earths life support systems Flashcards
(175 cards)
1
Q
what is a system
A
an interconnected series of flows and stores working together to create equilibrium
2
Q
define equilibrium
A
the average condition of a system, the system will be balanced
3
Q
what is an open system and give an example related to earths life support systems
A
can be influenced by external factors; energy and matter can enter and exit - local scale water cycles
4
Q
what is a closed system and give an example related to earths life support systems
A
it is self contained; energy can enter but matter cannot - global scale water and carbon cycles
5
Q
how is water important to supporting life on earth
A
- helps keep benign temperatures
- oceans absorb heat, store it and slowly release it
- clouds reflect solar radiation
- water vapour absorbs long wave radiation
6
Q
how is water important to flora and fauna
A
flora
- photosynthesis
- respiration
- transpiration
- reduce wilting
fauna
- keep hospitable temperatures
- bodily functions
7
Q
how is water important to humans
A
- industry
- sanitation and health
- food manufacturing / agriculture
- respiration / bodily functions
- leisure and recreation
8
Q
what are the three main stores and four main flows in the global water cycle
A
the atmosphere, oceans and land
precipitation, evapotranspiration, run off and ground water flow
9
Q
give examples of where water is stored in the water cycle
A
oceans
ice and glaciers
groundwater (aquifers)
lakes
soil
atmosphere
rivers
biosphere
10
Q
what is the percentage of global water stored in oceans, ice, groundwater, soil and atmosphere
A
oceans 97%
ice 2%
groundwater (aquifers) 0.7%
soil 0.005%
atmosphere 0.001%
11
Q
what is the water balance
A
shows the flows in a water basin over time, it states that precipitation is equal to evapotranspiration and stemflow plus or minus water entering or leaving storage
12
Q
what are the characteristics of precipitation as a flow into the water cycle
A
precipitation is water and ice that falls to the ground
- as rain, snow, hail, sleet, drizzle
- dependent on climate (high latitudes will be snow)
- depend on intensity (amount of precipitation in given time)
- depend on duration (how long precipitation event lasts)
- space - seasons differentiate between places
13
Q
what is the cause of precipitation
A
when tiny water droplets formed by condensation in saturated air grow until they are heavy enough to fall back to the ground
- through a process of coalescing (coming together to form one mass) as they collide
- or by ice crystals growing within clouds
14
Q
what is evaporation and transpiration
A
evaporation - the movement of surface water to the atmosphere
transpiration - the movement of water from plants to the atmosphere
15
Q
what are the factors effecting evapotranspiration
A
- temperature increases evaporation
- wind as it reduces humidity
- vegetation cover increases evapotranspiration as vegetation with low albedo (dark forests) absorb more solar radiation
- soil moisture content
16
Q
define the dew point
A
the temperature at which condensation occurs at because the air is no longer able to hold anymore water (becomes saturated
17
Q
what is condensation, when does it occur and what does this result in
A
the change of vapour to liquid water
- it occurs when air is cooled to its dew point and air is no longer able to hold anymore water
- clouds form through condensation in the atmosphere
18
Q
what are cumuliform clouds and when do they form
A
flat bases and vertical development
- form when air is heated locally through contact with earths surface
- this causes heated air parcels to rise freely through atmosphere, expand due to fall in pressure and cool
- reaches dew point and cloud form
19
Q
what are stratiform clouds and when do they form
A
layer clouds
- develop where the air mass moves horizontally over a cooler surface often the ocean
- also known as advection
20
Q
what are cirrus clouds and when do they form
A
wispy clouds
- form at high altitudes and consist of tiny ice crystals
- they don’t produce precipitation therefore little influence on water cycle
21
Q
what is fog
A
when water vapour condenses on or near the ground
- deposits a lot of moisture on vegetation and surfaces
22
Q
define convection
A
the vertical movement of air
23
Q
give four examples of where cooling can occur to allow clouds to form
A
- adiabatic expansion - heated air rises, pressure falls, air cools by expansion
- advection - air masses move horizontally over cooler surface
- air rises as it crosses a mountain barrier
- warm air mixes with cooler air
24
Q
what is a lapse rate
A
describes the vertical distribution of temperature in the lower atmosphere and the temperature changes that occur within an air parcel as it rises vertically away from the ground
25
what are the three types of lapse rates
environmental lapse rates (ELR)
dry adiabatic lapse rates (DALR)
saturated adiabatic lapse rates (SALR)
26
what are environmental lapse rates
the vertical temperature profile of the lower atmosphere at any given time
- on average temp falls by 6.5 degrees every KM of height gained
27
what are dry adiabatic lapse rates
the rate at which a saturated parcel of dry air ( less than 100% humidity so condensation isn't occurring) cools.
