the atm
During the day, outgoing long wave radiation is greater than incoming so net loss of energy from earth's surface
28
Greenhouse gases
Water vapour - accounts for 95% of greenhouse gases by volume
Co2 - levels risen from 315 to 400 ppm from 1950 to 2012 - due to human activities
Methane - second largest contributor. Presence in atm increasing by over 1% per year. cattle convert 10% of their food into methane. Natural wetlands and paddy fields are other sources of methane (emit 150 million tonnes per year)
CFCs - synthetic chemicals that destroy ozone as well as absorbing LWR - increasing at a rate of 6% per year and are up to 10,000 times more efficient at trapping heat than CO2
29
Changes in global energy balance
Variations in solar radiation:
- Changes in albedo, as ice melts and is replaced by darker coloured vegetation, amount of insolation absorbed increases causing temp rise
- change in output of energy from sun, 11 year solar cycle and longer periods of changes in the movement of the Earth occur. Variations in Earth's orbit affect seasonal and latitudinal distribution of solar radiation
30
Positive feedback loops (increase in emissions)
Mechanisms:
- melting ice, less reflectivity
- increased Co2 emissions from increased biomass decomposition as more GHG added to atm
- increased forest cover in high latitudes decreasing albedo and increasing warming
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Negative feedback (reduction in emissions)
Burning, leading to more aerosols and less solar radiation at surface, so cooling
Increased evaporation, more cooling, e.g: increased evaporation in tropical and temperature latitudes leading to increased snowfalls in polar areas (happened in Norway)
32
CASE STUDY: Negative feedback in Greenland
- Since 2002, large areas of Greenland ice shelf previously too high and cold to melt have been pouring billions of fresh water into northern atlantic
- greenland's ice sheet max melt area increased by 16% from 1979 to 2002.
- In particular, northern part experienced melting up to an elevation of 2000 metres
- amount of melting ice = rise in sea levels
- also meaning threat of cold winters to britain as melting of greenland ice shut off currents of Gulf Stream
- allowing depressions to dump snow rather than rain on britain thus leading to colder continental rain
- Therefore uncertainty of whether global warming will lead to an increase or decrease in temp over britain
33
Changes to hydrosphere impacts
- sea levels rise, flooding
| - floods can kill 5% of world's pop.
34
Steric effect (Use this term in essay)
Expansion of water as it gets warmer, leading to a slight rise in sea level. It is estimated that sea levels will have risen by 40-80 cm
35
Changes in sea ice
Arctic sea ice declined dramatically since 1975
arctic is believed to be its warmest for 40,000 years and length of melting season increased by nearly 3 weeks since 1979
Not only is volume, thickness and extent declining, time ice remains also changing e,g: in 1988, ice that was more than 4 years old accounted for over 25% of arctic sea ice but by 2013, was less than 1/12th
36
Impacts of sea ice decline
- Methane emissions from Tundra will increase due to release of chlorine atoms fro sea
- wet summers in northern Europe, due to weakened jet stream.
- increased primary productivity in Eastern Bering Sea, due to plankton blooms but melting adversely affected polar bears who have less time to hunt seal pups. Reduce body size + reproductive success
37
Glaciers and ice caps
- they are retreating
- have major impact on region's water supply
- Hindu Kush Himalayan region is the source of many of Asia's major river systems which provide water for drinking, irrigation, industry and more for 1.5 billion people
- studies shown that lower elevations glacial retreat unlikely to cause major water shortages in future due to monsoon water system
- for higher elevation retreat, could alter stream flow characteristics in many basins
- e.g: Gangotri Glacier is one of largest glaciers in Himalayas (30km) long but treated by 76 m from 1996 to 1999
38
CASE STUDY: Retreat of swiss glaciers
- Swiss glaciers predicted to recede at an accelerated rate, causing huge changes in landscape + water balance
- glaciated surface of swiss alps declined from 1800 km2 in 1850 to 1300 km2 in 1971, a loss of 1/3
- surface area decreased from 4.4 to 3.15%
- Gorner Glacier was 15 km long in 1882, but retreated by 26m/yr for few years
- but by 2007 retreat was huge - 290 m
39
Carbon stored in in ice, oceans, biosphere
Prior to the industrial revolution, amount of ice stored on land + in oceans was balanced but human activity has tipped this; carbon sinks have become carbon sources
Most of Earth's carbon stored in rocks but this is unavailable in carbon cycle
This means earth's carbon cycle has been altered, largely as a result of human activity
Before industrial revolution, main changes to carbon cycle were infrequent events e.g: volcanic eruptions, sea floor spreading + meteorites but human activity has moved underground buried carbon to atm
Human activity added 8,0 PgC which oceans absorbed 28% of
40
Carbon in oceans
Carbon content of oceans rising
Increased carbon in atm warms earth + may make plants grow more and store carbon,
On the contrary, carbon in oceans acidifies water, endangering marine life. Since 1750, oceanic pH has dropped by about 0.1, a 30% change in acidity. Some excess carbon dissolves in ocean to become carbonic acid which reacts with carbonate in water to form biocarbonate. Shell building creatures end up with thinner shells e,g: crabs, lobsters
