Carbon - EQ1 - Flashcards
1
Q
What is carbon
A
- a common element on earth
- it exists in gas, liquid & solid forms
- in both biotics & abiotic forms
2
Q
In the carbon cycle, the exchange of carbon is between _ main stores
A
4
3
Q
What are the 4 main stores in the carbon cycle
A
- biosphere - plants & animals
- lithosphere - rocks & sediments
- hydrosphere - oceans
- atmosphere - the air
4
Q
Like in the (1), there is (2) amount of carbon on earth
A
- hydrological cycle
- only a certain
5
Q
What are the 3 forms of carbon
A
- inorganic (found in rock)
- organic (found in plant material)
- gaseous (CO2, CH4)
6
Q
Carbon cycle - Fluxes
stores ____ in size
A
vary
7
Q
What is a carbon flux
A
- the process of transferring the carbon between these reservoirs
8
Q
What do fluxes usually involve
A
- a biogeochemical reaction (photosynthesis, respiration, decomposition & combustion)
9
Q
What can fluxes be measured in
A
Pg - Petagrams
GT - Gigatons
(both equal 1 billion tonnes)
10
Q
What are the different timescales of carbon fluxes
A
- seconds to minutes
- annual
- 10-500 years
- millions of years
11
Q
Give an example of a carbon flux on a time scale of seconds to minutes
A
- plants absorb carbon through photosynthesis then transpire this back into the atmosphere
12
Q
Give an example of a carbon flux on a time scale of annual
A
- seasonal variations in the biosphere (e.g autumn leaves)
13
Q
Give an example of a carbon flux on a time scale of 10-500 years
A
- carbon from dead plant material can be incorporated into soils,
- where it may stay for years, decades or centuries,
- before being broken down by soil microbes, & released back into the atmosphere
14
Q
Give an example of a carbon flux on a time scale of millions of years
A
- organic matter that becomes buried in deep sediments & protected from decay
- was slowly transformed into deposits of coal, oil & natural gas, the fossil fuels we use today
- when we burn these substances once again to the atmosphere in the form of CO2
15
Q
What is the scientific view of how old the earth is
A
4.6 billion years old
16
Q
When did dinosaurs exist
A
- The Mesozoic period,
- in the Triassic & Jurassic eras
17
Q
When did humans first evolve
A
- 300,000 to 400,000 years ago
18
Q
What are Cyanobacteria & Stromatolites
A
- Primitive bacteria, which started photosynthesising, adding oxygen to the atmosphere & absorbing CO2
- This happened un the Cambrian era & this evolutionary step enabled life as we know it to evolve
19
Q
Why is the carboniferous period so significant
A
- From 360 mya to about 300 mya, in the middle of this period, the carboniferous rainforest collapsed, resulting in the depostion of many coal beds
20
Q
Where does the word ‘Carboniferous’ come from
A
- The latin word, ‘carbo’, meaning coal
- Carboniferous means coal-bearing
21
Q
The global carbon cycle, one of the major…………. cycles, can be divided into….
A
- biogeochemical
- geological & biological compounds
22
Q
Describe the ‘Geological carbon cycle’
A
- Slowest reservoir turnover rate - at least 100,000 years
- The rate carbon enters & leaves is very slow
- Carbon is stored in rocks/sediment & only leaves through volcanic emissions or through chemical weathering of rocks
23
Q
Describe the ‘Biological carbon cycle’
A
- Faster reservoir turnover rate
- Carbon is not sequestered for long & flows between oceans, atmosphere & vegetation
24
Q
Define sequestering
A
- the natural storage of carbon by physical or biological processes, such as photosynthesis
25
Explain the 'Geological Carbon Cycle'
1. Volcano
* Terrestrial carbon, held within the mantle, is released into the atmosphere as carbon dioxide when volcanoes erupt
* This is known as 'outgassing'
26
Explain the 'Geological Carbon Cycle'
2. rainfall
* CO2 within the atmosphere combines with rainfall
* to produce a weak acid (carbonic acid aka acid rain)
* that dissolves carbon-rich rocks, releasing bicarbonates
27
Explain the 'Geological Carbon Cycle'
3. Rivers
* Rivers transport weathered carbon & calcium sediments to the ocean, where they are deposited, aswell as subaerial porcesses at the coastline contributing carbonates to the ocean.
