Paper 1 — Section C — Carbon Cycle Flashcards
1
Q
What is the carbon cycle?
A
Movement of carbon between stores in the lithosphere, hydrosphere, biosphere and the atmosphere
It is a closed system as a whole, with subsystems that are open and have inputs + outputs
2
Q
Define closed system
A
There are no external inputs or outputs of carbon to the earth so the total amount of carbon is fixed and finite
3
Q
Define stores
A
Huge reservoirs where carbon is held. AKA known as pools, stocks and reservoirs
They function as sources and sinks
4
Q
Define sources
A
Add carbon to the atmosphere
5
Q
Define sinks
A
Remove carbon from the atmosphere
6
Q
Define fluxes
A
Movement of carbon between stores from one store to another. AKA flows. They provide the motion in the carbon cycle
7
Q
Define processes
A
Physical mechanisms which drive the fluxes between stores
8
Q
Define reservoir turnover
A
Rate at which carbon enters and leaves a store, measured by the mass of a store divided by the fluxes
9
Q
What are the 4 main carbon stores?
A
- Atmosphere
Gases i.e carbon dioxide and methane - Hydrosphere
Oceans, lakes, rivers etc which dissolve CO2 - Lithosphere
Carbonates found in rocks i.e limestone and chalk and fossil fuels - Biosphere
Living and dead organisms, most notably the worlds forests
10
Q
What are the top 3 biomes with the most carbon stored?
A
- boreal forests
- tropical forests
- tropical savannahs
11
Q
What are the stages during limestone formation, and how does limestone get eroded / transfer carbon for deposition on the seabed?
A
- Skeletons of marine creatures and formed marine phytoplankton absorb carbon through photosynthesis
- The remains accumulate on the seabed and compact into limestone over time
- *Limestone may also form from precipitation of calcium carbonate from salt, freshwater or evaporation of seawater
- Limestone rocks are vulnerable to chemical weathering (acid rain)
— weak carbonic acid dissolves the calcium carbonate - Erosion processes transfer dissolved carbon for deposition on the seabed
12
Q
How long ago was most coal formed?
A
300-360 million years ago
13
Q
How does peat form?
A
Where partial decomposition takes place: remains of plants receive no oxygen underwater. This incomplete destruction leads to the accumulation of peat
14
Q
What is peat?
A
A fibrous, soft, spongy substance in which plants are easily recognisable. Contains large amounts of water (must be dried before use)
Therefore seldom used as heat source
15
Q
What is lignite?
A
It is dark brown in colour and contains traces of plants like peat.
Found in many places but is only used when more efficient fuel isn’t available.
16
Q
How is lignite formed?
A
Lignite forms when peat is subjected to increased vertical pressure from accumulating sediments
17
Q
What happens when excess pressure is applied to lignite?
A
Further compaction and virtually all traces of plant life disappear to form bituminous coal
18
Q
What is the order of stages before coal formation?
A
- Peat
- Lignite
- Bituminous, soft coal
- Anthracite
19
Q
How old is oil / natural gas?
A
250-260 million years old
20
Q
What did oil originate from millions of years ago?
A
Microscopic plants and animals living in the oceans.
These organisms absorbed energy from the sun, which was stored as carbon molecules in their bodies
21
Q
What does higher pressure / temperature create compared to lower pressure / temp? (Think of non-renewables)
A
Natural gas versus lighter oil
22
Q
What has caused the pockets and deposits of oil and gas in the earths lithosphere?
A
Tectonic Earth movements resulting from tectonic folding and faulting adjusted the relative positions of different layers of rock
Some fossil fuel deposits got trapped under impermeable rock layers (where we find them today)
23
Q
How long will our current oil and natural gas reserves last?
A
60-90 years
24
Q
Describe the 4 stages of chemical weathering (rainwater)
A
- During precipitation, rain falls to the ground and absorbs CO2
- This then makes it acidic (carbonic acid)
- Precipitation then reacts with calcium carbonate within limestone / chalk
- Finally, CO2 gets released back into the atmosphere, or calcium carbonate is transported by rivers back into oceans
25
Define volcanic outgassing
Where eruptions spewed gases from the Earths interior into the atmosphere
26
Describe the 3 stage process of volcanic outgassing
1. Sedimentary rocks get formed
2. These then move towards a convergent plate boundary over time
3. The rock then gets subducted and CO2 gets released during CO2 eruptions
27
Where does volcanic outgassing occur?
