Chapter 1 - Water & Carbon Cycle - Complete Flashcards
(157 cards)
1
Q
Define inputs?
A
Energy entering the system
2
Q
Define outputs?
A
Energy leaving the system
3
Q
Define stores?
A
Energy is stored in the system
4
Q
Define flows/transfers?
A
Energy moving around the system
From one store to another
5
Q
Define boundaries?
A
Boundary/limit of the system
6
Q
Define open system?
A
The system has inputs and outputs of energy
7
Q
Define closed system?
A
The system has no inputs or outputs of energy
8
Q
Define dynamic equilibrium?
A
There is a balance between the inputs and outputs of energy
9
Q
Define positive feedback?
A
When the effects of an action are amplified by other knock-on effects
10
Q
Define negative feedback?
A
When the effects of an action are nulllified by other knock-on effects
11
Q
Define attributes?
A
Characteristics of the elements that may be perceived and measured
12
Q
Define relationships?
A
Associations that occur between elements and attributes
13
Q
Name the 6 spheres?
A
- Atmosphere - Air around us
- Lithosphere - Earth/land
- Cryosphere - Ice/glaciers
- Biosphere - Plants/animals
- Hydrosphere - water
- Pedosphere - soil/ground
14
Q
Define cascading system?
A
Output of one system is the input of the next system
15
Q
Solid –> Liquid
Tricky one
melting
A
Ablation
16
Q
Liquid –> Solid
Tricky one
A
Accumulation
17
Q
Solid –> Gas
Tricky one
A
Sublimation
18
Q
Gas –> Solid
Tricky one
A
Deposition
19
Q
Gas –> Liquid
Easy one
A
Condensation
20
Q
Liquid –> Gas
Easy one
A
Evaporation
21
Q
What percentage of freshwater is on earth?
A
> 3%
22
Q
What percentage of freshwater is in:
- cryosphere
- groundwater
- liquid freshwater
- Water vapour in atmosphere
A
- cryosphere - 69%
- groundwater - 30%
- liquid freshwater - 0.3%
- Water vapour in atmosphere - 0.04%
23
Q
Is the global hydrological system open or closed?
A
A closed system
24
Q
Percentage of water stored on earth: Ice caps Groundwater Lakes Soil moisture Atmosphere Swamps Rivers
A
Ice caps - 69.56% Groundwater - 30.10% Lakes - 0.25% Soil moisture - 0.05% Atmosphere - 0.04% Swamps - 0.03% Rivers - 0.006%
25
Define drainage basin?
Is an area of land drained by a river and its tributaries.
26
Define the boundary of a drainage basin?
The watershed
27
Are drainage basins open or closed systems?
Open systems
28
Define 1 input of water into a drainage basin?
- PRECIPITATION(rain, snow, hail, dew, frost)
29
Define 5 stores of water in a drainage basin?
- INTERCEPTION (Vegetation intercepts rainfall)
- VEGETATION STORAGE (Water stored in plants)
- SURFACE STORAGE (puddles, ponds, lakes)
- GROUNDWATER (aquifers, water table)
- CHANNEL (river, stream)
30
```
Define 10 flows of water in a drainage basin?
I
S
T
S
T
P
G
B
I
C
```
- INFILTRATION (Water soaks into land)
- SURFACE RUN-OFF (Water flowing over the land)
- THROUGHFALL (Water dripping from plant to plant)
- STEMFLOW (Water moving down plant stem)
- THROUGHFLOW (Water moving through ground downhill)
- PERCOLATION (Water seeping through rocks)
- GROUNDWATER FLOW (Water flowing through ground to the watertable)
- BASEFLOW (groundwater flow that feeds into rivers)
- INTERFLOW (Water flowing downhill through permeable rock above water table)
- CHANNEL FLOW (Water flowing through rivers or streams
31
Define 4 outputs of water in a drainage basin?
- EVAPORATION (Water turning into water vapour)
- TRANSPIRATION (Evaporation within leaves)
- EVAPOTRANSPIRATION (Evaporation & transpiration together)
- RIVER DISCHARGE (River flow)
32
Define the water balance?
| Water in dynamic equilibrium
- Balance of inputs & outputs
- Wet seasons, precipitation exceeds evapotranspiration (WATER SURPLUS)
- Drier seasons, precipitation is lower than evapotranspiration (WATER DEPLETION)
- End of dry season, deficit of water (GROUND STORE RECHARGE)
33
```
Name the 4 processes where the magnitude of the stores varies over TIME & SPACE?
E
C
C&P
CP
```
- Evaporation
- Condensation
- Cloud formation & precipitation
- Cryospheric processes
34
Define EVAPORATION for the magnitude of the stores varies over TIME & SPACE?