28
Explain the 'Geological Carbon Cycle'
4. organisms
* This carbon found in shells & skeletons from animals, and organic matter from plants
* then sinks to the seabed when animals and plants die.
* Calcium ions combine with bicarbonate ions to form calcium carbonate
* which precipiates and forms calcite sediment,
* overtime this lithifies is and converted to limestone through decomposition and cementation.
29
Explain the 'Geological Carbon Cycle'
5. tectonics
* Carbon-rich rocks are subducted along plate boundaries & eventually emerge again when volcanoes erupt
30
Explain the 'Geological Carbon Cycle'
6. metamorphism
* The presence of intense heating along subduction plate boundaries, metamorphose (or alters) sedimentary rocks by baking, creating metamorphic rocks
* CO2 is released by the metamorphism of rocks rich in carbonates during this process
31
In the carbo cycle there is a natural...
balance between carbon production & absorption within the cycle
32
In the carbo cycle there can be occassional ........... e.g...
* disruptions
* major volcanic eruptions emit large quantities of carbon into the atmosphere
33
What is the impact of volacnic eruptions in the atmosphere
* extra CO2 sent into the atmosphere
* which leads to rising temperatures, increased evaporation & higher levels of atmospheric moisture
* this increases aci rain & therefore chemical weathering which slowly rebalances the cycle
34
Most of the earth's carbon is .............
geological
35
Most of the earth's carbon is geological, & results from:
* the formation of sedimentary carbonate rocks in the ocean
* carbon derived from plants & animlas in shale, coal & other rocks
36
In the oceans today, ....% of carbon-containing rock is from....
* 80%
* shell-building (calcifying) organisims e.g corals & plankton
37
How does the fromation of sedimentary rock form th earth's carbon
-limestone
* After organisms die, they sink to the sea floor
* Overtime layers of shells sediment are cemented together & lithified (turned to rock), storing the carbon in stone - limestone & its derivatives
38
Define calcifying
* to make someting hard, especially by the addition of substances containing calcium
39
How is shale a geological store of carbon
* The remaining 20% of rocks contain organic carbon from organisms that have been embedded into layers of mud
* Over millenia, heat & pressure compresses the mud & carbon, forming sedimentary rock like shale
40
How is coal a geological store of carbon
* fossil fuels were made up to 300 million years ago from the remains of organic material
* organisms once dead, sank to the bottom of rivers & seas, & were covered in silt & sand & then started to decay anaerobically
41
How is coal a geological store of carbon
-Anaerobic decay operates over ........
* millenia
42
How is coal a geological store of carbon
-what are the products of anaerobic decay
methane and carbon dioxide
43
How is coal a geological store of carbon
-the deeper the deposit, the more...
heat & pressure is exterted on the deposits
44
Define soil respiration
* a measure of carbon dioxide (CO2) released from the soil from decomposition of soil organic matter (SOM) by soil microbes
45
Define respiration
* a process in living organisms involving the production of energy, typically with the intake of oxygen & release of CO2
46
Define photosynthesis
* the process by which green plants & some other organisms use sunlight to synthesize nutrients from carbon dioxide & water
47
Define diffusion
* the process by which CO2 interacts with the ocean, either being released or absorbed
48
Define sinking
* descend from a higher to a lower position; drop downwards
49
Define decomposition
* process by which dead organic susbtances are broken down into simpler organic or inorganic matter such as carbon dioxide
50
Define rock cycle
* the basic concept in geology that describes transitions through geological time among the three main rock type: sedimentary, igneous & metamorphic
51
Molecules of CO2 enter the ocean by...