28
what is the average rate of cooling by adiabatic expansion
10 degrees/KM
29
what are saturated adiabatic lapse rates
the rate at which a saturated parcel of air (where condensation is occurring) cools as it rises through the atmosphere
30
define interception
where water is intercepted/ slowed down/ stopped by vegetation
31
what are some factors effecting the rate of interception
vegetation density - more dense = more interception
vegetation type - deciduous trees loose leaves = less interception
vegetation size - large trees will intercept more
32
what are the two types of run off processes
saturated overland flow
infiltration excess flow
33
what is saturated overland flow
when the pores in the soil fill with water and therefore becomes saturated and can't intake anymore water. this forces rainwater to run over the surface
34
what is infiltration excess flow
when the speed of rainfall is faster than the speed of infiltration and therefore soil can't infiltrate water fast enough. water will run over the surface
35
what are the five types of catchment hydrology
infiltration, throughflow, percolation, groundwater flow and cryosphere processes
36
what is infiltration
the vertical movement of rainwater through the soil
37
what is throughflow
water moving horizontally through the soil to stream and river channels
38
what are the factors effecting infiltration and throughflow
- precipitation intensity - infiltration decrease if intensity exceeds infiltration capacity as water will flow over the surface
- vegetation cover - roots help to break up the soil increasing infiltration
- soil and rock type - permeable rocks
- slope gradient - gradient increases more water will flow over the surface, reducing infiltration
39
what is percolation and what can this process create
the downward movement of water through permeable bed rock
- can create ground water storage and aquifers
40
the permeability of a rock is linked to two things, what are they
porosity - the volume of pore space
pervious - if rocks have joints or bedding planes that allow water to flow
41
what is ground water flow
the horizontal movement of water within aquifers ( underground) eventually emerging at the surface of springs
42
what is the cryosphere and what are the main stores and two unique flows that occur
cryosphere is where we have water stored in a solid state
- ice caps and glaciers are the main stores
- ablation and sublimation are the flows
43
what is ablation and how does this change temporally
melting of snow or ice to liquid state
- in summer melting occurs and therfore water volume increases
44
what is sublimation and how does this change spatially
water turns from a solid straight to a gas (water vapour)
- occurs more in places of high altitude or extreme latitudes such as the arctic
45
what are the three flows of energy in the water cycle that help water move between stores
solar energy, kinetic energy, gravitational energy
46
how does solar energy drive the water cycle
heat causes evaporation of water particles in air and from plants (transpiration). this evaporated water will condense to form water vapour and clouds leading to precipitation
47
how does kinetic energy drive the water cycle
helps to move water between stores. precipitation will hit the ground and flow (surface run off) until it reaches a groundwater store such as a river. this will use kinetic energy to move water to sea.