- Liquid water changes into gas (water vapour)
- Magnitude of the evaporation flow varies by location and season.
- More solar radiation, large supply of water and warm/dry air, higher evaporation.
- Little solar radiation, little available liquid water and cool air, lower evaporation.
35
Define CONDENSATION for the magnitude of the stores varies over TIME & SPACE?
- Occurs when water vapour turns to liquid (dew point)
- Water droplets flow into other subsystems, decreases water stored in atmosphere.
- Magnitude of condensation flow depends on amount of water vapour in atmosphere & temperature.
36
Define CLOUD FORMATION & PRECIPITATION for the magnitude of the stores varies over TIME & SPACE?
- Precipitation is main flow from atmosphere to ground.
- Clouds form when warm air cools down, water vapour condenses to droplets making clouds.
- Water droplets from condensation too small to form clouds. Needs dust/soot to be cloud condensation nuclei. Give water droplets a surface to condense on.
37
What 3 factors cause warm air to cool, leading to precipitation?
- Other air masses (Warm air less dense than cool air, warm air forces up above cool air. Cools down as it rises. FRONTAL PRECIPITATION)
- Topography (Warm air meets mountains, forced to rise, causing it to cool. OROGRAPHIC PRECIPITATION)
- Convection (Sun heats the ground, moisture on ground evaporates and rises in column of warm air and cools down. CONVECTIVE PRECIPITATION)
38
Define CRYOSPHERIC PROCESSES for the magnitude of the stores varies over TIME & SPACE?
- Accumulation & ablation change amount of water stored in cryosphere.
- Colder periods, inputs are greater than outputs in cryosphere.
- Warmer periods, magnitude of stores reduces as losses due to melting larger than inputs of snow.
- Earth emerging from glacial period, extensive stores of ice sea ice and on land.
39
Define river discharge?
Volume of water m^3 that flows in a river per second
40
Define peak discharge?
Highest point on the hydrograph, when the river discharge is at its greatest.
41
Define a hydrograph?
Graphs of river discharge over time.
Show volume of water flowing at certain point in time.
42
Define flood hydrograph?
Shows hydrograph of river discharge around a storm event, only covers short period of time.
43
Define lag time?
Delay between peak rainfall and peak discharge.
Delay caused from time rainwater flows from ground to the river.
Shorter lag time increases peak discharge as more water gets to river during shorter period of time.
44
Define rising limb?
Part of hydrograph up to peak discharge.
River discharge increases as rainwater flows into river.
45
Define falling limb?
Part of hydrograph after peak discharge.
River discharge is decreasing due to less water flowing into the river.
46
Define the size of a drainage basin?
Larger drainage basins catch more precipitation, have higher peak discharge.
47
Define the shape of a drainage basin?
Circular basins have flashy hydrograph.
| Long/ narrow basins, not flashy hydrograph.
48
Define ground steepness?
Water flows quicker downhill in steep-sided drainage basins.
49
Define 4 SEASONAL CHANGES AND VEGETATION physical factors affecting the water cycle?
- Size of inputs, flows, stores in water cycle vary with seasons.
- During winter, water can freeze, reduce the size of flow through drainage basin.
- Vegetation intercepts precipitation and slows movement to river.
- More vegetation means more water lost through evapotranspiration, reducing peak discharge.
50
Define 4 FARMING PRACTICES human factors affecting the water cycle?
- Ploughing breaks up surface, more water can infiltrate.
- Crops increase infiltration and interception, reduce runoff. Evapotranspiration increases.
- Livestock trample ground, decrease infiltration, increase runoff.
- irrigation increase runoff. Groundwater levels reduced if used for irrigation.
51
Define 2 LAND USE CHANGES human factors affecting the water cycle?
- Deforestation reduces water being intercepted by vegetation. Decreases infiltration, increases runoff.
- Construction of buildings and roads create impermeable surfaces reducing infiltration. Increases runoff, water moves quicker through system, increased flooding.
52
Define 2 WATER ABSTRACTION human factors affecting the water cycle?
- More water is abstracted to meet demands and reduces water in stores.
- Dry season more water is abstracted from stores, stores are depleted further.
53
How is carbon stored in the LITHOSPHERE?
- Sedimentary rocks (limestone)
| - Fossil fuels ( coal, oil)
54
What 2 elements is carbon stored as in the ATMOSPHERE?
- CO2
| - CH4
55
How is carbon stored in the HYDROSPHERE?
- Dissolved in rivers, lakes, oceans
56
How is carbon stored in the BIOSPHERE?
- Living organisms
| - Soil
57
How is carbon stored in the CRYOSPHERE?
