Water and Carbon Flashcards
(90 cards)
1
Q
System
A
An assemblage of interrelated parts that work together by way of some driving force
Made up of elements - physical objects existing in the system
Attributes - characteristics of the elements that can be perceived and measured
Relationships - the associations between elements and attributes based on cause and effect
2
Q
Positive feedback
A
Effects of an action are amplified by secondary effects
3
Q
Negative feedback
A
Effects of an action are nullified by subsequent effects
4
Q
Hydrosphere
A
Water on the surface of the earth
5
Q
Cryosphere
A
Frozen water
6
Q
Lithosphere
A
Rock layers of the earth
7
Q
Biosphere
A
All life on earth - plants and animals
8
Q
Atmosphere
A
The air
9
Q
Atmospheric water
A
Water exists in all three states
Approximately 13,000km^3
0.001% of global water
10
Q
Terrestrial water
A
Water on land
Includes glaciers, freshawater, groundwater
0.9% of Earth’s water
0.03% is accessible
11
Q
Cryosphere water
A
Sea ice, ice shelf, permafrost
Ice caps cover less than 50000km^2, ice sheet if more
12
Q
Oceanic water and carbon
A
1.3billion km^3
72% of earths surface
Contains estimated 40000 GtC -2nd largest store
Carbon sink - 0.6 GtC/year
Absorbs ~40% of anthropically produced CO2
13
Q
Ice - water
A
Melting
14
Q
Water - ice
A
Freezing
15
Q
Ice - water vapour
A
Sublimation
16
Q
Water vapour - ice
A
Deposition
17
Q
Water vapour - water
A
Condensation
18
Q
Water - water vapour
A
Evaporation
19
Q
Surface tension
A
As a result of the hydrogen bond, water has very high surface tension, some creatures use this to move around the surface of a pond
20
Q
Latent heat
A
The sun’s rays do not have enough energy to evaporate the water so the water takes energy from the surroundings to supply it with enough energy to break the bonds.
Condensation - latent heat released by water molecules so warms environment
21
Q
Why do clouds form
A
Clouds form when warm air cools. This makes water vapour condense into water droplets and clouds. Water vapour gathers around condensation nuclei which are small particulates that the water can cling on to
22
Q
Frontal precipitation
A
Warm air is less dense than cool. When a warm air mass meet a cool air mass, the warm air rises which makes it cool down and condense.
23
Q
Orographic rainfall
A
When warm air meets mountains it is forced to rise. This cools it and it starts to condense. For example, Manchester and the Pennines
24
Q
Convective precipitation
A
Sun heats up the ground and water evaporates, as the air gets higher it condenses
25
Influence of precipitation and storms on water cycle
Big difference between antecedent levels and storm levels of precipitation will lead to vastly increased inputs → flooding
26
Influence of seasonal changes on water cycle
Winter - some water will freeze meaning it can no longer flow out of the system
Plants often die/lose leaves in Winter - reduce interception which increases surface run-off and increases water entering the river channel
27
Influence of vegetation on water cycle
The more vegetation, the more water is evapo-transpirated off the leaves reducing run-off and peak discharge
28
Influence of farming practices on water cycle
Ploughing breaks up the surface, more water can infiltrate.
Crops increase infiltration + interception, reducing run-off
Livestock trample the ground and compact it, decreasing infiltration + increasing run-off
SO depends what the farmland is used for
29
Influence of urban land use on water cycle
Construction of new buildings and roads create impermeable surfaces which massively increase run-off
30
Influence of deforestation on water cycle
Reduces amount of water intercepted by vegetation, dead plant matter on the floor also holds water. When it is removed the amount of infiltration decreases.
31
Influence of water abstraction on water cycle
Reduces water stores in lakes, rivers and reservoirs. This is prevalent in dry season.