kinetic energy can be slowed due to interception
48
how does gravitational energy drive the water cycle
moves water down through the soil or rock
through soil - infiltration
through permeable rock - percolation
49
what does npp stand for and what is this
net primary productivity
- the amount of biomass produced minus the energy lost
- plant growth
50
how is carbon important to life on earth
life is built on large molecules of carbon atoms such as proteins, carbohydrates and nucleic acids
51
how is carbon important to humans
an economic resource - fossil fuels ( coal, oil and gas) are used to power the global economy
oil used as a raw material to manufacture products
- agriculturally, carbon is stored in crops - need to eat
52
briefly explain the history of carbon
- 3 billion years ago primitive bacteria photosynthesised absorbing co2
volcanic activity added co2, h2o and so2
- increase in co2 lead to more complex organisms
- co2 dissolving in oceans and stored in rock
- present cycle balance was established
- cycle begun to be altered by human activity
53
how many years ago was the present carbon cycle balance established
290 million years ago
54
give examples of where carbon is stored in the carbon cycle
the atmosphere, oceans, carbonate rocks, fossil fuels, plants and soils
55
give the amount of carbon stored in the following main stores:
atmosphere, oceans, carbonate rocks, fossil fuels, plants and soils
atmosphere 600 billion tonnes
oceans 38 billion tonnes
carbonate rocks 60000 - 100000000 billion tonnes
fossil fuels 4000 billion tonnes
plants 500 billion tonnes
soils 2000 billion tonnes
56
define sequestered
the taking in of carbon and storing it from the atmosphere. oceans, plants and soils sequester carbon
57
what is the slow carbon cycle and give an example of how carbon is stored in the slow carbon cycle
relates to the stores and flows or carbon that take a longer period of time to circulate
- formation of sedimentary rock
- fossil fuels
58
define diagenesis
the long term process where sediments are changed into sedimentary rock due to heat and pressure
59
how does sedimentary rock form
sediment ( for example grains of calcium from tiny creatures, cells, skeletons) dissolve under pressure ( pressure dissolution). at 100m diagenesis occurs where calcareous ooze cements sediment. at 1km there is enough pressure and heat to create sedimentary rock
60
what are some examples of sedimentary rock
limestone, chalk, sandstone
61
how is carbon released from the slow carbon cycle ( physical not human)
chemical weathering of rock
volcanic outgassing
62
how is carbon released by weathering
carbon is released from sedimentary rock. rain water with weak carbonic acid falls onto sedimentary rock, this then dissolves the rock ( carbonation)
releases carbon into rivers, ocean and atmosphere
63
how is the process of chemical weathering of sedimentary rock to release carbon accelerated
if the rock is covered by soil as it has a higher co2 concentration increasing the acidity of the rainwater
64
what are the main flows of carbon
precipitation
photosynthesis
rock weathering
respiration
decomposition
combustion
65
how is precipitation a flow of carbon
atmospheric co2 dissolves in rainwater to form weak carbonic acid
66
how is photosynthesis a flow of carbon
plants use co2 from atmosphere through process of photosynthesis to convert light energy to glucose to maintain growth and reproduction
67
what is the chemical equation for photosynthesis
6CO2 + 6H2O - C6H12O6 + 6O2
68
how is weathering a flow of carbon
- chemical weathering - carbonation
- physical weathering - freeze thaw
- biological weathering - chelation
69
define chelation
type of weathering caused by rainwater mixing with dead organic material in the soil forming acids
70
how is respiration a flow of carbon
plants and animals absorb oxygen which burns carbohydrates providing them with energy needed for metabolism and growth. this processes releases co2 back to the atmosphere
71
what is the chemical equation for respiration
C6H12O6+6O2 - 6CO2 + 6H2O
72
how is decomposition a flow of carbon and what can speed up this process of decomposition
decomposer organisms such as bacteria can break down dead organic matter releasing co2 to the atmosphere
- depend on climate
hot and humid = fast decomposition
cold = slow
73
how is combustion a flow of carbon
combustion occurs when organic material reacts or burns in the presence of oxygen, releasing co2
74
how is combustion helpful in terms of the carbon cycle - link to forests
wildfires benefit the health of ecosystems as it helps to clear little that has built up on forest floors during winter as there is less decomposition. increases biodiversity as it helps open the forest canopy
75
how is combustion unhelpful in terms of the carbon cycle
combustion as a result of human activities is releasing too much carbon from global stores. such as deliberately setting fires to clear land for farming and the combustion of fossil fuels for energy
76
give a figure for how much carbon is transferred a year to the atmosphere, oceans and biosphere from burning fossil fuels
10 GT of co2 a year
77
what are the two mechanisms that oceans use to take up carbon
physical pump and a biological pump
78
what is a physical pump
involves the mixing of surface and deep ocean waters by vertical currents, creating more distribution of carbon in the oceans
79
what is a biological pump
a process driven by marine organisms. phytoplankton (near the surface) combines sunlight, water and disolved co2 to produce organic material. carbon in the plankton either accumulates on the ocean floor or decomposes and released as co2.