* dissolving into the ssea surface waters via diffusion
52
The amount of CO2 that diffuses & dissolves in the sea surface water depends on...
variables such as wind, sea surface mixing, concentration of CO2 & the temperature of the water
53
Once dissolved in surface seawate, how can CO2 enter into the ocean carbon cycle
* Through 3 different mechanisms:
* the physical carbon pump
* the biological carbon pump
* the carbonate pump
54
# Thermohaline Circulation
What is a conveyor
* warm currents tends to be at the surface & cold currents tend to be deep in ocean currents travelling back along the bottom of the ocean
55
# Thermohaline Circulation
Why is an oceanic converyor important
* it balances the climate, responsible for moving carbon & also heat
56
what is the thermohaline circulation
* the planets interconnected conveyorbelt of sea wtaer driven by differences in temperature (thermo) & salinity (haline)
* which also powers the physical carbon pump
* and moving carbon in the carbonat epump from the surface to deeper waters
57
Themohaline circulation only happens because of...
* brine rejection --> if we turn this off, all ocean currents will cease to exist
58
What is brine
* really salty water
59
Where does brine rejection take place
* really cold parts of the world, around Greenalnd, near the Artic Ocean
60
Summarise what takes place in brine rejection
* It is the process that occurs when salty water freezes,
* the salts do not fit in the crystal structure of water ice,
* so the salt stays in the water beneath the ice
61
# The Physical Carbon Pump Process
1. warm surface waters
- tropical water takes up heat & remains relatively salty
- these warm salty currents travel near the surface,
- towards higher latitiudes,
- carrying both heat & dissolved CO2
62
# The Physical Carbon Pump Process
2. high lat cooling, co2 uptake & brine reject
* cold water absorbs more CO2, therefore as the equatorial waters move towrads the poles more CO2 is absorbed
* when sea ice forms, the salts do not fit in the crustal ice stucture of these,
* so the salt staus in the water bneath the ice, in a process known as brine rejection
* this increases the waters density
63
# The Physical Carbon Pump Process
3. downwelling
* this combined cooling & increased salinity makes the water dense enough to sink (downwelling)
* transporting roughlt 96 GT/C a year of CO2 from the oceans surface to deep ocean stores where it can remain for hundreds of years
* this allows for more diffusion to occur at the surface helping to regulate the carbon stored in the atmosphere
64
# The Physical Carbon Pump Process
4. regulating
* where cold, dense currents flow slowly through & between the Atlantic, Southern, Inidan & Pacfic Ocean basins, distributing heat, salt & co2 stores around the globe
65
the thermohaline circulation ensures ......
* the thermohaline circulation ensures CO2 is constantly ebing exchanged betwee the ocean & the atmosphere, acting as an enornmous carbon pump
66
# The Physical Carbon Pump Process
5. upwelling & co2 release
* through upwelling & urbulence created by surface winds,
* previously stored carbon in the intermediate & depp ocean stores return to the surface
* where they warm & release CO2 to the atmosphere
* thus the conveyor is closed & cycle repeats
67
for ur memory, what are the 5 stages of the phsyical carbon pump
* 1) w - warm surface water
* 2) h -high lat cooling, co2 uptake & brine rejection
* 3) d - downwelling
* 4) r - regulating
* 5) u - upwellig & co2 release
* will huddy do rad universe!
68
# Explain the issues of the Physical Carbon Pump
Coral bleeching
* especially along the equator, more carbon in the atmosphere, which goes into the coral, & too much bleaches it
69
# Explain the issues of the Physical Carbon Pump
ice sheets
* ice sheets melting
* brings more freshwater into the ocean
* so thsi freshwater dilutes the salty water
70
# Explain the issues of the Physical Carbon Pump
Gulf Stream affected
* During 2004, the North Easterly Atlantic current, the Gulf Stream, appeared to stall for 10 days,
* evidence shows that the speed of oceanic circulation between the Gulf of Mexico & Europe had slowed by 30% since 2000
71
What drives the Biological carbon pump
organisms, in particular, phytoplankton
72
The biological carbon pump involves....