- active or passive volcanic zone associated with tectonic plate boundaries
* divergent boundary volcanoes emit less CO2 because lava is basic (contains less gas)
- places with no current tectonic activity I.e hot springs and geysers
- direct emissions from fractures in the Earths crust
28
Describe the negative feedback loop regarding the regulation of the geological carbon cycle
1. Increase in volcanic activity
2. Rise in CO2 emissions and loss of carbon from rocks
3. Temperature rises
4. More uplift of air, condensation and rain
5. More chemical weathering and erosion of rocks
6. More ions deposited on ocean floors
7. More carbon stored in rocks
-back to 1-
29
Define carbon sequestration
It is the process of capturing and storing atmospheric CO2 in plants, soils, oceans and geologic formations
30
What is a physical carbon pump?
It is a process which operates in oceans to circulate and store carbon
(Thermohaline circulation)
31
What is a biological carbon pump
The transfer of CO2 to marine organisms (phytoplankton) via photosynthesis, as they respire they consume carbon and release oxygen in the process
Most of the carbon dioxide taken up by phytoplankton is recycled near the surface. About 30% sinks into deeper waters before being converted back into carbon dioxide by marine bacteria.
32
1 peta-gram is worth how much carbon in grams?
1 billion
33
Which biome stores the most carbon?
Boreal (pine) forests
34
Name the 3 stores of carbon
1. Terrestrial (lithosphere)
2. Hydrosphere
3. Atmosphere
35
Ocean sequestration: how much carbon do oceans store?
(Worlds largest carbon store)
- 50x greater than the atmosphere
- 93% stored in undersea algae, plants, coral
- 38,000-40,000bn metric tonnes in CO2 in the ocean itself
- 66-100mn-bn in marine life
36
What is the thermohaline circulation?
The component of general oceanic circulation which is controlled by horizontal differences in the temperature and salinity gradient
37
(Physical pump) Describe the stages of the thermohaline circulation, mentioning how it stores and releases carbon
1. Water in polar regions is colder and more saline, therefore denser than in the tropics.
2. As a result of this, it sinks (downwelling) to the seabed, where dissolved carbon dioxide moves in slow-moving, deep currents for hundreds of years (carbon store)
3. The cold sinking water draws in the warmer water from the oceans surface above (draws water across surface from the tropics)
4. This movement of water from the tropics then draws cold water up (upwelling) from the seabed to be warmed again — as it rises towards the surface, dissolved CO2 is released back into the atmosphere
38
(Biological pump) Which organisms sequester CO2?
Phytoplankton
39
(Biological pump) Where are phytoplankton typically found and why?
They float near the ocean surface to access sunlight for photosynthesis
Before sinking deeper into the ocean through the carbonate pump and action of the thermohaline circulation
40
(Biological pump) How much carbon do phytoplankton sequester each year?
2 billion metric tonnes
41
What are the 3 pump categories?
1. Biological pumps
2. Carbonate pumps
3. Physical pumps
42
(Physical pump) What does warm water do to CO2?
Release it
43
(Physical pump) what does cold water do to CO2?
Absorbs it
44
(Carbonate pump) what do marine organisms use calcium carbonate for?
To form outer shells / skeletons I.e plankton, coral, oysters
45
What is terrestrial sequestration?
Where primary consumers eat the primary producers i.e bugs, beetles and herbivores (sequestered carbon passes on, becoming a part of their fats and proteins after digestion)
In turn, biological decomposers I.e worms, bacteria, insects feed on dead plants / animals and then release carbon back into the atmosphere through respiration
46
Where can biological carbon be stored?
In soils in the form of dead organic matter (quicker process in tropical soils, slower process in tundra)
Alternatively
Returning it to the atmosphere due to decomposition over several years
47
Why don’t soil stores develop in rainforests?
Rainforest soil is thin and infertile due to the humidity
As litter and dead wood decay, they are recycled so quickly that a soil store doesn’t develop
48
How much CO2 does the rainforest absorb and how much earth do they cover?
They account for 30% and only cover 17% of the earths surface
49
Why do plants sequester more carbon in the summer?