80
what is upwelling and where does this most commonly occur
co2 coming to the surface as water is warmer and therefore rises, occurs near the equator
81
what is downwelling and where does this most commonly occur
co2 sinks as water is colder, occurs near the poles
82
how is carbon moved around the ocean - include long and short term stores
phytoplankton and under sea algae photosynthesises (short term store) , when this dies (along with zooplankton) the dead matter will sink to the floor. the sediment accumulates and gets buried (long term store). at 100m diagenesis occurs (long term) causing calcareous ooze which cements sediment. at 1km there is enough heat and pressure to from sedimentary rock
83
define diagenesis
a long term process where sediments are changed into sedimentary rock due to heat and pressure
84
what are some examples of sedimentary rock
limestone, chalk, sandstone
85
how can global warming impact carbon cycling in the ocean
- more carbon = more sediment
- change in ocean temp causes less upwelling and downwelling
- more thermohaline circulation when there is an increase in temp but also due to there being more water in the ocean there may be less salt as it dissolves
- photosynthesis increases because amount of co2 increases
-more co2 sequestration = more acidic = threaten to marine life
86
give three characteristics of healthy soil
- it will sequester carbon
- improve resilience to wetter weather as they are able to infiltrate and percolate therefore reducing floods and erosion
- provide water, air and nutrients for microorganisms and plants to thrive
87
what is the nutrient cycle
where nutrients are recycled and reutilised within an ecosystem. they are transferred between stores through various flows. They vary between different ecosystems
88
what are the four steps to the natural greenhouse gas effect
1 - solar radiation passes through atmosphere in short waves
2 - solar energy absorbed by earth's surface, warming it, more is absorbed by surfaces with lower albedo
3 - some infrared radiation is absorbed and reemitted by greenhouse gas molecules, warming up earths surface to sustain life
4 - some infrared radiation passes back through atmosphere and lost into space
89
define dynamic equilibrium
where natural systems like the carbon and water cycle achieve a state of balance over time. whilst there are various inputs, outputs and stores where short term fluctuations can be seen. the systems usually maintain stability
90
define a positive feedback loop
an initial change in a store or flow causes further changes to others, moving it away from initial balance
91
define a negative feedback loop
loops that work to restore balance when a flow or store has been strongly impacted
92
give an example of a positive feedback loop
burning fossil fuels - increases atmospheric store of carbon - which increases global temperatures - this thaws the tundra - methane is released - which increases global tempreture
93
give an example of a negative feedback loop
burning fossil fuels - release co2 - increases greenhouse gasses - increasing temperature - increasing photosynthesis - reducing co2 in the atmosphere - cooling the climate
94
what are the three land uses that can impact equilibrium
urbanisation, farming and forestry
95
how is urbanisation changing impacting equilibrium in the water cycle
the artificial surfaces ( roads, housing, factories ) are impermeable therefore no infiltration to soil or storage increasing run off. water flows quickly to streams leading to rapid discharge increasing river flow and flood risks.
urbanisation on floodplains also reduces water storage as water is normally stored in floodplains
96
how is urbanisation impacting equilibrium in the carbon cycle
reduction of greenspaces that would naturally sequester carbon from the atmosphere - increases carbon store in atmosphere. the population rely on fossil fuels, impacting the atmospheric store as well
97
are the impacts from urbanisation on the carbon and water cycles equilibrium's long term, short term, local, global
water - impermeable surfaces - has an immediate significance on a local scale
carbon - ff combustion - global long term scale
98
how does changing land use for farming impact the carbon cycle
- reduces carbon stores in biomass and in soils as crops are smaller than trees.
- soil stores reduced as soil is ploughed and carbon is exposed to oxidation releasing co2 to atmosphere.