30% of Co2 in atm by humans has diffused into oceans
Also, warmer oceans may decrease the abundance of phytoplankton which grow more vigorously in cool waters
However, Co2 may stimulate growth of certain phytoplankton that can obtain co2 directly from ocean, reducing co2 conc in ocean as they take it up
41
Biosphere
Plants on land absorbed approx 25% of co2 released by humans
some plants grow rapidly with more co2. Estimates suggest that as co2 conc doubles, plant growth increases by 12-76%
Agriculture impacts carbon cycle. When farmland abandoned, e.g: volcano in montserrat erupted, vegetation reverts to forest. However by preventing wildfires, humans prevent carbon from entering the atmosphere and allow carbon to build up in plants
42
Ice
Permafrost contains large deposits of carbon
This low temp reduces rate of decomp of organic plant matter in relation to plant productivity which has allowed large accumulation of carbon to develop in form of dead organic matter
500 Gt stored as dead organic matter
but permafrost beginning to thaw
warming of periglacial environments will lead to increased methane emissions
43
Human impacts of climate change
60 million more africans could be exposed to malaria if world temp rise by 2 deg. Mosquitos would be able to breed in areas previously too cool for them
People forced to flee homes
Hunger + conflict, war over water - more likely to affect LICs than HICs as less tech and economically able to cope
65% of Bangladesh's labour force involved in agriculture, threatened by floods
44
Changes to agriculture
- 35% drop in crop yields across Africa + middle east
- 200 million more people hungry if temp inc by 2 deg
- location of crop growing areas move polewards
- northward shift of wheat growing regions in USA with many unviable by 2050.
- decline in USA's grain belt nut increase in Canada's growing season - affects adversely US economy
- droughts will reduce crop yields so farmers difficult to irrigate
45
Benefits of climate change
- opening up of sea routes as sea ice melts such as Russia's arctic coastline and north west passage connecting atlantic ocean and pacific ocean via arctic ocean
- tourism positively affected as summer seasons may be extended so coastal resorts may develop in more northerly locations. However winter sport holidays e.g: skiiing may stop
- Both Britain and Greece see mortality rates rise by 18 per cent each winter. Especially cold winters cause a rise in heart failures far greater than the rise in deaths during heatwaves.
The increase in average carbon dioxide levels over the past century, from 0.03 per cent to 0.04 per cent of the air, has had a measurable impact on plant growth rates. It is responsible for a startling change in the amount of greenery on the planet. As Dr Ranga Myneni of Boston University has documented, using three decades of satellite data, 31 per cent of the global vegetated area of the planet has become greener and just 3 per cent has become less green. This translates into a 14 per cent increase in productivity of ecosystems and has been observed in all vegetation types.
46
Economic effects of climate change
Costs to recover from natural disasters caused by climate change, for example the current cost of flooding in the UK is $340 million per year and is predicted to rise by approx 430 if temps rise by 2 degrees.
47
UK CASE STUDY
Impacts:
- rising temp - rate of 0.2 deg per decade, high rates of increase in south east esp in summer
- Increased rainfall and wind speeds: annual precip 5% increase by 2020. Winter precip increase everywhere but south more. Gale frequencies will increase by about 30%
- Droughts and floods - dry south east will become drier and moist north west wetter. Expensive to deal with as flooding costs 340 pounds/yr
By 2050, 180,000 homes at risk of flooding
Rising sea levels and higher tides: sea levels will rise at 5cm per decade. By 2050, 35 cm higher causing storm surges and extreme high tides, occuring 20 times more often than now. 20% of coastal defenses vulnerable
Storm surges: deaths, farmland lost, livestock lost
Another storm surge would flood petrochemical complex at Grangemouth which handles 40% of UK's fuel supplies, Recovery cost = 200 billion
48
Positive effects in UK of climate change
- increase of up to 25% by 2050 in timber yields esp in north
- northward shift of farming zones by 200-300 km per deg of warming which will improve some forms of agriculture esp pastoral farming in NW
- Enhanced potential for tourism due to increased temp + reduced precip in summer, esp SE
49
Negative effects in UK
- storms - flooding and erosion in coastal areas
- increase in insects resulting from northward migration and a decrease in number of plant species
- soil drought - soil erosion and shrinkage of clay soils
50
Changes to hydrosphere
- Increase in sea levels due to melting of glaciers AND steric effect - 40cm expected rise
- increased flooding (coastal as well) - could cover 4 million km2 and displace 200 million ppl
- water shortages, leading to wars over water
- increased rainfall
- arctic sea ice decreased dramatically since 1975. Melting season increased to 3 weeks
- by 2013, remaining ice was only 1/12th of original amount
- wave formation increased - 5 metre waves recorded in the Beaufort sea. These waves helped break up sea ice, thus establishing a positive feedback loop of disappearing sea ice and wave formation as under normal conditions sea ice prevents wave formation.