They have more leaves and so more carbon can be sequestered
50
Do CO2 levels rise or fall in summer months?
Rise
51
Define what a green plant is
Primary producers which use solar energy to create biomass
52
How much more carbon is sequestered than released?
1000x more
53
What is a carbonate carbon pump?
A process where sediment gets formed from dead organisms that fall to the ocean floor, especially their shells which are all rich in calcium carbonate
— this carbon becomes part of deep ocean currents or compact and form limestone
54
What are the 2 types of greenhouse effect
1. Natural greenhouse effect
2. Enhanced greenhouse effect
55
Define the natural greenhouse effect
The natural process whereby the earths surface warms up at a sustained rate
56
Define the enhanced greenhouse effect
The natural greenhouse gas process which has gotten exacerbated by anthropogenic (human) activities
57
Name some human factors which have contributed towards the enhanced greenhouse effect
- burning of fossil fuels
- jet aircraft engines
- fertilisers and pesticides
- cattle farming
- solvents and cooling equipment
- deforestation
58
Describe the 4 stages of the natural greenhouse effect
1. Short-wave radiation passes through the atmosphere
2. Some short-wave radiation is absorbed and converted into long-wave radiation
3. Some long-wave radiation is absorbed and re-emitted, heating up the earths mean temperature
4. Some long-wave radiation is reflected and passes back into space
59
Name the 6 greenhouse gases
1. Nitrous oxide
2. Halocarbon
3+4. Ozone + water vapour
5. Methane
6. Carbon dioxide
60
What is the most common greenhouse gas? (What%?)
CO2 - 89%
61
Why are greenhouse gases important?
They absorb and reflect back into the atmosphere some of the radiated heat — earth 16°C warmer because of them
62
Since when has the concentration of greenhouse gases increased by 25%?
1759 — industrial revolution
Since 1980s, 75% of CO2 emissions have come from the burning of fossil fuels
63
Where on the Earth are sun rays their strongest?
The equator
64
Where is solar radiation more dispersed / covers a larger area?
The poles
65
What colour terrain absorbs, and which reflects heat
Absorbs — black
Reflects — white
66
Which continents receive the highest rainfall?
South America, North America, Europe
67
Which continents recieve the least rainfall?
Middle East, Northern Africa
68
What is a climate feedback loop?
Knock on effect which feeds back into our climate (either +ve or -ve)
69
What is a negative feedback loop? (Climate change) + provide examples
Impact which offsets the prevailing change in climate.
Under global warming, this would create a cooling effect, balancing out the changes
I.e afforestation, less fossil fuels
70
What is a positive feedback loop? (Climate change)
Impact which increases the change in the climate.
Adds to global warming by creating further heating
I.e warming temps in arctic
71
How does weathering of rocks release carbon into the atmosphere?
Rocks on the land are broken down by carbonation weathering (when CO2 in the air mixes with rainwater to create carbonic acid — this aids erosion of rocks I.e limestone
This carbon is moved through the water cycle and enters oceans before being used by marine organisms to make their shells
72
How does the concentration of atmospheric carbon influence the natural greenhouse effect?
CO2 controls the amount of water vapour in the atmosphere and therefore the size of the greenhouse effect — as concentrations of CO2 rise, air temperatures go up and more water evaporates into the atmosphere which amplifies the greenhouse effect
73
What unit is used to measure the carbon fluxes between carbon stores?
Petagrams or gigatonnes of carbon annually
74
Which of the 4 is the largest carbon store?
Geological: over 100 million Pg of carbon in the lithosphere
75
How are sedimentary rocks formed? 4 steps
1. Sediment is deposited in layers in a low-energy environment i.e seabed
2. Further layers are deposited and sediment undergoes diagenesis
3. Lower layers become compressed and chemical reactions cement particles together
4. Lithification occurs
76
Define lithification
The conversion of loose, unconsolidated sediment into solid rock
77
Define diagenesis
Physical and chemical changes that occur during the conversion of sediment to sedimentary rock
78
Provide some characteristics about limestone rock / its relation with carbon / how is it formed?
- composed of calcium carbonate: 40% is carbon by weight
- 80% of lithospheric carbon is found in limestone
- limestone is formed when calcium carbonate is deposited on the ocean floor
79
Which physical landform forms one of the earths largest carbon stores, and why?