- crops are harvested reducing biomass store
- harvesting before decomposition means little carbon is released back to soil
- soil erosion over time
- in LIDCS shifting cultivators are common causing poor soil health and further land use change
99
how can the impacts to the carbon cycle due to changing land for farming be exacerbated
if farmers use slash and burn to clear the forest as more co2 is released to the atmosphere, it is quicker and leaves a n nutrient rich layer of ash making soil fertile
100
how does changing land use for farming impact the water cycle
crops need to be irrigated, some water is stored in plants, some is evaporated and some is lost to soil storage. ploughing increases evaporation and soil moisture loss as water is exposed, furrows can be created increasing run off and erosion. heavy machinery can compact soil tightening soil pores and decreasing infiltration and increasing run off, increasing flood risks
101
how would farming cows alter the impact to the water and carbon cycle
not as much surface run off as not as much irrigation is needed but still more than forests ( 27 times) , carbon cycle more impacted as cows release methane, eat grass so soil is eroded quicker, cows compact the soil - less infiltration
102
how does planting trees ( forestry) impact the water cycle
- higher rates of rainfall interception in plantations in natural forests - in eastern England ( Sitka Spruces) interception rates are 60%
- increased evaporation a large proportion of intercepted water is stored in leaves surfaces of evaporated back to atmosphere
- reduced run off and stream discharge due to high evaporation and transpiration rates- conifer plantations usually reduce water yield to the public
- transpiration rates increase compared to moorlands - 350 mm a year
- clear felling causes temperate changes to the water cycle increasing run off and reducing evapotranspiration
103
how does planting trees ( forestry) impact the carbon cycle
- increase carbon stores - a plantation in the UK stores 170-200 tonnes of carbon = 10x higher than grassland and 20x higher than heathland
- trees sequester a lot of the carbon storing it for 100s of years - most is stored in the wood stem, forests only become a carbon sink for the first 100 years therefore the amount of co2 captured is balanced by inputs, outputs ands of litter and the release of co2 through respiration
104
what do we extract water for
drinking, leisure, hygiene, agriculture, HEP
105
where do we extract water from ( what are the two stores)
surface stores such as rivers and lakes
ground water stores such as aquifers
106
what case study is an example of extracting water from surface stores
the River Kennet
107
where is the river Kennet and what towns and cities rely on it as a water source
- in southern England
- drains an area of around 1200km2 in Wiltshire and Berkshire
- Swindon ( a population of 220000) rely on water for industry, agriculture and public use
108
how has the extraction of water in Kennet had an impact on the regional water cycle
- rates of ground water extracted have exceeded rates of discharge reducing flows by 10-14%
- during droughts in 2003 flows fell by 20% and droughts in 1990s caused them to fall by 40% - this meant there were less inputs and more outputs as farmers needed to extract more to irrigate
- lower flows have reduced flooding and temporary areas of standing water on wetlands and floodplains
- lower ground water levels have caused seepages to dry up and have reduced saturated overland flows on Marlborough downs
109
what is an aquifer and how are they normally created
a store of groundwater found in permeable or porous rock such as chalk or sandstone
created by percolation and ground water flows
110
what is a syncline and what are aquifers called if they are found at a syncline shape
a trough or fold of rock typically downward
- called an artesian aquifer
111
what is artesian pressure
where the permeable rock holding water will be under pressure from the rocks above and below, if a well or borehole were to be sunk into an artesian basin, the pressure would case the water to rise to the water table in a given location
112
what case study is an example of extracting water from ground water stores
The London Basin
113
how has the London artesian basin changed over time
- during 19th century the chalk aquifer had been exploited, at the peak abstraction of groundwater beneath London was 88 metres below sea level
- ground water was important to industry in 19th century
- water demand decreased and water levels recovered proposing threats to underground
- GARDIT gave out abstraction licences to help slow rising water and keep balance
114
what are fossil fuels
a natural fuel that is formed from anaerobic decomposition of dead organisms for example coal, oil and gas
115
what is crude oil, gas and coal formed from
crude oil and gas - dead marine organisms
coal - decomposition of plant material
116
give two properties of fossil fuels and what this means to the carbon cycle
finite and non renewable
- meaning they are part of the long term carbon cycle as they take a long time to form and are not easily replenished
117
where are gases mainly found
Mainly in the Northern Hemisphere, with Russia being a main country
118
where is coal mainly found
countries in Asia such as China
Australia also provide
119
where is oil mainly produced
USA produce the most oil with Russia not being too far behind
120
how has fossil fuel combustion changed over space and time for China and the USA
China - when they joined the UN, they became more connected and had better technology, therefore using more fossil fuels. They joined the World Wide trade organisation where they encouraged investment and outsourced factories. - now is world top emitter
USA - World War 2 increased their manufacturing of machinery therefore increasing combustion
121
how has fossil fuel combustion changed over time for the United Kingdom and Kenya
United Kingdom - the industrial revolution saw UK as the largest global emitter of co2 due to burning coal until 1890
Kenya - very low emission but still pledged to reduce their emissions by 30% by 2030 - shows how developing countries can develop without using fossil fuels.