Permafrost
| Ice
58
Is the carbon system open or closed?
Closed system
59
Define the change in size over time of carbon for PHOTOSYNTHESIS?
- Transfers carbon from atmosphere to biomass.
- Plants & phytoplankton use energy from sun to grow.
- Carbon passed through food chain through respiration & decomposition.
60
Define the change in size over time of carbon for RESPIRATION?
- transfers carbon from living organisms to atmosphere.
| - Plants & animals break down glucose for energy-releasing CO2 & CH4.
61
Define the change in size over time of carbon for COMBUSTION?
- Transfers carbon in biomass to atmosphere by burning.
| - Wildfires causes carbon flow.
62
Define the change in size over time of carbon for DECOMPOSITION?
- Transfers carbon from dead biomass to atmosphere and the soil.
- Carbon transferred to soil in the form of HUMUS.
63
Define the change in size over time of carbon for OCEAN UPTAKE & LOSS?
- CO2 directly dissolved from atmosphere to ocean.
| - Carbon transferred from ocean to atmosphere when carbon-rich water from deep oceans rises to surface releasing CO2.
64
Define the change in size over time of carbon for WEATHERING?
- Transfers carbon from atmosphere to hydrosphere & biosphere.
- Atmospheric carbon reacts with water vapour to form acid rain. Acidic rain breaks down rocks in SITU.
- Calcium carbonate formed in sea to help grow sea creatures shells.
65
Define the change in size over time of carbon for SEQUESTRATION?
- Carbon from atmosphere can be sequestrated in sedimentary rocks or as fossil fuels. Formed when dead animals and plants get compacted at bottom of ocean.
- Carbon in fossil fuels is sequestrated until we burn them.
66
```
Define fast carbon flows?
P
R
C
D
```
- Flows quickly between stores in minutes, hours or days.
| - Photosynthesis, Respiration, Combustion, Decomposition.
67
Define slow carbon flows?
takes millions of years for carbon to be sequestrated in sedimentary rocks.
68
Define 2 natural processes that change the carbon cycle?
- Wildfires
| - Volcanoes
69
Define how wildfires change the carbon cycle?
- Transfers carbon from biomass to atmosphere. Loss of vegetation decreases photosynthesis, less carbon removed from atmosphere.
70
Define how volcanoes change the carbon cycle?
- Carbon stored in Earth magma released by volcano erupting and carbon enters atmosphere.
71
```
Define 4 human processes that change the carbon cycle?
H
D
F
L
```
- Hydrocarbon extraction & use
- Deforestation
- Farming practices
- Land use changes
72
Define how hydrocarbon extraction & use change the carbon cycle?
- Extracting & burning fossil fuels release CO2 to atmosphere.
- Without human intervention, carbon remains sequestrated in lithosphere for millions of years.
73
Define how deforestation changes the carbon cycle?
- Forest cleared by agriculture, logging.
| - Clearance reduces size of carbon store forest burned then rapid flow of carbon from biosphere to atmosphere.
74
Define how farming practices change the carbon cycle?
- Animals release CO2 & methane when they respire & digest food.
- Ploughing releases CO2 stored in soil.
- Growing rice paddies release lots of methane.
75
Define how land use changes change the carbon cycle?
- vegetation is removed and replaced with buildings - reduces carbon store in biosphere.
- Concrete production releases lots of CO2.
76
Define the carbon budget?
The difference in the inputs & outputs of carbon into a subsystem.
77
Define how the carbon cycle affects the atmosphere & climate?
- Affects amount of gases containing carbon in the atmosphere. (greenhouse gases trap suns energy-storing heat warming the planet).
- Human activity increasing greenhouse gases in atmosphere and temperatures expected to rise (global warming).
78
Define how the carbon cycle affects the land?
- Allows plants to grow, if no carbon in atmosphere, plants can't photosynthesis,
- No decomposition leads to no nutrients recycled.
- Changes can reduce amount of carbon stored in land.
- Melting permafrost releases carbon into atmosphere.
- Increase in global temperatures also increase wildfires.
79
Define how the carbon cycle affects the oceans?
- CO2 dissolved directly into oceans from atmosphere.
- CO2 in oceans used by organisms during photosynthesis to form calcium carbonate shells and skeletons.
- Increased CO2 in atmosphere increases acidity in oceans, has effects on marine life.
- Global warming affects oceans, phytoplankton won't survive at higher temperatures.
- Warmer water is less able to absorb CO2.
80
Define the 4 positive feedbacks for the water cycle?
Temperatures rise --> Evaporation increases --> Amount of water vapour in atmosphere increases --> greenhouse effect increases.
81
Define the 4 stages of negative feedbacks for the water cycle?