* marine organisms, photosynthesising, respiring, consuming, producing waste, dying & decomposing
73
What are phytoplankton
* microscopic, single-celled organisms that drift in the sun-lit surfaces of the world's oceans
74
What is generated through photsynthesis by phytoplankton
Phytoplankton, use sunlight to turn carbon into organic matter
75
The carbon generated by phtoplankton in photosynthesis then enters...
the marine food web
76
Living organisms move carbon from the atmosphere to...
the shallower ocean, then the deep ocean when they die & sink down as marine snow
77
Define marine snow
a shower of organic material falling from the upper waters, to the deep ocean (twilight zone)
78
The biological pump doesn't move as much carbon as its very....
seasonal
79
In certain areas of the palnet, you aren't going to get much........occurring in these areas, where its really...
* photosynthesis
* dark, in the cold ocean
80
In winter months, more carbon being....
absorbed & more death occurring
81
# The carbonate pump
What can be found in the ocean which is important to the ocean carbon cycle
* the ocean naturally contains many dissolved chemicals which are especially important to the ocean carbon cycle, & the sheel building organisms that live in the oceans
82
Give examples of species that use calcium carbonate to build their shells
coral, oysters, lobsters & some species of plankton
83
Some marine organisms use ........ to make shells
Calcium Carbonate, CaCO3
84
What are the calcium carboante ions in the water a result of
Chemical reactions that take place when C02 dissolves in the water
85
When these organisms die, they sink...... , so the carbon....
to the ocean floor
enters the deep ocean
86
Eventually, tectonic processes of ...........&........ transform these sediments into......
high heat & pressure
limestone
87
Why can carbon fluxes vary
* Biological carbon can be stored in soils in the form of dead organic matter, or returned back to the atmosphere as a form of decomposition
* depending on the nature of the soil, this process can be relatively quick (e.g a few years), or as in tundra soils, very slow
88
What can trigger rapid releases of carbon stores
deforestation & land use change
89
# Mangroves as a carbon sink
Where can mangroves be found
along tropical & sub-tropical tidal coasts in Africa, Australia, Asia & the Americas
90
Give a statistic that shows that magroves can be a carbon sink
They are vital processors, sequestering almost 1.5 metric tonnes of carbon per hectare, every year, as CO2 is taken in during photosynthesis
91
What can be found in mangrove soils
* thick organic layers of litter, humus & peat, which contain high levels of carbon - over 10%
92
Undisturbed mangroves grow.........& absorb........
* quickly
* large amounts of carbon
93
# Mangroves can be carbon sources
Mangroves soils are.....
anaerobic
94
How are mangrove stores anaerobic
* soils are submerged below high tides twice a day
95
How can mangroves be carbon stores
* there soils are largely anaerobic
* & bacteria & microbes cannot survive without oxygen,
* so the decomposition of plant matter is slow, as a result,
* little of the carbon store can be repired back to the atmsophere & the store remains in tact
96
What enhances the long jevity of mangrove carbon stores
* Any plant matter trapped by tree roots tend to stay as it decomposes slowly, & may remain stored for thousands of years
97
However, if mangroves are drained or cleared,....
carbon can be released back to the atmosphere
98
Give a statistsic which describes how mangroves can be carbon sources
* If just 2% of the worlds mangroves are lost, the amount of carbon released will be 50 times the natural sequesteration rate
99
Why are mangroves being cleared throughout the tropical world
* tourism, shrimp farms & agriculture
100
How can tundra soils be carbon stores
* much of the soil in the tundra region is permanently frozen & contains ancient carbon
* microbe activity is only active in the surface layer of the soil when it thaws
* the rest of the time the roots, & dead & decayed organic matter are frozen locking any carbon into an icy store
101
Tundra soils contain carbon that has been trapped for...