122
discuss which stores and flows are most impacted by the increase of fossil fuel combustion
lithosphere is mostly impacted
- huge scale therefore huge worldwide impact
- not resilient as the fossil fuels being extracted are finite and non renewable
- long term impact as the lithosphere store is decreasing
atmospheric is also impacted a lot
- a huge store and is a direct impact
- impacts other stores and flows
- which is an immediate impact
123
discuss which stores and flows are least impacted by increase of fossil fuel combustion
volcanic outgassing
- not directly impacted there is no relationship between them
weathering - does increase weathering risk which is a direct consequence however it is a very small flow
124
give five examples of renewable energy resources
solar energy, geothermal, wind, HEP, bioenergy
125
what is meant by carbon capture storage
technology that can capture a lot of the worlds co2 emmisions
126
what are the three stages of carbon capture storage
- co2 is separated from power stations emissions
- it is compressed and transported by pipeline
- it is then injected into porous rock deep underground, where it is safely stored
127
what does a Milankovitch cycle and what is the difference between an elliptical orbit and a circular orbit
the shape of the orbit around the sun
elliptical orbit helps explain periods of cooling that create glacial periods and circular orbits create interglacial periods
128
how do changes to the orbital cycle impact stores and flows of carbon
- increased ice cover cause atmospheric co2 levels to decrease at the start of ice ages
- as ice cover increases, sea levels fall exposing large areas of land allowing growing vegetation to intake more co2
- colder oceans dissolves more co2
- ice glaciers grind up rock = more nutrients to ocean life = more carbon in deep ocean
- sea ice covers areas of upwelling = less co2 back to atmosphere
- increased phytoplankton growth = less co2 in atmosphere = more cooling
129
how do changes to the orbital cycle impact stores and flows of water
- water is transferred from ocean store to ice store, glaciers and permafrost
- sea levels fall by over 100m and ice expands to cover continental land mass
- ice shifts destroying tracks of forest meaning the water in the biosphere shrinks
- lower evapotranspiration as lower precipitation and less plant storage of water as ground is frozen = less exchange of water to atmosphere, oceans and soil
130
define global warming
the rise in global temperatures due to mainly increased concentration of greenhouse gases in atmosphere
131
define climate chage
the long term change in climate including precipitation, temperature, humidity and wind patterns, often having knock on effects
132
define anthropogenic
environmental change caused or influenced by people, either directly or indirectly
133
define a short term change and define diurnal
from hourly to seasonal changes - anything under a year
diurnal - changes that occur throughout the day
134
describe diurnal changes to the water cycle in a temperate climate
- lower temperatures at night reduce evaporation and transpiration
- convectional precipitation is dependent on heat from the sun heating surface stores
135
describe diurnal changes to the carbon cycle in a temperate climate
- during daytime co2 flows to atmosphere to vegetation through photosynthesis, but this is reversed at night where there is no sunlight, loosing co2 to atmosphere.
same with phytoplankton in plants
136
describe the changes to the water cycle in spring
water - increase temperature - increased evapotranspiration rates
- precipitation increased due to high rising temperature and cold nights for condensation
- soil saturated from winter = saturated overland flow
- interception begins to increase
137
describe changes to the carbon cycle in spring
- increased photosynthesis and temperature warms so there are more plants
- atmosphere store begins to decrease due to more photosynthesis
- soil stores decrease due to plants
138
describe changes to the water cycle in summer
- plants uptake water faster
- high evaporation and transpiration
- surface stores at lowest point
- low condensation and high evaporation = high humidity
- limited rainfall = poor soil quality = more run off = flooding
139
describe changes to the carbon cycle in summer
- co2 stored in atmosphere is deceased
- biomass store at its highest
-largest flow of photosynthesis as more plants and heat.