Himalayas:
These mountains originated as ocean sediments rich in calcium carbonate derived from crustaceans
These sediments have since been up folded, and eventually it’s carbon has been eroded and transported back to oceans
80
How can geological carbon be released into the atmosphere through acid rain?
CO2 in the atmosphere reacts with moisture to form weak carbonic acid. This reacts with surface minerals when raining, and slowly dissolves them
81
What does soil health often depend on?
The amount of organic carbon stored in the soil. The storage amount is determined by the balance between soils inputs and outputs
82
How can only a small amount of surface soil erosion have such a devastating impact on soil health / fertility?
Carbon is the main component of soil organic matter
> helps give soil its moisture-retention capacity, it’s structure and fertility
Healthy soil has a large surface reservoir of available nutrients which condition the productivity of ecosystems
83
What percentage of CO2 emissions are estimated to be remaining in the atmosphere since the Industrial Revolution?
50%!
84
What has the impact of additional CO2 being added to the atmosphere meant for the atmosphere? (Climate change)
- rise in global mean temperatures
- more precipitation / evaporation
- sudden shifts in weather patterns
- more extreme weather events
- some areas becoming wetter, some becoming drier
85
What do the implications of climate change mean for ecosystems?
- rising sea levels; increased glacial meltwater etc which threatens coastal cities
- decline in yield from ecosystems; decline in biodiversity, changes in dist. Of species, marine organisms threatened etc (coral bleaching)
86
What are the implications of global warming for the hydrological cycle?
Increased temperatures and evaporation rates which cause more moisture to circulate around the cycle
87
How do biological pumps circulate and store carbon?
- Phytoplankton and crustaceans absorb co2 into their shells
> essentially converts co2 into food for predators
- most of this co2 gets recycled near the surface, but 30% sinks deeper into waters before being converted back into co2 by marine bacteria
88
What is the bio-geochemical carbon cycle?
Processes occurring in the soil, water and atmosphere that are biological and chemical
89
How does the biological carbon pump reduce global warming? (think CO2 levels)
It keeps atmospheric CO2 levels at 200ppm lower than they would be without it
> reduces global warming
90
On what 2 timescales can carbon fluxes within ecosystems occur?
1. **Diurnally;**
During the day, fluxes are positive from the atmosphere into the ecosystem: plants are respiring — the reverse occurs at night when respiration occurs but not photosynthesis
2. **Seasonally;**
During winter CO2 concentrations increase because of low levels of plant growth: leaves don’t absorb CO2 — when spring arrives more plants = lower concentrations
91
What conditions determine the amount of carbon stored within soils? (Terrestrial stores)
1. **Climate:**
Dictates the rate of plant growth and decomposition — increases with higher temps and rainfall
2. **Vegetation cover:**
Affects the supply of dead organic matter — heaviest in tropical areas
3. **Soil type:**
Clay protects carbon from decomposition — clay-rich soils have higher amounts
4. **Land use:**
Cultivation and other forms of soil disturbance increase the rate of carbon loss
92
What is the key role of terrestrial and ocean photosynthesis in regulating CO2 levels?
keeping carbon dioxide levels relatively constant — helps to regulate the earths temperatures
93
What are domestic energy sources?
Energy that is sourced and supplied in the same country
94
What are overseas energy sources?
Energy which is sourced overseas and imported
95
What are primary energy sources?
An energy form found in nature that hasn’t been subjected to human engineered conversion processes
96
What are secondary energy sources?
They are derived from the transformation of primary energy sources
97
What is energy security?
This is achieved when there is an uninterrupted availability of energy at a national level and at an affordable price
98
What are 4 key aspects of energy security?
1. **Availability** — suitable climate? (solar panels etc), high supplies from exporters
2. **Accessibility** — are there nearby reserves?
3. **Affordability** — competitively priced: are costs passed onto consumers who can’t afford them? Unsustainable for developing countries?
4. **Reliability** — uninterrupted supply? Could it be switched off by producers?
99
What is decoupling?
When countries switch to domestically produced energy rather than importing from foreign suppliers / TNC’s
> moving away from fossil fuels to drive economic growth
100
Define energy mix
The combination of energy sources we use as a country and in what proportions in order to meet energy consumption
101
What does it mean to be energy secure?