32
Water Balance
Within a drainage basin, the balance between inputs and outputs is known as the water balance
Precipitation = overland flow + evapotranspiration + change in stores
Water surplus - precipitation is greater
Water deficit- precipitation is lower
33
Antecedent
Normal conditions before an event
34
Carbon
One of the most chemically versatile elements. It forms more compounds than any other element.
Needed by all plants and animals to survive
Primary source of carbon is the earth's interior, where it is stored in the mantle from when earth formed. It escapes at plate boundaries.
35
Forms of carbon within the carbon cycle
CO2 - gas in the atmosphere, soils and water
CH4 - gas in atmosphere, soils, ocean, and sedimentary rocks
Calcium Carbonate (CaCO3) - solid compound - white
Hydrocarbons - solids, liquids or gases usually in sedimentary rocks
Bio molecules - complex carbon compounds in living things e.g. proteins
The carbon cycle is a closed system
36
Organic carbon
In living things such as plants and animals.
37
Inorganic carbon
Non-living - sedimentary rocks
38
Global distribution of carbon
Carbon is most abundantly found just below the arctic circle and along the equator. For example, northern parts of Canada and Siberia. Places along the equator with abundant stores of carbon include the Amazon rainforest and Indonesia.
39
Main stores of carbon
Hydrosphere - dissolved CO2
Cryosphere - bubbles of CO2 trapped in ice
Atmosphere - CO2 + CH4
Biosphere - all living things
Lithosphere - marine and sedimentary rocks - 99%
Pedosphere (part of lithosphere) - soil - organic matter, broken down minerals
40
Carbon sink
A store that absorbs more carbon than it releases
41
Carbon source
Releases more carbon than it stores
42
GtC
Gigatonnes of carbon
43
Anthropogenic CO2
CO2 generated by human activity
44
Sequestration
Carbon locked in long term stores - e.g. sedimentary rocks
45
Stores/stocks
The total amount of carbon held within a part of a system
46
Fluxes
Measurements of the rate of flow of material between the stores
47
Processes
The physical mechanisms which drive the flux of material between stores
48
Weathering in the carbon cycle
Breakdown or decay of rocks, carbon stored in rocks, mainly as CaCO3. As the rocks break down, the carbon stored within is returned to the carbon cycle. When CO2 is absorbed by rainwater it forms carbonic acid which dissolves more carbon from rocks. This is then transported through the water cycle to the oceans
49
Burial and compaction - carbon
Organic matter dies and is buried and compacted by sediments and becomes compacted. Over millions of years these sediments from hydrocarbons like oil and coal.
50
Photosynthesis
Process whereby plants use light energy from the sun to produce glucose
CO2 + H20 → O2 + CH12 + O6
51
Respiration
Opposite of photosynthesis, consumers eat plants and convert it to energy
O2 + C6H12O6 → energy + H20 + CO2
52
Decomposition
When organisms die they are consumed by decomposers such as bacteria, fungi and earthworms. During this process of decomposition, carbon from their bodies is returned to the atmosphere in CO2
53
Combustion
Organic material contains carbon. When it is burned in the presence of oxygen it is converted into energy, CO2 and water
54
Geological sequestration
CO2 is captured at its source and injected as a liquid deep underground - this technique is still experimental. The ocean can absorb more additional carbon than terrestrial systems. Ocean sequestration also means the carbon sinks to great depths, meaning it can join the geological cycle
55
Terrestrial sequestration
Involves use of plants to capture CO2 from the atmosphere and stored in the stems and roots of the plants. Added benefits to local ecosystem, land based plants are slow growing and require monitoring. In this system the carbon is never permanently removed from the atmosphere
56
Volcanic activity in the carbon cycle
Releases gases when they erupt - magma made up of water vapour, CO2 and sulphur dioxide
Has little contribution to greenhouse effect
Sulphuric acid reflects radiation from the sun into space - albedo effect
57
Wildfires in the carbon cycle
Forests are a carbon sink so if they are burnt their carbon is released back into the air as CO2
Forest fires can be critical for new growth and rejuvenation - negative feedback
Human caused fires can threaten this balance
58
Fossil fuel combustion in the carbon cycle
90% of human-caused carbon released comes from combustion of fossil fuels. Vegetation and the ocean help to re-absorb 50% of this
2024 - China - 34%, USA - 12%, India - 7%
59
Agriculture in the carbon cycle
10% of carbon emissions
When soil is ploughed, air is mixed in with the soil, increasing microbial activity meaning more organic matter is decomposed
Enteric fermentation - methane belched by ruminant animals (cows and sheep) during digestion
Biological processes in rice paddies generate
60
Deforestation in the carbon cycle
CO2 emissions from land use change (mainly deforestation) account for 10% of human-based carbon emissions. Approx. 130,000 km^2 of forest cut down each year, mostly driven by need for agricultural land. Also logging, building roads, urban sprawl, wildfires.