- soil store decreases as plant uptake is high therefore limited decomposition
140
describe changes to the water cycle in autumn
- interception decreases as leaves fall
- rainfall increases as high temps drop at night = more condensation
- surface stores of water increase
- soil becomes saturated = more run off
- groundwater recharge occurs
141
describe changes to the carbon cycle in autumn
- decomposition increases as deciduous leaves start to drop
- photosynthesis will decrease and respiration will increase as temps drop
- biomass stores decrease and atmospheric stores increase
142
describe changes to the water cycle in winter
- mass precipitation due to cool temperature and a lot of condensation
- freezing of water
- less interception and evapotranspiration
- less plant growth due to minimal soil moisture
- very slow cycle
143
describe changes to the carbon cycle in winter
- sunlight hours are lower so less photosynthesis
- during later months less decomposition due to snow, earlier winter more decomposition
- greater carbon stored in ice but this fluctuates more in temperate
- lower NPP due to no plant growth
144
how can changes to the cycles be monitered over time
- arctic sea ice
- sea surface temperatures
- water vapour
- deforestation
- atmospheric co2
145
how do the carbon and water cycle interact
- directly when carbon is transported in solution by rivers and oceans
- ecosystems function simultaneously as stores of water and carbon influence flows of both
-deforestation lead to increased overland flow which causes soil erosion and loss of soil storage of carbon
- water stores hold carbon, water flows can transport carbon
- increase carbon in atmosphere changes global climate
146
how do the carbon and water cycle have interdependency in the atmosphere
- to maintain heat by the greenhouse gas effect
- both carbon dioxide, methane and water vapour absorb heat keeping planet warm and regulating the carbon and water cycle
147
what stores and flows of water can be facilitated by vegetation and soil
interception, evapotranspiration, soil storage, surface run off (saturated overland flow and infiltration excesses overland flow), plant uptake, infiltration, flowthrough
148
what stores and flows of carbon can be facilitated by vegetation and soil
decomposition, photosynthesis, respiration, vegetation, soil, litter, plant uptake
149
how does the availability of water impact carbon flows and stores
photosynthesis rates
NPP
input of organic litter to soils
150
complete a feedback loop involving carbon and water cycles interaction with vegetation and soils starting with reduced vegetation meaning less sequestration to biosphere and lower soil carbon
- this reduces carbon in soils causing infiltration to slow down meaning infiltration overland flow is more likely - more surface run off will increase leaching meaning soil store of carbon will decrease further - with poorer soil there will be less vegetation and reduced sequestration.
151
how are carbon and water interdependent in the ocean
atmosphere warms due to more atmospheric co2, warmer ocean warms ocean surface which can increase evaporation rates, sequestration of less co2 warming it further, warming may lead to more ocean currents, disrupting natural habitats, declining ecosystem productivity and less photosynthesis = atmosphere warms further. this may lead to the oceans increasing sequestration to more back to equilibrium, meaning oceans become more acidic as they take in more co2, acidity bleaches coral threatening marine life, disrupting natural habitats, more co2 in atmosphere
152
how do the carbon and water cycle have interdependence in the cryosphere
carbon is trapped in ice store, regulating carbon cycle, co2 levels in atmosphere determine intensity of GHG and therefore more permafrost and ice melt. water melting lowers albedo meaning more solar radiation is absorbed, temperatures warm further. melting permafrost exposes organic material to oxidation and decomposition released co2 and methane
153
write a positive feedback loop involving the carbon and water cycle in the cryosphere starting with increased levels of c02 in atmosphere
- lead to enhanced greenhouse affect and higher global temperatures, increased absorption of solar radiation raises temperatures further, this causes increased rates of melting ice sheets, permafrost and sea ice. melting also exposes land and sea surfaces which leads to lower albedo, this decreases frozen water storage increasing run off and river flows and evapotranspiration, which releases more co2 and methane
154
why is demand for water increasing
- agriculture is the main reason, industry and domestic use
- growing population, more food production and energy
- more urbanisation which means more is needed for industry, it also changes the flows and stores as there is more impermeable surfaces. water is also spatially concentrated.