A country has enough supply
102
What does it mean to be energy insecure?
A country doesn’t have enough supply
103
What factors will determine the energy mix of a country?
- availability of primary energy resources within the country including tech etc
- energy needs of a country
- financial cost of each energy type
- international relations
104
In what 2 ways can energy consumption be measured?
1. Per capita
2. Energy intensity
105
Roughly, how has the global energy mixes changed?
- **1820** mainly used biofuels
- **1920** intro of oil and some hydropower
- **1960** mainly oil now gas being used
- **1980** increase in hydropower, lots of gas, intro of nuclear
- **2010** use of biofuels, coal, oil, gas etc, intro of renewables
106
What are primary sources of energy?
Those found in nature (not converted or transformed), can be renewable or non-renewable. I.e coal, oil, solar, wind etc
107
What are secondary sources of energy?
Derived from transformation of conversion of primary sources, usually those more convenient i.e electricity
108
What is renewable energy?
Energy from renewable resources that are naturally replenished on a human timescale i.e solar, wind, hydro power
109
What is non-renewable energy?
Energy that comes from natural resources which cannot be readily replaced at a pace quick enough to keep up with consumption i.e coal, oil, gas
110
What is OPEC?
The **Organisation of Petroleum Exporting Companies**, governments and consumers who secure energy pathways and supplies
111
What factors affect per capita energy consumption?
- physical availability
- cost
- standard of living
- environmental priorities (of governments)
- climate
- public perception
- economic development
- technology
112
How does USA and France differ in terms of energy consumption? (Think population, energy mix, sustainability)
**USA**
- rank 2nd in the league table for energy consumers respectively
- 318.9 million population in the USA
- 3/4 of energy comes from fossil fuels
- more self sufficient
**France**
- rank 10th in the league table for energy consumers respectively
- energy consumption is 1/10 of USA’s
- 64.6 million population in the USA
- 1/2 of energy comes from fossil fuels and 40% from nuclear
- over half of supply is imported
113
Name a few oil / gas TNC’s
- ExxonMobil
- Gazprom
- Petrochina
- BP
- Royal Dutch Shell
114
What process enables carbon from the atmosphere to become absorbed by the ocean, and what does this signify about the ocean?
Diffusion — 31% of atmospheric CO2 gets absorbed by oceans
> signifies the ocean is a vital carbon sink and very important in regulating the composition of the atmosphere
115
Where is most of the world’s deforestation and why?
Occurs mostly in developing countries, because:
- rapid population growth
- drive for economic development
- increasing living standards leads to increased food consumption — the need for land for agriculture and cattle ranches
- reliance on wood and biomass
- lack of environmental laws and enforcement
- quarrying
- logging
- palm oil
- HEP
116
What would happen if the rainforest dies off or is lost due to deforestation?
The world would lose a massive carbon sink
117
What things would occur in the area if we lose our rainforests?
- fewer trees means less water is pumped into atmosphere
> rainfall decrease
> temp rise
> drought and wildfires increase
> more trees die / decompose realising CO2
118
What happens to the levels of CO2 in the atmosphere during the winter months?
Levels increase — trees and plants begin to lose their leaves and decay
> less absorption
119
What % of carbon sequestration occurs by mangroves in global oceans?
14%
120
How / where does carbon get stored in mangrove forests?
Carbon is stored in the soils, as the soil surrounding the roots are saturated with saltwater and have little oxygen, which decomposers need to break down plants
121
Name the 5 players in energy pathways
1. **Energy TNC’s**
2. **OPEC**
3. **National Govs**
4. **Consumers**
5. **NGO’s**
122
What is the role of energy TNC’s as players in energy pathways?
- explore, exploit and distribute energy resources
- they own supply lines and invest in distribution and the processing of raw materials
- they respond to market conditions to secure profits
I.e BP, Shell
123
What is the role of NGO’s as players in energy pathways?
Local, National and international environmental pressure groups often campaign against global energy issues i.e nuclear power, global warming and exploitation of energy reserves
I.e Greenpeace
124
What is the role of OPEC as players in energy pathways?
- a permanent IGO made up of 14 key members which produce and export oil
- control 81% of proven oil reserves
- purpose is to coordinate petroleum policies of members
I.e Algeria, Saudi, Venezuela etc
125
What is the role of National Gov as players in energy pathways?