Temperature rise --> Evaporation increases --> Amount of water vapour in atmosphere increases, causing more clouds to form --> Increases cloud cover reflects more suns energy back into space --> temperature fall.
82
Define the 4 positive feedbacks for the carbon cycle?
Temperatures rise --> respiration rate increases --> amount of CO2 in atmosphere increases --> greenhouse effect increases.
83
Define the 4 negative feedbacks for the carbon cycle?
CO2 in atmosphere increases --> Extra CO2 causes plants to increase growth --> Plants remove and store more CO2 from atmosphere --> Amount of CO2 in atmosphere reduces.
84
Define how climate change affects life on earth?
- Pattern of precipitation to change
- Extreme weather events increased get worse
- Agricultural productivity will decrease
- Sea levels will rise
- Plankton decline
85
Define how individuals have influenced the carbon cycle?
- People choose to use car less and get more fuel-efficient cars.
- Make their homes more energy efficient (double-glazing, insulation)
86
Define how Regions & Nations have influenced the carbon cycle?
- Governments reduce reliance on fossil fuels for powering homes - use more renewable energy.
- Afforestation and restoring degraded forests.
- Governments invest in carbon capture and storage underground in gas reservoirs.
87
Define how everyone globally has influenced the carbon cycle?
- Countries work together to reduce emissions - Paris Agreement.
- International carbon trading schemes - given a limit on emissions produced.
88
Define the IPCC?
| Climate change
Intergovernmental Panel on Climate Change - is an international organisation set up by the UN to share knowledge about climate change.
89
Define facts about Amazon rainforest?
- Worlds largest rainforest
- Covers 40% of South America
- Hot, wet climate lots of vegetation
- Many groups of indigenous people living there
- 1 million plant species, 500+ mammals, 2000 species of fish.
90
Define how the water cycle is important to the Amazon Rainforest environment?
- Water cycle makes it very wet - high precipitation
- Lots of evaporation
- Warm temperatures mean high evaporation
- Dense canopy - high interception - less water reaches river
- Species adapt to high humidity and frequent rainfall
91
Define how the carbon cycle is important to the Amazon Rainforest environment?
- Stores lots of carbon in vegetation (CARBON SINK)
- Increasing CO2 in atmosphere - increased productivity in rainforest bc more photosynthesis - increasing biomass
- CO2 sequestrated has increased (more CARBON STORE)
- Trees growing quickly but dying younger
92
Define how deforestation affects the water cycle in Amazon rainforest?
- Deforested areas have no canopy cover, more water reaches the ground. Too much water soaked up, flooding.
- Reduces rate of evapotranspiration - less water vapour reaches the atmosphere, fewer clouds form and rainfall reduced
- Increased drought
93
Define how deforestation affects the carbon cycle in Amazon rainforest?
- Without roots to hold the soil together, heavy rain washes away nutrient-rich soil, transferring carbon to the hydrosphere
- Less leaf litter, so humus isn't formed - limits carbon being absorbed
- Trees remove CO2 from the atmosphere and store it - fewer trees less carbon absorbed.
94
Define how climate change affects the water & carbon cycle in Amazon rainforest?
- Temperature increasing and rainfall is decreasing - leads to drought
- Plants & animals have to adapt to moist conditions
- More forest fires occur - releases CO2
- 4oC temp rise could kill 85% of Amazon rainforest.
95
# Define the 4 attempts to limit human impacts on the Amazon rainforest?
S
R
E
P
- Selective logging
- Replanting
- Environmental law
- Protection
96
Define SELECTIVE LOGGING to limit human impacts on the Amazon rainforest?
- Only some trees cut
| - Less damaging to the forest than cutting all trees down.
97
Define REPLANTING to limit human impacts on the Amazon rainforest?
- new trees are planted to replace the ones that are cut down.
- Important to plant the same types of trees that were cut down so variety of trees is kept the same.
98
Define ENVIRONMENTAL LAWS to limit human impacts om the Amazon rainforest?
- Laws to ban the use of wood from forests that aren't managed sustainably
- Laws that ban recessive logging
- Laws that control land use
99
Define PROTECTION to limit human impacts om the Amazon rainforest?
Countries set up national parks and nature reserves to protect rainforests.
- Within national parks and nature reserves, damaging activities such as logging can be monitored and prevented.
100
Define a model?
Represents a concept model of what the product might look like.
101
Define a system?
Is the way in which different parts link together in order to work/function.
102
Define cryospheric processes?
Processes that affect the total mass of ice at any scale from local patches of frozen ground to global ice amounts.
Include accumulation and ablation (melting and freezing)
103
Define evapotranspiration?
Is the sum of evaporation from the land surface plus transpiration from plants.