hundreds of thousands of years
102
Tropical forests are huge carbon sinks, but are .......&.......................
fragile & can disappear
103
Where is carbon within rainforests mainly stored
* trees, plant litter & dead matter
104
Describe the soil composition in rainforests
Relatively thin & lacking in nutrients, because litter layers that cover them, though very deep, decompose rapidly & the nutrients released are rapidly consumed by vegetation
105
Why does a carbon store in the soil not develop in the rainforest
* As the litter & dead wood decay, they are recycled very quickly
* Even carbon given off by decomposers is rapidly recycled
106
Give a statistic to evidence that rainforests are major carbon sinks
* Tropical rainforess absorb more atmsopeheric CO2, than any other terrestrial biome,
* accounting for 30% of global net primary production (30% of the planet’s plant growth (biomass) which stores carbon and supports huge biodiversity)
* although they cover just 17% of the earth's surface
107
Define positive feedback
when a change leads to a strengthening of a system
108
Give 2 examples of positive feedback
* dying forests & warming oceans emit CO^2 which in turn warms the planet further
109
Define negative feedback
* when a change leads to the diminishing of a system
110
Give an example of negative feedback
* warmer temperatures result in increased vegetation growth which reduces atmospheric carbon
111
What is the goldilocks zone
* the earth is described as being in the Goldilocks zone in the solar system
* because Earth's temperature is just right,
* the heat from the sun has warmed the planet to a point that can support life
112
What is the natural greenhouse effect responsible for
* For keeping our planet at a suitable temperature; the earth's average temperature is 15 degrees
* Without the GHE, it would be -6 degrees
113
# Explain the Natural Greenhouse Effect
1. Sun enters earths atmopshere
* As the sun's energy enters the atmosphere, clouds reflect some of it back
* only about 1/2 of it reaches the earth's surface & lower atmosphere
114
# Explain the Natural Greenhouse Effect
2. Lower atmosphere
* this energy is able to pass through the denser gases of the lower atmosphere because of it short wavelength
115
# Explain the Natural Greenhouse Effect
3. heat energy
* Infrared is then emitted back towards space from the earth's surface, but at a longer wavelength
* which means that it has difficulty travelling through the denser gases such as CO^2 & methane
* so the atmosphere absorbs the heat
116
# Explain the Natural Greenhouse Effect
4. warming
* this warms the lower atmosphere, the land & the sea
117
The natural greenhouse effect is felt the most at the..... & least at the.....
* equator
* poles
118
What is radiative forcing
* the difference between insolation (sunlight), absorbed by the earth
* & the energy radiated back to space
119
What is the current rate of the enhanced greenhouse effect
* it usually takes the planet around 5,000 years to warm up again after an ice age (by 4-7 degrees)
* the present warming rate is estimatedly 8 X faster
120
Nmae 3 global controls of climate
* latitude
* ocean currents
* atmospheric circulation
121
Name 2 local controls of climate
* albedo
* altitude
122
Describe the air in low pressure systems
* warm air rising
* which cools & condenses to form clouds & rain
123
Describe the air in high pressure systems
* cool dense air sinks
* dry clear weather
124
Almost all life on earth depends on....
photosynthesis
125
Why does almost all life on earth depend on photosynthesis
* Producers, who make their own energy by photosynthesis, form the base of the foodchain
126
# Oceanic & Terrestrial Photosynthesis
How are carbohydrates formed
* In the cells of autotrophs (producers) by combining CO^2, water & light energy from the sun
127
# Oceanic & Terrestrial Photosynthesis
Photosynthesis & respiration both cycle....
CO^2 & O^2 between the oceans, atmosphere & the biological world
128
# Terrestrial Photosynthesis
CO^2 is stored in ............ that is buried in the ......