- meet international obligations whilst securing energy suppliers for the nations present and future needs
- support the country’s economic growth
- regulating the role of private companies
- setting policies and enforcing regulations
126
What is the role of consumers as players in energy pathways?
- create demand
- purchasing choices are often based on cost
- decisions about household energy
- oppose local energy production
127
Where are most coal reserves globally?
Central Asia, North American, Australia
128
Where are most gas reserves globally?
Central and northern Asia, north america
129
Where are most oil reserves globally?
South America, Australia, North America
130
What % of worlds energy is still derived from fossil fuels?
86%
131
By what % has global consumption of energy increased since 1990’s?
50%
132
By 2035 what will China be?
The worlds largest energy importer
133
Where is consumption greatest globally?
Where there is lots of industrial activity — I.e USA, China, Europe
> therefore, fossil fuel locations and areas with the highest consumption don’t always match
134
Define energy pathway
The flow of energy between a producer and a consumer. It also refers to HOW energy reaches its consumer; pipelines, transmission lines, shipping routes, roads and rail
135
Define multilateral
Involving more than 2 groups or countries
136
Define bilateral
Involving 2 countries
137
Define transit state
A state through which a movement of energy is planned / made
138
What is a choke point?
A location with tactical and strategic importance I.e narrow land or sea passage, a bridge or tunnel etc.
> the obstruction of which would hamper flows of trade and people
139
Define proxy war
A war instigated by a major power which doesn’t itself become involved
140
List some examples of global chokepoints
- Suez Canal
- Panama Canal
- Strait of Hormuz
- Danish Straits
141
Why are pipelines not always secure for the transfer of energy?
Political decisions may reduce or stop supplies i.e
- internal problems
- wars between countries
- OPEC reducing global prediction
- sanctions against a country I.e Russia to Ukraine
- piracy I.e pirates attacked 42 tankers in Indian Ocean
- leaking pipelines I.e North Sea gas
- a sudden increase in demand causing supplies to divert i.e to China
142
What % of world oil goes through strait of hormuz?
20% passes through Strait of Hormuz
143
What are the 4 ‘unconventional fossil fuels’?
1. **Tar Sands**
A mixture of clay, sand, water and bitumen
I.e Canadian tar sands
2. **Oil Shale**
Oil bearing rocks that are permeable enough to allow oil to be pumped out
3. **Shale Gas**
Natural gas which is trapped in fine-grained sedimentary rocks
4. **Deepwater Oil**
Oil and gas that is found offshore and at considerable ocean depths
I.e Brazilian deep water oil,
Deep water horizon
144
How are tar sands extracted?
- mined then injected with steam to separate it from the sand (diluted steam with hydrocarbons)
145
How are oil shales extracted?
- must be heated at very high temperatures to release the oil from deep within the ground
146
How is shale gas extracted?
- rocks must be fractured (normal drilling won’t work) — water is injected into the rock with chemicals
> forcing rock to split apart and gas is released into the surface
147
How is deep water oil extracted?
- oil rigs move into deep water to find new reserves — drill pipes lowered into sea floor and geology is drilled to find oil reservoirs
> oil gets pumped to surface
148
What are the pros and cons of tar sands
**Pros**
- economically viable when oil prices are higher
- creates jobs
**Cons**
- contaminates rivers
149
What are the pros and cons of oil shale?
**Pros**
- source of energy
- countries who can access it are energy secure
- provides jobs
**Cons**
- expensive
- releases greenhouse gases
- waste is not sustainable
150
What are the pros and cons of shale gas?
**Pros**
- increased energy reserves — less imports needed
- carbon footprint is 50% less than coal
**Cons**
- possible contamination of drinking water
- risk of earthquakes
- still a fossil fuel
- ground subsidence
151
What are the pros and cons of Deepwater Oil
**Pros**
- new reserves to meet demand
- several large reserves — Arctic
- reduces pressure on conventional oil extraction
- boosts economy — more countries can access
**Cons**
- expensive
- dangerous
- difficult to transport
- oil spills
152
What is the impact of tar sands on the carbon cycle?
