The Carbon Cycle Flashcards
(81 cards)
1
Q
Reasons for deforestation?
A
Timber Agricultural land Hydroelectric power Mineral exploitation Wildfires Infrastructural expansion Palm oil plantations
2
Q
What percentage of Carson emissions does deforestation account for?
A
20%
3
Q
What impact does photosynthesis have on stores?
A
Reduction in photosynthesis
Forest clearing accelerated the decay of dead wood
4
Q
What crop is most responsible for methane emissions?
A
Rice. 20%.
5
Q
What country has the highest agricultural carbon emissions?
A
China.
6
Q
How much carbon did farmers emit in 2011?
A
6 billion tonnes of greenhouse gas
Accounts for 13% of global emissions
7
Q
What impact does agricultural activities have on stores?
A
Atmosphere stores increase so all transfer out of this store also increase.
8
Q
What percentage of the population are set to be living in urban areas by 2030?
A
60%
9
Q
How are petrol and gas formed?
A
Marine organisms sinking to the bottom and compressing under pressure.
10
Q
How is coal formed?
A
From plants
11
Q
What elements do fossil fuels contain?
A
Carbon and Hydrogen
12
Q
What’re the main contributors
A
America Australia Canada Saudi Arabia Kazakhstan UAE
13
Q
What percentage of carbon dioxide emissions does cement manufacture account for?
A
8%
14
Q
What rock is used for the production of cement?
A
Limestone
15
Q
What is calcination?
A
Occurs when limestone is heated, breaking down into calcium oxide and CO2. This accounts for 50% of all emissions in cement production.
16
Q
What is the single largest contributor to atmospheric carbon dioxide?
A
Burning of fossil fuels (coal, oil and gas)
17
Q
What percentage of carbon emissions are from China?
A
28%
18
Q
What percentage of carbon emissions come from the USA?
A
14%
19
Q
What percentage of carbon emissions come from India?
A
7%
20
Q
How much have carbon emissions increased?
A
From 280ppm to 400ppm.
21
Q
What is the effect of increasing carbon dioxide emissions?
A
Enhances the natural greenhouse effect.
22
Q
2013 carbon emissions?
A
43% coal, 33% oil and 18% gas with all these fossil fuels needing to be extracted from other sources.
23
Q
Define organic carbon
A
Found in living organisms e.g. plants, trees, animals
24
Q
Define inorganic carbon
A
Carbon found in non-living things e.g. sedimentary rocks
25
What is the largest carbon sink?
Marine sediments and sedimentary rocks 66000000 to 100000000 billion metric tonnes
2/3 of all stores
26
What are some important carbon compounds?
```
Carbon dioxide
Methane
Calcium carbonate
hydrocarbons
bio-molecules
```
27
What units are used for carbon in various stores?
1 gigatonee = 10*9 tonnes (1 billion tonnes)
28
What units are used to measure atmospheric carbon?
Atmospheric carbon is measured in parts per million.
29
How do marine organisms use carbon?
Marine organisms use ocean carbon, in the form of calcium carbonate to produce shells.
30
What are the main inorganic forms of carbon in the lithosphere?
Fossil fuels like coal, oil and natural gas, oil shale and carbonate based sedimentary deposits such as limestone.
31
What are the organic forms of carbon in the lithosphere?
Litter, organic matter and humic substances.
32
How much carbon does the atmosphere hold?
720 Gtc - 800 Gtc
33
What is the long term carbon cycle?
100-200 million years
Carbon dioxide in the atmosphere combines with water vapour to produce carbonic acid
Makes rainfall slightly acidic
Reacts with minerals in rocks causing chemical weathering
Molecules produced in this reaction enters the hydrosphere
Oceans absorb carbon
Carbon enters the shells of marine organisms as calcium carbonate
When these organisms die they sink, compact down and form sedimentary rocks e.g. limestone
Carbon converted into fossil fuels = sequestration
Stores in rocks of the lithosphere
Carbon released at destructive plate boundaries
returned to the atmosphere during volcanic reactions
34
What is the short term carbon cycle?
Moves more than 100-900 more carbon than long term
Process that powers all life
Photosynthesis making carbohydrates
As broken down, carbon dioxide is released during respiration
Decomposition - bacteria and fungi break down carbohydrates releasing carbon dioxide and methane back into the atmosphere.
1 million to 1 billion metric tonnes of carbon move through the fast carbon cycle every year.
35
What is a carbon sink?
If more carbon enters a store than leaves it, that store is considered a net carbon sink.
36
What is a net carbon source?
If more carbon leaves a store than enters it, that store is considered a net carbon source.
37
What is the geological component?
Where it interacts with the rock cycle in the process of weathering, burial, subduction and volcanic eruptions.