- Negative effect of sea ice decline: Methane emissions in Tundra increase due to release of chlorine atoms from sea
- wet summers in northern europe due to weakened jet stream
- polar bears' size decreased as melting means less time to hunt seals as they have to spend more time on land
- POSITIVES: increased primary productivity in Eastern Bering Sea due to plankton blooms which could take in co2.
HIMALAYAS: water shortages
- Himalayan glaciers retreating
- threat as this region impacts on water supply for 1.5 billion people
- retreat will cause major water shortages in future
51
Changes to carbon in biosphere
- humans added 8 PgC to atmosphere due to fossil fuels and deforestation
- atmospheric carbon content driving changes with carbon content in oceans
- oceans' carbon content is rising
- acidifies water, endangering marine life, 30% of CO@ in atmosphere has diffused into oceans.
- excess CO2 dissolves to form carbonic acid to form bicarbonate - adverse effects on shell building organisms - they are weakened
- also, warmer oceans reduce phytoplankton which grow in cool conditions but co2 may stimulate growth by plants directly absorbing co2 from oceans
- biosphere: plants absorbed approx 25% of CO2 released by humans
- ICE: permafrost contains large amounts of carbon as low temps slow down decomposition. 400-500 Gt
- warming of periglacial envmts lead to more methane emissions
- Biomes: north to south shift in biomes relative to equator
- low lying biomes e.g: mangroves will be lost
- biomes: regions on earth which have certain conditions in which species that are adapted live in
52
Changes to agriculture
- if temps rise by 3 deg, will be 35% in crop yields across Africa and Middle East
- 200 million people could be exposed to hunger
- changes in location of crop growing areas: move polewards e.g: vineyards and wheat
- models predict many wheat growing regions in the USA will become unviable and project a northward shift of wheat growing
- decline in USA's grain belt
- increase in Canada's growing season
- adverse effects of USA's economy
53
Impacts of climate change on people
- 60 million more people malaria infected if temps ^ by 2 deg
- forced to leave homes e.g: residents of low lying islands like Kiribati in South Pacific have left their homes
- POSITIVE: opening up of sea routes as sea ice melts e.g: Russia's Arctic coastline and North West passage connecting Atlantic and Pacific ocean via Arctic ocean but of course, geopolitical issues to be resolved first before international shipping
- tourism could be positively impacted as longer summers and coastal resorts could develop in more northerly locations
- but some winter holiday locations may be stopped due to lack of snow and water
54
Social problems
- Hunger and then conflict
- LICs more affected than HICs as less technologically and economically able to cope as greater % of LIC population vulnerable e.g: 65% labour force involved in agri which is threatened by floods in low lying areas
- Coastal flooding can lead to loss of land, e.g: netherlands, may lead to conflict over resources
- LICs likely to have weak infrastructure, communications and emergency services less able to respond to impacts
55
Extreme weather events
200 million people can be displaced by floods
increase in storm activity
reduced rainfall over USA - drought
4 billion people suffering from water shortages
56
Impacts of temperature increase
1 deg: arctic sea will disappear for good, heatwaves and forest fires, malaria, glaciers providing water supply will disappear, 300,000 people affected by disease
57
difference between carbon sink and a carbon source
```
sink = growing in size and storing carbon
source = shrinking in size and releasing carbon
```
sink examples: oceans, soils, plants
source: forest fires, burning of fossil fuels
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UN framework Convention on Climate Change
Established in 1992
Main objective: stabilize GGG concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system
UNFCCC went into effect in 1994, but failed in its attempt to slow down greenhouse gases
USA did not sign the treaty due to fear of giving China a competitive edge
HICs had to cut their emissions by 20% by 2012 compared to their 1990 emissions.