- there is also a higher demand of consumption in developing countries for meat and machine energy
155
why is supply for water falling
1/10 of 1% of water is available for humans
droughts, floods and storms are increasing which causes less water usage as water is changed where it is stored and it pollutes more water, this is due to climate change
156
what is the name of the town that was approaching drought day zero
cape town
157
what were the causes for the droughts in cape town
- three consecutive years of extremely low rainfall
- climate change due to an increase in greenhouse gas emissions
158
what was water usage like in cape town before and after the restrictions were implemented
- demand has been reduced from 1200 million litres a day to less than 600 million litres in one day
- requires residents to use less than 50 litres of water a day compared to the 300 litres it was before
159
what are the long term impacts of water insecurity in cape town
- general population has better understanding of linkage between day to day life and climate
- improved their mentality on saving water and the value of water
- working on long term measures such as desalination plants
- increases research and investment into alternate water sources.
160
what are the four human causes of water insecurity
growing population and improved living standards, increasing agricultural demand, over abstraction, contamination
161
how is growing population and improved living standards causing water insecurity
-population growth in urban places along with increased middle class population leads to more unsustainable water use in places already venerable
- larger homes, motor vehicles and high energy consuming devices are increasing
- 2.5 billion people depend on ground water to satisfy their basic needs
-increase in global water demand is predicted to be 55% up by 2050
162
how is increasing agricultural demand causing water insecurity
- agriculture is the largest human activity using water =70% globally and space specific 90% in developing
- inefficient use of water for crop production depletes aquifers, reduces river flows and degrades wildlife habitats
- hundreds of millions of farmers rely on groundwater to ensure food security and jobs
163
how is over abstraction causing water insecurity
- this occurs when too much water is removed from ground water stores so supplies diminish
- 20% of the words aquifers are over exploited
- most over extraction is for intensive farming which is the largest human activity using water
164
how is contamination causing water insecurity
- intensive agriculture and the use of chemical fertilisers and pesticides contaminating water
- industrial production - lead to waste and chemicals contaminating water
- mining - dangerous metals contaminating water
- untreated sewage - bacteria contaminating water
- urban run off
- causes threats to health
- 1/2 of all rivers are badly polluted
165
what is brackish water
water that is 1/2 salty and 1/2 fresh
166
what is salt water encroachment
the natural movement of saline water into fresh aquifers
167
why does salt water encroachment happen
- global sea rising due to melting of ice and thermal expansion lead to an increase in volume - enable sea water to intrude further inland
- increased localised abstraction of groundwater
- extensive groundwater pumping allows salt water to move into aquifers to then be extracted
168
what are the impacts of salt water encroachment
- less fresh water for consumption
- threatening farming and ecosystems
169
how have humans increased the natural process of salt water encroachment
over abstraction of water due to an increased population therefore an increase in water demand. also enhanced greenhouse effect.
170
what is Kuznets curve
171
define mitigation
returning to equilibrium. strategies that aim to reverse or change stores and flows before the tipping point occurs
172
define adaption
trying to reduce the vulnerability to events by changing your way of life rather than changing the hazard itself
173
define sustainability
meeting the needs of the present without compromising for the future
174
what are the 6 ways of managing the carbon cycle (rank them in order of most effective to least)
- afforestation
- agricultural
- carbon capture
- wetland restoration
- international agreements
- cap and trade
175
what are the 6 ways of managing the water cycle ( rank them in order of most effective to least)
- desalination
- forestry
- rainwater harvesting
- water allocating
- drainage basin planning