38
What factors drive changes in the magnitude of stores over time and space?
```
Photosynthesis
Respiration
Decomposition
Combustion
Burial and compaction
Carbon sequestration
Weathering
```
39
What is photosynthesis?
carbon dioxide + water + sunlight = glucose + oxygen
turn carbon into organic matter e.g. carbohydrates which store energy
carried out by phytoplankton, terrestrial plants, algae and bacteria
40
What is respiration?
Use stored carbohydrates as an energy store
Oxygen + Glucose = energy + water + carbon dioxide
carbohydrates remains in plants as biomass
41
What is decomposition?
Physical, chemical and biological mechanisms that transform organic matter into increasingly stable forms which are then fuel for respiration.
also referred to as microbial respiration
decomposing plants release carbon dioxide (in the presence of oxygen)
in the absence of oxygen, methane is produced
bacteria and fungi feeding on dead organisms respire and release carbon dioxide back into the atmosphere
the elements released may become part of the soil solution, and some may react with chemicals of soil or rock particles before becoming part of living things again through reabsorption by plants.
42
What is combustion?
What organic material (contains carbon) is burnt in the presence of oxygen it is converted into energy, carbon dioxide and water.
43
What is burial and compaction?
Organic matter is buried by sediments and becomes compacted.
These organic sediments containing carbon may form hydrocarbons such as coal and oil.
Marine organisms convert carbon to calcium carbonate, when they die their shells accumulate on the sea bed.
Some of the carbonates dissolve, releasing CO2.
Rest become compacted to form limestone, storing carbon for millions of years.
44
What is carbon sequestration?
Used to describe the transfer of carbon from the atmosphere to plants, soils, rock formation and oceans.
Natural and human procress
45
What is weathering?
Involves the breakdown or decay of rocks in their original place or close to the surface
When CO2 is absorbed by rainwater it forms a mildly acidic carbonic acid
Rocks will slowly dissolve with the carbon in being held in the solution.
Transported to oceans via the water cycle, it can be used to build the shells of marine organisms.
46
What are temporal scales?
Time scales such as durnal scales (daily) and annual scales as well as fats and slow cycles.
47
What are spatial scales?
Geographical scales such as the plant (local/micro scale), sera’s and continental scale.
48
Define sere?
A succession that relates to a specific to a specific environment is called a sere.
49
Define seral stage?
Each stage in the succession e.g. hydrosphere, psammosere.
50
What is the physical carbon pump?
Movement of carbon from atmosphere to surface waters to deep ocean and back again, through ocean currents. E.g. the Gulf Stream and the upwelling and downwelling of water.
51
How does temperature effect waters ability to absorb carbon?
As the temperature of water decreases, it can absorb more CO2.
52
What is vertical deep mixing?
The important movement of carbon within the oceans between deep oceans and surface water which allows carbon to be moved between the ocean and the atmosphere.
53
Define thermophaline circulation?
The component of general oceanic circulation controlled by horizontal differences in temperature and salinity.
54
What is the Biological carbon pump?
Movement of carbon between atmosphere and ocean, and within the ocean, through biological processes such as photosynthesis, respiration and decomposition.
55
Describe the processes involved in the biological carbon pump?
Living things move carbon from the atmosphere into surface waters
Carbon is incorporated into marine organisms or organic matter or structural calcium carbonate.
When organisms die, their dead cells, shells and other parts sink into deep water.
Decay releases carbon dioxide into this deep water
Some material sinks straight to the bottom, forming layers of carbon rich sediments
Over millions of years, chemical, rocks, locking up carbon.
56
Howare phytoplankton and zooplankton important in the carbon cycle?
50% of all photosynthesis (phytoplankton) and so account for 50% of all oxygen in the atmosphere.
57
What is the equation for combustion?
hydrocarbon + oxygen = water + carbon dioxide
58
Explain the relationship between forests and carbon dioxide emissions?
Each year fires burn 3 to 4 million km*2.
Forest fires consume about 10-20% of the carbon and immediately emit it into the atmosphere. New trees grow, storing carbon, old trees decompose, emitting carbon and the organic layer of the soil accumulates, storing carbon.
59
Explain the relationship between volcanic activity and carbon dioxide emissions?
Warming effect of carbon dioxide is counterbalanced by sulphur dioxide given out. Conversion of this to sulphuric acid increases reflection of radiation from the sun into space, cooling the Earth's lower atmosphere.
The amount of carbon dioxide released have not been enough to produce detectable global warming.
Releases less than 1% of the carbon dioxide released by human activities.
60
What is the global carbon budget?
The carbon budget uses data to describe the amount of carbon that is stored and transferred within the carbon cycle.