HICs were encouraged because they have technology
Better able to bear the costs of low-carbon energy developments
Caused a disproportionate amount of historic Co2
LICs need time to develop their economies.
59
Kyoto Protocol
183 countries signed up to stabilize GGG emissions at safe levels that would avoid serious climate change
Aimed to reduce GGG emissions by 5% of their 1990 levels by 2012.
Came into force in 2015
Countries were allocated amounts of co2 they were allowed to emit
These were divided into units and if a country had units to spare, they could sell them to countries that exceeded their unit allowance.
This is carbon trading that occurs in the carbon market.
The Kyoto protocol encourages use of energy sources that do not emit GGG. Avoiding fossil fuels and hydrocarbons and using solar and wind power instead is actively encouraged.
Some countries e.g: France have adopted nuclear power
60
The success of international solutions to climate change depends on...
The extent to which governments wish to sign up to international agreements
Whether governments are preventive or responsive
61
Paris Agreement
2015 UN climate change conference was held in Paris
France had decarbonized its energy production
Over 90% of its energy is generated by nuclear power, hydroelectric power and wind energy
Objective: Limit global warming to 2 degrees compared with pre-industrial levels
Unlike Kyoto Protocol, there are no country specific goals or a timetable for achieving those goals
There is no mechanism to force a country to set a target, nor is there any measure to penalize countries if their targets are not met
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3 key steps of decarbonization:
Energy efficiency:
- achieve a much greater output per unit of energy input. - Much can be saved in heating, cooling and ventilation by appliances.
Reduce emissions of Co2 per MWh of electricity:
This involves increasing amount of energy generated by 0-emission energy e.g: wind and solar or by carbon capture and sequestration to aid this. Use less fossil fuels
Fuel shift:
Electricity generation based on clean primary energy sources. Internal combustion engines in automobiles can be replaced by electric motors. Battery powered vehicles can recharged on a renewable power grid
63
How does agriculture contribute towards emissions
Oxides of nitrogen from fertilisers and methane from livestock are greenhouse gasses.
64
Alternatives to fossil fuels
Photovoltaic cells convert photons into electrical energy
Some of the areas with the highest potential for renewable energy are very distant from centres of population and their source of energy is intermittent. Hence, large scale renewable energy will require the construction of transmission lines
The Desertec project is designed to link North Africa, middle east and europe into a single grid to supply energy for these economies and to export surplus to europe, helping europe solve their deep decarbonization issues
65
Discuss geo-engineering
Use sulphate aerosol particles in the air in order to dim the incoming sunlight and thereby cool the planet to offset the warming effects of CO2.
Place giant mirrors in space to deflect some of the incoming solar radiation
66
Carbon capture and sequestration
Capture co2 before it accumulates in the atmosphere
Capture co2 at site where it is produced and store it underground in a geologic deposit, e.g: abandoned oil reservoir
Allow co2 to enter atmosphere but then use chemical sorbents to attract co2.
67
Disadvantages of carbon capture and sequestration
Cost
Certainty of storing co2 and ensuring it does not leak out
Is there enough room for all this carbon
68
Ocean fertilisation
Fertilise ocean with compounds of iron, nitrogen and phosphorous which introduces nutrients to the upper layer of the oceans, increases marine food production and removes co2.
Triggers algal bloom - photosynthesize
69
Carbon taxing
Burning fossil fuels are taxed in proportion to their carbon content
Those who emit high co2 levels do not pay for the social costs they impose so users of fossil fuels can have "extra carbon tax" equal to the social cost of co2 emitted by the fuel
This would raise the cost of coal, oil and gas compared with wind and solar
70
Carbon trading
Permits are issued by governments to emit co2 which can be traded
Governments set targets for the amount of co2 that industries can emit and plants that exceed co2 limit are forced to buy permits from others who do not need it
71
carbon offsetting
Designed to neutralize effects of the co2 human activities produce by investing in projects that cut emissions elsewhere.
Offset companies buy carbon credits from projects that plant trees or encourage a switch from fossil fuels to renewable energy
They sell credits to individuals and companies that want to go "carbon neutral"
It might be harmful as it dissuades people from changing their behaviour
72
Corporate change mitigation efforts in the USA
In the climate change performance index of 2011, USA placed 54/60 in terms of emission trends
By 2016, it had risen to 34th position
A large number of companies have strategies for climate change which have legislation to reduce greenhouse gas emissions by 80% by 2050.