104
Define INFILTRATION?
Water soaks into land
105
Define SURFACE RUN-OFF?
Water flowing over the land
106
Define THROUGHFALL?
Water dripping from plant to plant
107
Define STEMFLOW?
Water moving down plant stem
108
Define THROUGHFLOW?
Water moving through ground downhill
109
Define PERCOLATION?
Water seeping through rocks
110
Define GROUNDWATER FLOW?
Water flowing through the ground to the water table
111
Define BASEFLOW?
groundwater flow that feeds into rivers
112
Define INTERFLOW?
Water flowing downhill through the permeable rock above the water table
113
Define CHANNEL FLOW?
Water flowing through rivers or streams
114
How does the magnitude of the store HADLEY CELL vary over time and space?
- Equator is hottest part of Earth so is where most evaporation occurs.
- Low pressure rises into troposphere, cooling & condenses at Dew point.
- Precipitation occurs above Equator.
- At tropopause, air pushed in direction of either of the tropics.
- This cools the air & becomes denser, sinking over the Tropics (High pressure).
- As the cool air sinks it is met by the warm air from the Earth’s surface and it warms itself.
- Therefore, condensation cannot occur and therefore there is less precipitation over both the Tropic of Cancer and the Tropic of Cancer.
- This warm air is then pushed by the trade winds back towards the Intertropical Convergence Zone above the Equator.
115
Define orographic rainfall?
Warm air meets mountains, forced to rise, causing it to cool forming precipitation.
116
Define rain shadow?
The area on the other side of the mountain in orographic rainfall which this other side receives little/ no rainfall.
117
Define the Hadley Cell?
Atmospheric convection cell where air rises at equator & sinks at medium latitudes (30° north/south)
118
How does the magnitude of the store FRONTAL RAINFALL vary over time and space?
- When a warm front meets a cold front.
- Heavier cold air sinks to the ground on the other side of the orographic landscape and the warm air rises above it. When the warm air rises, it cools. The cooler air condenses and forms clouds.
- Therefore, no condensation can occur and therefore there is less precipitation in the area known as the rain shadow.
- For instance, Grimsby situated East of the Pennines gets less rainfall.
119
How does the magnitude of the store ITCZ vary over time and space?
- Seasonal shifts of ITCZ when the Earth Tilts 23 degrees.
- When ITCZ moves north and sun is overhead in the northern hemisphere, the band of rain moves north from the Equator and the opposite direction when the ITCZ moves south.
- Different geological time periods e.g In the Quaternary Period sea levels were 120 m lower than they are currently. Ice covered large areas on the continents. Now with climate change, the stores of ice are reducing
120
Define tributaries?
A mini river that feeds the main river
121
Define Water stress?
The annual water supply is less than 1700m3 E.g India and South Africa.
122
Define Water scarcity?
The annual water supply is below 1000m3 E.g Egypt and Tunisia.
123
Define Physical water scarcity?
When more than 75% of river flows are used.
124
Define Economic water scarcity?
When human and financial factors limit water use to less than 25% of river flows.
125
Define the river regime?
The variability in its discharge throughout the course of a year in response to Precipitation, Temperature, Water abstraction, dams and drainage basin characteristics.
126
Define temperature climate?
There is a steady discharge throughout the year due to the consistent levels of precipitation.
127
Define Mediterranean climate?
Flashy hydrograph at the start of the year due to the dry ground from the previous summer
128
Define Mountain Climate?
Peak discharge during Summer because the mountain peak snow is melting in the warmer temperatures. This causes more runoff towards the river.
129
Define Equatorial Climate?
Two peaks during the year - one around April and one in October. This is because the Hadley cell shifts over the Equator during the year.
This changes the weather systems and causes greater precipitation at two points in the year.
130
Define the Humid Tropical climate?
Higher discharge around March and April because the area is experiencing the wet season.
Decrease in discharge from August to November (Where it almost flatlines) because this is the dry season.
131
Define Ocean acidification?
- A decrease in the alkalinity/pH of oceans, caused by the uptake of carbon dioxide from the atmosphere, released by burning fossil fuels.
- It occurs because oceans are a carbon sink (absorbs more carbon from the atmosphere than it releases).
132
# Define the sizes of the major stores of carbon?
```
Lithosphere
Hydrosphere
Pedosphere
Cryosphere
Atmosphere
Biosphere
```
```
Lithosphere - 99.985%
Hydrosphere - 0.0076%
Pedosphere - 0.0031%
Cryosphere - 0.0018%
Atmosphere - 0.0015%
Biosphere - 0.0012%
```
133
# Define where the global distribution of the major stores?
```
Lithosphere
Hydrosphere
Pedosphere
Cryosphere
Atmosphere
Biosphere
```
Lithosphere - Hydrocarbons are mainly found concentrated in North America, Former USSR, and the Middle East.