61
What is carbon usually measured in?
In units of mass called petograms (Pg). 1 petogram is equal to 1 Gigatonne (1 billion tonnes).
62
What is carbon sequestration?
The process of carbon sequestration involves capturing carbon dioxide from the atmosphere and putting it into long-term storage. There are two types: geologic sequestration and terrestrial/Biologic Sequestration.
63
What is geologic sequestration?
Carbon Dioxide is captured at its source and then injected in liquid form into stores underground e.g. depleted oil or gas reservoirs, coal seams, deep salt formation and the deep ocean.
64
Why is the ocean effective at absorbing carbon?
Carbon is 'sunk' and then circulates over thousands of years. It has entered the Earth's geologic cycle by the time it reaches the sea bed.
65
What is Terrestrial/Biologic Sequestration?
Involves the use of plants to capture carbon dioxide from the atmosphere and then store it in the stems and roots of the plants as well as in the soil.
66
Describe the Greenhouse Effect
Solar radiation passes through the clear atmosphere
Some solar radiation is reflected by the atmosphere and earth's surface
Some of the infrared radiation passes through the atmosphere and is lost in space.
Some of the infrared radiation is absorbed and re-emitted by the greenhouse gas molecules. The direct effect is the warming of the Earth's surface and troposphere.
Solar radiation is absorbed by the earth's surface and warms it. It is converted into heat causing the emission of longwave infrared radiation back into the atmosphere.
67
What is radiative forcing?
The enhanced greenhouse effect is where the extra carbon dioxide and other greenhouse gases in the atmosphere causes radiative forcing. This is the amount that the Earth's energy budget is out of balance.
68
Discuss ocean acidification
Since 1950, ocean pH has dropped by 0.1 to an average of 8.1.
30% of atmospheric carbon gets sunk into the ocean.
When carbon dioxide dissolves into oceans it reacts with carbonate ions to form bicarbonate.
This removes free carbonate ions, which can be used to build many marine organisms.
Dissolving calcium carbonate shells and skeletons makes them more susceptible to disease, reduces coral growth, impacts on food webs
Reduced shellfish catches - loss of fishing industry
Damage to coral reefs may reduce their role as natural sea defences from erosion and sea level rise.
69
Positive feedback loop for ocean acidification
more acidic oceans = less carbonates for organisms to build shells etc = weakening of biological pump = more CO2 in atmosphere
70
Negative feedback loop for carbon dioxide and the ocean?
More carbon dioxide in atmosphere = more chemical weathering attacks rocks = releases more carbonate ions into ocean = strengthening of biological pump/marine food chain = more carbon dioxide removed from the atmosphere.
71
Positive feedback loop to do with Ocean Warming?
Warm oceans = decrease abundance of phytoplankton = take less carbon from the atmosphere through the biological pump (weakening of biological pumps) = more carbon in atmosphere/ocean less of a sink
72
Negative Feedback loop for Ocean Warming?
More carbon dioxide in atmosphere = used for plant and phytoplankton growth = takes carbon dioxide directly from the water = less carbon dioxide in oceans.
73
General negative feedback loop for rising temperatures?
Rising temperatures = increased evaporation = increased cloud cover = increased albedo of earth = cooling
74
Discuss melting sea ice?
In the last 35 years, sea ice in the Arctic has retreated by 40%
Highly reflective sea ice is replaced by more heat absorbent water. Water absorbs more sunlight, which amplifies warming
75
Impacts on ocean salinity?
Melting land ice adds fresh water to the North Atlantic Ocean. Freshwater is less dense than saline water so doesn't sink as easily. Therefore, a reduction in salinity in the North Atlantic is likely to weaken and slow down the North Atlantic current.
76
What are unilateral commitments?
'cap and trade format'. Individual industries/companies are allocated a capped emission allowance per year (which declines over time). Fined if they emit over their cap.
77
What are bilateral commitments?
In 2014, the largest emittors (USA and China) signed a secretly negotiated agreement to limit their emissions.
78
Examples of measures taken to reduce carbon dioxide emissions?
National carbon targets e.g. USA agreed to reduce carbon dioxide emissions by an average of 27% by 2025, on 2005 baseline emission
Renewable energy
De-investment from hydrocarbon energy stores
Energy efficiency schemes
79
What is The Paris Agreement?
2015. Limit global warming to two degrees celsius above pre-industrial level. Tough, binding carbon dioxide limits.
80
What is the Kyoto Protocol?
Commits state parties to reduce greenhouse gas emissions. Not all developed nations signed up, or withdrew. Countries do not follow the suggested course of action.
81
What is the International Panel on Climate Change?
The IPCC. Synthesises reports every 5-7 years which can be requested by Government.