1990-2005 - 3% of world's forest lost
61
Urban growth in the carbon cycle
Emissions from energy consumption has increased
21 most polluting cities release 10% of global emissions - expected to go to top 10
62
Carbon budgets
Global warming is fundamentally linked to the absolute concentration of greenhouse gases in the atmosphere. To stabilise global temperature at any level vs pre0industrial, then there is a finite amount of emissions that can be replaced before net emissions need to reach zero.
The overall outcome is to limit levels of CO2 so that temp. rise is limited to 2°C above pre-industrial levels. The global budget is 1000 PgC - 1 trillion tonnes.
63
Impacts of carbon cycle: Ocean acidification
Carbonic acid is produced when CO2 diffuses into the ocean, making it less alkaline -pH has dropped 0.1 since 1750 - carbonic acid reacts with carbonate to form bicarbonate, reducing the amount of carbonate ions which are needed for shells and corals (coral reefs provide food or livelihood for 500million people
On the other hand, the acidic water will be better at dissolving calcium carbonate rocks, meaning over time, the ocean will soak up more excess CO2
64
Impacts of carbon cycle: sea levels
Highly reflective ice is replaced by more absorbent water → ocean absorbs more solar radiation → temperatures increase → sea ice cover melts + shrinks → temperatures increase - positive feedback loop
Sea ice also provides a habitat for algae, so if it disappears there is disruptions to the food chain
Since the 1990s, sea levels have risen at a rate of 3.5mm/year
Warmer temperatures mean increased rate of ice melting in summer and reduced snowfall in Winter, resulting in an imbalance → net gain of water
Thermal expansion - when water heats up, it expands. 50% of the past century's rise in sea level is attributed to this
65
Impacts of carbon cycle: ocean salinity
↓ in salinity in deep North Atlantic:
- More freshwater being added to the ocean
- Slowing down of large scale oceanic circulation in the NE Atlantic
This leads to slower global heat transport which could lead to warmer water lingering in the north Atlantic, accelerating ice melt, and colder winters and hotter summers in North America, and less upwelling of nutrients from the seafloor
66
Impacts of carbon cycle: atmosphere
↑ atmospheric CO2:
Currently 400ppm, highest in 800,000 years
Up to 20% additional CO2 will remain in the atmosphere for millions of years
Enhanced greenhouse effect
Radiative forcing:
Energy is constantly flowing from the atmosphere in the form of sunlight - 30% reflected into space, 70% absorbed by earth. Increased CO2 in the atmosphere is changing the balance
67
Mitigation of climate change
Global → Individual
Reduce and prevent the emission of GHG to limit global warming
Global mitigation (countries work together to reduce emissions, Paris Agreement) → regional/national mitigation (government can reduce reliance on fossil fuels, improve public transport) → individual mitigation (use car less)
68
Adaptation to climate change
Drought-resistant crops – Farmers in sub-Saharan Africa are using crops like drought-tolerant maize to cope with reduced rainfall.
Green roofs and walls – Cities like Toronto and Copenhagen use vegetation on buildings to cool urban areas and absorb rainwater.