Hydrosphere - Stored in the sea and in rivers, lakes, reservoirs. Carbon stored in the sea and calcification happens. Carbon in the Atlantic and Bay of Bengal, as the warm Gulf Stream keeps carbon rising to the surface because of the warmer water.
Pedosphere - More carbon in the northern latitude due to slower decomposition in the soils.
Cryosphere - Carbon stored in the polar areas and highland regions, in the Himalayas and Patagonia.
Atmosphere - Most carbons found over North America, Europe and Asia. More carbon found in colder winter months as trees photosynthesis less due to loss of leaves.
Biosphere - High concentration in Tropical Rainforests due to high density of vegetation.
134
# Define the factors driving change in the magnitude of the biosphere store?
```
Deforestation
Photosynthesis
Respiration
Combustion
Decomposition
```
Biosphere:
- Deforestation causes more trees to release carbon biosphere to atmosphere.
- Photosynthesis light energy converts carbon to glucose releasing oxygen into atmosphere.
- Respiration absorbs oxygen & releases carbon into atmosphere.
- Combustion releases carbon when burning items like wood.
- Decomposition of leaf litter and bacteria releasing carbon into atmosphere & pedosphere also forming HUMUS.
135
# Define the factors driving change in the magnitude of the hydrosphere store?
Diffusion
Calcification
Compaction
Phytoplankton
- Diffusion happens when ocean ventilates out carbon but also dissolves carbon in ocean acidification.
- Calcification is shells & coral absorb carbon ions & convert into carbonate to build shells.
- Compaction happens when marine plants and animals (fish) die and decompose on a sea bed, compacted under sediment to form hydrocarbons.
- Compaction also causes shells & coral to dissolve releasing carbon.
Phytoplankton - microscopic organism convert carbon via photosynthesis
136
Define the factors driving change in the magnitude of the cryosphere store?
Decomposition
- Very slow decomposition therefore lots of carbon stored in ice.
- But when melted releases lots of carbon into atmosphere.
137
# Define the factors driving change in the magnitude of the lithosphere store?
Hydrocarbons
Sedimentary rocks
Tectonic uplift
Weathering
- Hydrocarbons formed from organic matter (fish).
- Sedimentary rocks formed from inorganic matter, as shells & coral are compacted into rocks.
- Tectonic uplift is sedimentary rocks are revealed from the ocean.
- Weathering is the breakdown of rock in SITU.
- Carbon in the atmosphere mixes with water and creates carbonic acid which dissolves the rock into calcium ions which breaks off the rock and surface runoff transports this to the ocean.
138
Define how the carbon cycle changes over time due to natural variation for cold temperatures?
```
Low carbon dioxide levels every 100,000 years
Less transfer pedosphere
Less flow into the hydrosphere
Less decomposition
Less forest cover
More weathering
```
139
Define how the carbon cycle changes over time due to natural variation for hot temperatures?
More carbon every 100,000 years
| Melting of permafrost (Siberia) release of carbon and methane
140
Define how the carbon cycle changes over time due to natural variation for volcanic eruptions?
The heated rock recombines into silicate minerals, releasing carbon dioxide.
When volcanoes erupt, they vent the gas to the atmosphere and cover the land with fresh silicate rock to begin the cycle again. At present, volcanoes emit between 130 and 380 million metric tons of carbon dioxide per year.
542-251 million years more active
141
Define how the carbon cycle changes over time due to natural variation for wildfires?
Indonesia
Noticeable spike
Sink to source
142
Define 2 LAND USE CHANGES human factors affecting the carbon cycle?
Lots of urbanisation has caused more carbon to be produced and released into the atmosphere.
Transport, industry and cement production also entails large amounts of carbon being released into the atmosphere.
Urban - 2% land use but 97% of carbon
Cement - 2.4%-5% of global emissions
143
Define 3 factors of how deforestation affects the carbon cycle?
- Fewer trees, absorption of carbon is reduced.
- 13 million ha cut down each year which stops photosynthesis, respiration, combustion and decomposition from taking place.
144
Define 5 factors of how agriculture affects the carbon cycle?
- Fertilisers used are based on fossil fuels.
- Machinery emits lots of carbon.
- The movement to meat diets - emissions from animals up 11% (2001-11).
- Rice yields up 25% due to more carbon, but methane up 40%.
- 44% from Asia for the last 10 years
145
Define 2 human industries which affect the carbon cycle?
- Rice 10-20% - a staple for 50% of the world
| - Cattle in USA responsible for 20% of USA methane
146
Define how the carbon budget varies?