* organic matter
* soil
129
# How does carbon move through terrestrial ecosystems
1. producers
* Primary producers - plants take carbon dioxide out of the atmosphere through photosynthesis & release oxygen back into the atmosphere trhough respiration
130
# How does carbon move through terrestrial ecosystems
2. consumers
* When consumer animals eat plants, carbon from the plant beomes part of its fats & proteins
131
# How does carbon move through terrestrial ecosystems
3. organisms die
* After plant & animal death, tissues such as leaves decay further than more resistant structures such as wood
132
# How does carbon move through terrestrial ecosystems
4. waste
* Micro organisms & detritus feeders (such as beetles) feed on waste material from animals & this becomes part of these as micro-organisms
133
# How does carbon move through terrestrial ecosystems
5. decomposition
* decomposition is fastest in tropical climates with high rainfall, temperatures & oxygen levels
134
Why is carbon vital in soils
* organic matter is the medium by which carbon passes through the system
* & it also supports micro-organisms that
* maintain the nutrient cycle, breakdown organic matter & enhance plant growth
135
List some characteristics of healthy soils
* retain moisture
* contain more carbon or organic matter
* improve resilience to wetter weather
* contain many worms & other organisms
* sequester carbon
136
What has been the single greatest change to the balance of the carbon cycle
* burning of fossil fuels
137
The IPCC estimates that current rates of warming are .... times faster than the naturally changes previously experienced by the planet
8
138
# What are the possible implications of a 2degree global rise in temp
Hydrological Cycle - precipitation
* rivers will dry up in areas of reduced precipitation,
* & contrastingly, heavy precipitation events may occur more often too
139
# What are the possible implications of a 2degree global rise in temp
Hydrological Cycle - shifts in air pressure
* a shift of sub-tropical high pressure areas northwards will cause a 20-30% decrease in water availability in Mediterranean climate zones
140
# What are the possible implications of a 2degree global rise in temp
Hydrological Cycle - glaciers
* small glaciers will dissappear, decreasing river discharges once they have gone e.g the Himalayas
141
# What are the possible implications of a 2degree global rise in temp
Ecosystems - extinction
* habitat land changes wil mean 10% of land species with limited adaptability will face extinction as the climate gets warmer & either wetter or drier
* rates of extinction could rise to 15-40% of all regions
142
# What are the possible implications of a 2degree global rise in temp
Ecosystems - habitats
* biodiversity will be affected as habitats shift poleward or into deeper ocean waters or higher altiitudes
* e.g tunda biome will be affected by thawing permafrost
143
# What are the possible implications of a 2degree global rise in temp
Ecosystems - consequences of shifting climate zones
* the shift northward of climate zones is at a rate of 6.1 km per decade
* marine diversity may be lost as fish move away from warming sea temperatures
144
# What are the possible implications of a 2degree global rise in temp
Ecosystems - coral
* about 80% of coral reefs could be bleached
* acidification of seawater (carbonic acid) will threaten corals & the shells of marine creatures will get smaller & thinner
145
# What are the possible implications of a 2degree global rise in temp
Ecosystems - plants
* plant changes will lag behind animal changes, as they cannot move, & they will face pests & diseases wheer there is less cold weather to kill them
146
# What are the possible implications of a 2degree global rise in temp
Climate - Artic temperatures
* the Artic's average temperature has already increased at twice the global average over the last 200 years
* -snow & ice will contract with the abolition of glaciers
147
# What are the possible implications of a 2degree global rise in temp
Climate - drought
* drought will become more common in the tropics & subtropics, but some uncertainties will remain e.g El Nino
148
# What are the possible implications of a 2degree global rise in temp
Climate - hydrological cycle
* precipitation patterns will change:
* will increase in higher latitudes & decrease in lower latitudes
149
# What are the possible implications of a 2degree global rise in temp
Climate - storm activity
* tropical zones may experience stronger storm activity as a result of more intense heat energy & moisture in the atmosphere
* inc more intense tropical cyclones & stronger mid-latitiude westerly winds