Mangrove restoration – Countries like Indonesia and Bangladesh are replanting mangroves to buffer storm surges and prevent coastal erosion.
Israel - advances in desalination and water recycling to address long-term water scarcity.
69
IPCC - Intergovernmental panel on Climate Change
The IPCC is an intergovernmental body of the UN. Its job is to advance scientific knowledge about anthropological climate change.
70
Carbon trading
The buying and selling of credits that permit a company to emit a certain amount of CO2 or other GHG
71
Rio Earth Summit
1992
UN conference developed an action plan for sustainable development that can be implemented on global, national, and local scales
72
Kyoto Protocol
1997
The first international treaty to become law. Over 170 countries agreed to reduce carbon emissions.
73
Copenhagen Accord
2009
World leaders met to tackle climate change. They pledged to reduce emissions by giving financial support to LICs/ No legally binding agreement
74
Paris Agreement
2015
17 sustainable development goals were developed by the UN general assembly for a more sustainable
75
Paris Agreement
2015
195 countries adopted first legally binding global climate deal in Paris
76
How do water and carbon cycles support life
Animals drink water
Fish live in water
Plants take in water through the roots
Water vapour
Ocean currents
Atmospheric circulation
All life is carbon based
GHG - CO2, CH4
Water is able to dissolve CO2
77
Carbon transfers on a plant scale
Tree:
Wood acts as a carbon store - 50% is carbon
Transfers:
- photosynthesis
- respiration
- decomposition
- combustion
78
Carbon transfers on a sere scale
Sere is a stage in the succession of vegetation in an ecosystem
The litho-sere is an example of terrestrial carbon cycling
Climatic climax community where environmental equilibrium is reached and succession stops
In the UK, this is deciduous wood
At a sere scale, the carbon cycle is more complex, involving numerous stores, and many transfers
79
Carbon transfers on a continental scale
Involves all the fast and slow carbon cycles
Relationships between stores are complex
Rate of transfers varies over time due to changing conditions on the planet
80
Physical pump
Continental scale cycling
Downwelling - saltier and colder water is denser and therefor sinks, taking carbon deep into the ocean
Thermohaline circulation - distributes carbon around the planet, cold water absorbs more CO2
Upwelling - winds and storms create upwelling currents which return carbon to the earth's surface
81
Biological cycle
Continental scale cycling
Sequesters carbon through photosynthesis by phytoplankton
As organisms die, they sink, taking the carbon down into the deep ocean
Decay of these organisms release CO2 into the water
82
Positive feedback - peat
Increased temperatures → warming wetland peat → bogs release methane → enhanced greenhouse effect → increased temperatures
83
Positive feedback - permafrost
Melting permafrost → release methane → enhanced greenhouse effect → increased temperatures
84
Carbon fertilisation
Increased CO2 available in the atmosphere results in more photosynthesis and plant growth
85
Permafrost
Covers 22% of the land surface and is defined as the sub-surface layer of the soils that remains frozen for 2 years
When it thaws, microbial activity restarts the decay of organic material
If 10% were to thaw, it would release enough CO2 for an additional 0.7C by 2100
86
Carbon budget in an ecosystem
The difference between the inputs of carbon and outputs.
Carbon source - releases more carbon than it can absorb
Carbon sink - absorbs more carbon than it releases
87
Soil water budget
The amount of water in the soil
Varies throughout the year:
Summer - rainfall falls so soil uses stored water - soil moisture utilisation
Afterwards - soil moisture levels are diminished so, when rain returns, soil moisture recharge. This is up to the field capacity where the soil can absorb no more water, and we are in a surplus
88
Eccentricity cycle
Every 100,000 years
Changes in the Earth's orbit caused by Jupiter and Saturn's gravitational pulls
89
Obliquity cycle
Every 40,000 years
Changes in the earth's tilt
21-24 degrees
Higher degree hotter weather
90
Axial precession
Every 25,000 years
Changes in the Earth's wobble caused by the tides