- No sphere in balance with any other.
- Hydrosphere, pedosphere & biosphere are main sinks.
- Lithosphere is main source.
- Greatest exchange of carbon between atmosphere and hydrosphere & biosphere.
- Atmosphere absorbs most amount of carbon followed by biosphere & hydrosphere.
- More carbon released than absorbed (budget not in dynamic equilibrium).
- Natural sources of carbon far greater than human sources, however, human sources are causing an increasing imbalance.
147
# Define the impact of the carbon cycle on the atmosphere?
Greenhouse effect & enhanced greenhouse effect
- Greenhouse effect & enhanced greenhouse effect:
Incoming short wave radiation (UV) heats earth & is absorbed into ground. Some UV is reflected by the clouds back to atmosphere. Earth’s surface radiates this heat out as longwave (infrared) radiation which heating air above it.
- Some longwave radiation escapes back to space whilst some is trapped by greenhouse gases e.g. CO2, methane, water vapour.
- Average temp of earth = 15℃, without the greenhouse effect it would be -18℃.
- The enhanced greenhouse effect is due to an increase in anthropogenic gases.
- An increase in these gases results in more longwave radiation becoming trapped, further increasing the temperature of the planet.
The balance between the incoming and outgoing radiation is called the radiative forcing
EVIDENCE:
16 of the top 17 hottest years on record have occurred since 2000.
Overall there has been an increase in global average temperature, since 1880 by around 1 degree.
Every month of the year is seeing an increase.
Comparison of CO2 levels and Antarctic temperatures for the last 800,000 years show a strong correlation.
FUTURE:
RCP (representative concentration pathways) predict between 450 and 1300ppm and 2 and 6 degrees by 2100
148
Define how the carbon cycle affects the albedo in the ocean?
- Fraction of sunlight that is reflected:
- Ice is around 0.9
- Open water is 0.1
- Ice melts causing decrease in albedo therefore water absorbs more short wave radiation.
- Amount of ice in Arctic dramatically decreased from 7 million Km2 in 1980 to 3 million in 2012.
- Oldest ice has seen a rapid decline.
- Ice melting leads to greater likelihood of potential resources being exploited which will lead to disagreements over territorial claims e.g Russia
149
Define how the carbon & water stores/cycles support life on earth?
Carbon:
- Essential for respiration & photosynthesis.
- Creation of shells & coral in oceans.
- 50% of biomass made of carbon.
- Provides energy e.g. hydrocarbons.
- Is a greenhouse gas keeping the atmosphere at habitable levels
Water:
- Needed by all living organisms.
- Vital source of power & energy production.
- Storage and cycling of these are vital and changes in the magnitude can have severe implications
150
# Define the roles that pos/neg feedbacks make within carbon & water cycles?
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Ocean Salinity
Albedo
Permafrost
Global Warming
Warmer Oceans
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- Ocean salinity - increase CO2 leading to warming ocean & melting ice leading to less saline water & possible collapse of thermohaline conveyor.
Albedo - increase in CO2 leading to warming ocean, therefore less ice & less albedo, therefore, more warming.
Permafrost - higher temperatures leads to melting therefore more CO2 and more warming.
Global warming - increase in temperature leads to more evaporation, therefore more water vapour (GHG) therefore more warming.
Warmer oceans lead to a reduction in the absorption of CO2.
TRF - see slides on this
151
# Define how do humans intervene in the carbon cycle to influence transfers and mitigate the impacts?
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Mitigation
Carbon Capture Storage
Good
Bad
Grasslands
Croplands
Forested land
Aviation Industry
Movement management
Flight management
Design & Tech
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Mitigation - attempts to slow down the process of global climate change, usually by lowering the level of greenhouse gases in the atmosphere.
Carbon Capture Storage (CCS) - converting CO2 into liquid under high pressure and transporting by ship or pipeline, storing it (sequestration) in depleted oil and gas fields several km below.
Good - capture 90%, forces out more oil and gas which would partly offset costs, traps the CO2, could also be stored in ocean.
Bad - forcing out more oil and gas just adds to problem, storing in ocean leads to acidification, very expensive - $800m Boundary Dam
Changing rural land use - ensuring carbon inputs are greater than losses.
Grasslands - adding manure and fertiliser increase soil organic carbon (SOC) and plant productivity. Avoiding overstocking of grazing animals.
Croplands - mulching to add organic matter and stop release of carbon, less ploughing, use of animal manure to increase plant productivity, rotation of crops and improved varieties.
Forested land - protection of forests, reforesting/afforestation, agroforestry.
Aviation industry - 2013 produced 700m tonnes of CO2 and by 2020 will be 70% higher and could be 300-700% higher by 2050.