USA has a large scale wind, solar, biomass and waste from energy sector and industries associated with these sectors are showing an interest and a desire to replace fossil fuels
Companies not associated with these sectors are showing an interest and a desire to replace fossil fuels
However, companies not associated with the renewable energy industry are also attempting to reduce co2 emissions
In 2007, 28 countries formed USCAP, lobbying the government to set legally binding emission targets
In 2008, Levi Strauss, Nike, Starbucks and others formed BICEP trying to reduce emissions to 25% below 1990 levels.
Wants contribution of energy sources to increase to 20% by 2020.
Many US corporations are calling for climate mitigation. Nevertheless, many US companies continue to lobby the government to block such measures, and many US citizens do not want their gvmnt to pursue policies they feel would lead to a decline in US competitiveness and job losses
73
Why is a cloudless night colder ?
There is a large loss of long-wave radiation from the Earth
Because of the lack of clouds, there is very little return of long wave radiation from the atmosphere
Hence, there is a net loss of energy from the surface
74
Give an example of a positive feedback loop
Positive feedback loops - increase in temp:
Melting of polar ice caps results in less ice
Lowers albedo
Since ice is more reflective than water, less ice means less light is reflected and more is absorbed at the earth's surface
This leads to an increase in temperature
Rotting vegetation trapped under permafrost in the tundra releases methane that is unable to escape because of the ice covering
Increases methane levels and temps increase
75
Example of a negative feedback loop
Increased evaporation in low latitudes as a result of higher precipitation may lead to increased snowfall on the polar ice caps, reducing mean global temperature
Burning leads to more aerosols, and thus reduced solar radiation at the surface, causing cooling
76
Bangladesh
Due to its high population density and low resource base, Bangladesh is the most climate vulnerable country in the whole world.
Almost a third of its population, nearly 50 million people, lives in areas which are highly vulnerable to natural disasters such as floods, droughts, cyclones and tidal surges.
Accordingly to the 4th IPCC Report, climate change is likely to make all these hazards more severe and frequent in the future.
In other words, climate change can wipe out years of painstakingly achieved economic gains in a short period and threaten Bangladesh’s aspirations to become a middle-income country in the next 20-25 years.
There are about 10,000 km of embankments, 3500 km of drainage channels, 4,000 regulators and around
2100 cyclone shelters in Bangladesh to provide protection against flood, water logging, salt water intrusion and cyclone.
In addition, major roads and railway tracks have been raised above flood levels and most new real estates are also built above historic flood levels
In addition to the state sponsored interventions, a range of adaptive measures have been developed by the vulnerable communities, often with help from NGOs and extension services of the Government.
For example, growing vegetables on floating platforms and ring-beds, raising plinths of cluster villages (including backyard gardens, tube-wells and latrines), growing salt-tolerant and climate resilient crops, switching to shrimp culture (including organic shrimp) and crab fattening, rearing duck instead of chickens in flood prone areas are all great examples of indigenous adaptations.
Of course, community level adaptations are very location specific and not all can be scaled up all over the country
77
How will climate change affect biomes?
Biomes will move up slopes (altitudinal shift) such as on mountains.
Low lying biomes such as mangroves will be lost
Some organisms will be able to migrate to new areas but they may fail to adapt to the conditions
78
How will climate change reduce biodiversity?
Species change their distribution in response to climate change.
Some species in habitats such as high altitude and latitude places have fewer options for migration and so are more endangered.
Up to 40% of wildlife species could become extinct if temperatures rise by 2%. e.g: Mangroves may be lost
79
Explain the negative feedback loop of periglacial areas
Permafrost contains large amounts of carbon, deposited from dead organic matter.
Low temperature reduces rate of decomposition which allows carbon to accumulate.
Permafrost thaws, releasing methane which can cause global warming as it is a GREENHOUSE GAS
80
Effects of climate change on species?
Carbon dioxide from the atmosphere dissolves in the oceans, and forms carbonic acid, lowering the pH of the water.
This causes the calcium carbonate shells of lobsters to dissolve, making them more vulnerable.
81
Give the predicted effects of climate change if not controlled
A rise in sea levels causes flooding in low lying areas e.g: Bangladesh, could displace up to 200 million people
Floods from melting glaciers could threaten 4 million km2 of land, home to 5% of the world's population
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Effects that rising sea levels could have?
A rise in sea levels causes flooding in low lying areas e.g: Bangladesh, could displace up to 200 million people
Saline intrusion into ground water supplies
Deterioration of coral reefs
Increased coastal erosion