Movement management - towing aircraft whilst still on ground, avoiding stacking, adopting fuel-efficient routes.
Flight management - 100% occupancy, cruising at lower speeds, matching aircraft to route.
Design and tech - increased efficiency, use of biofuels, improved aerodynamics, reduced weight, carbon capture with engines, maximising number of seats
152
Define how changes in the water and carbon cycle have changed the tropical rainforest?
- Average annual rainfall 2000mm and temp 27℃, as deforestation happens, atmosphere becomes less humid from reduced evapotranspiration.
- Fewer trees, most rainfall reaches ground immediately, compacting it & encouraging overland flow.
- Exposed to sun, soil becomes dry & vulnerable to erosion.
- Few trees remain, so little interception or evapotranspiration.
- Rates of runoff will increase, with an increased risk of flooding.
- Estimated that deforestation will affect places downwind, perhaps reducing rainfall by up to 20%.
- Half of the world’s rainforests have already been wiped out for commercial farming, mining, logging, settlements - often resulting in fires.
- Photosynthesis ceases and respiration drops.
- Rain washes ash into ground (increasing carbon content) and rivers.
- Decomposers largely absent.
- Replacing rainforest with crops etc reduces effectiveness of carbon cycle.
153
Define the relationships between the water, carbon cycle and the environment in the tropical rainforest?
- Absorb huge amounts of CO2 and 28% of world’s oxygen.
- Rainforests allow a considerable amount of water to be returned to the atmosphere through evapotranspiration.
- The canopy intercepts up to 75% of the rainfall, the other 25% is evaporated. Of this 75%, half is used by the plants and the other half either infiltrates into ground or runs-off to the river.
- Warm and wet climate ideal for plant growth, promoting photosynthesis and respiration.
- Wood is 50% carbon so a huge carbon store and sink.
- Decomposition is active due to climatic conditions.
154
# Define how human activity has affected the tropical rainforest?
Case study of Indonesia
Indonesia:
- 1960s - 80% rainforest but since has been massive deforestation.
- Demand for paper, pulp, plywood, palm oil and disputes over land rights.
- One of the highest rates in the world - under 50% remains.
- 1 million hectares cleared each year - 70% on mineral soils and 30% on peat.
- Peat once exposed is easily eroded by wind and rain. - Increased rates of decomposition turned into a source not a sink.
- Fire become more common as a quick way of clearing land for palm oil.
- Now the world’s 3rd largest emitter of greenhouse gases - 85% from rainforest and peatland loss.
- 1997-98 - huge fires, 8+million hectares burnt.
- Estimated that fires produce more CO2 than all the living things on earth remove from the atmosphere in one year.
155
Define the impacts of precipitation on drainage basin stores and transfers in a named river catchment?
River Exe, Exmoor, flows for around 80km to the sea at Exmouth:
- Water balance: precipitation (1295mm) = evaporation +/- soil water storage (451mm) + runoff (844mm) - therefore around 65% of precipitation runs-off - this is quite high, due to:
- Area - 600㎢, source in hills of Exmoor, flatter in the south.
Geology - over 80% is impermeable rocks e.g:
- Devonian sandstones
- Drainage ditches to drain peatlands reduce soil water storage
- High levels of precipitation
However, long lag time due to:
- Land use - Almost 70% grassland, 15% woodland and farmland. 3% peat bogs
156
Define factors affecting securing a sustainable water supply (and/or flooding) in a named catchment?
The River Exe catchment (Wimbleball Reservoir):
- 1979 River Haddeo, upland tributary, dammed to create Wimbleball Reservoir.
- Surface area of 150ha.
- Supplies water to Exeter & parts of East Devon.
- Regulates water flow, flattening the regime, reducing risk of flooding or drought.
- Peatland restoration on Exmoor - Exmoor Mires Project.
- Drainage ditches have been built in the past to make peat bogs suitable for farming. However, this has increased speed of water flow to the Exe and reduced water quality carrying more silt.
- As peat has dried out, decomposition has taken place, releasing CO2 and CH4.
- Peat has also been dug as fuel.
- The mires project has restored peat bogs (mires) by blocking drainage ditches - aim 2000ha.
- More water storage in upper catchments, ensuring steady supply of water through the year
Improved water quality - slower flow means less sediment carried to rivers, good for salmon.
- More carbon storage - water content increases and returns ground to saturated, boggy conditions. This helps to keep carbon in the peat.
- Improved opportunities for education, leisure, recreation.
- Improved grazing and water supply for animals.
157
Define the 3 types of precipitation?
- Frontal precipitation
- Orographic precipitation
- Convective precipitation