1.34 million of cars outputs the same as 1 day of greenhouse emissions
> contribution of 3x to global warming greater than normal oil
153
What is the impact of oil shale on the carbon cycle?
Greenhouse gases released which heats up the climate excessively
154
What is the impact of shale gas on the carbon cycle?
Methane gases may escape which adds to greenhouse effect
155
What is the impact of deep water oil on the carbon cycle?
Releasing stored CO2 into the atmosphere (faster than natural processes)
156
What are the environmental impacts of the 4 unconventional fossil fuels?
- loss of habitats
- loss of biodiversity
- harms wildlife
- contaminated waters
- land clearance
- noise pollution
- land scarring
- might upset local tribes
157
List the top 5 renewable resources
1. Hydropower
2. Wind
3. Solar
4. Geothermal
5. Tidal
158
What factors may prevent countries from accessing renewable energy sources?
- not all countries have coasts, strongly flowing rivers or climates with long sunshine hours or persistently strong winds
- there are high financial costs of using non-renewables (especially setup costs), compared to cheaper oil and gas
- using non renewables still has environmental costs — river valleys have to get drowned to create HEP dams, land gets covered with solar farms etc
- whilst the majority of people believe that we should use renewables, most go off the idea when constructing a wind / solar farm nearby to them (NIMBY)
159
What are the downsides of nuclear energy?
- risks to do with safely and security
- the disposal of radioactive waste with an incredibly long decay life
- the tech involved is complex and therefore it’s only available for developed countries
- although operational costs are low, the costs of constructing and decommissioning power stations are high
160
How has / is the composition of renewable energy changed in the UK?
- wind energy provides 30% of the UK’s energy by 2030
- solar power use grew by 86% between 2014-2015
- reduce energy use — LED’s
161
What are some advantages and disadvantages of nuclear power?
**Advantages:**
- reduces energy used from fossil fuels
- requires a small amount of fuel to generate a lot of energy
- continuous and reliable electricity
- nuclear fusion offers the possibility in the future of lots more fuel
**Disadvantages:**
- nuclear accidents
- difficulty and cost of disposing of radioactive waste
- nuclear reactors have a limited life span
- construction of power plants is expensive
162
What are some advantages and disadvantages of wind power?
**Advantages:**
- renewable and so will never run out
- huge potential to expand usage
- price of turbines reduced by 80%
**Disadvantages:**
- dependent on weather
- noise pollution
- visual pollution
- wildlife like birds are threatened
- the transportation and installation of turbines produce greenhouse gases
163
What are some advantages and disadvantages of solar power?
**Advantages:**
- renewable
- no air, water or noise pollution
- less safety risks
- extremely low operating costs when installed
- can be used by individual households
**Disadvantages:**
- can’t collect energy at night
- not possible to store energy
- electricity produced is initially more expensive than conventional power
- weather dependant
164
What are biofuels?
The name for fuels produced from organic matter (biomass) including plant material and animal waste
165
What is bio methane?
Can also be produced from sewage, domestic and animal waste
166
What are the drawbacks of biofuels?
- not accessible to everyone
- takes up space to grow crops for fuel
I.e clears TRF in Brazil to make room
- water intensive
- fertilisers / chemicals enter waters — eutrophication
- requires new infrastructure
167
Define carbon-neutral
Where carbon emissions caused have been balanced out by carbon being absorbed
168
Complete a SWOT analysis for biomass
**Strengths**
- renewable energy source
- lower emissions than fossil fuels
- biodegradable
**Weaknesses**
- takes land from food production
- requires lots of water
- needs pesticides and fertilisers
**Opportunities**
- fuel earns export income
- infrastructure improvements
- positive multiplier effect in rural areas
**Threats**
- takes investment away from food production
- contaminates water resources with pesticides or the overuse of fertiliser
- food shortages
169
Define radical technologies
These are technologies that could reduce carbon emissions but great uncertainty exists over their effectiveness and ability to work.
I.e carbon capture storage, hydrogen fuel cells, electric vehicles
170
What is carbon capture storage (CCS) / how does it work?
Tech used to capture CO2 from coal fired power stations — up to 90% and store it underground
> may cut global emissions by 19%
1. CO2 captured, compressed and transported into an injection
2. Injection gets pumped in liquid form into a typically permeable rock layer
(Needs to be 800m deep)
171
Is CCS financially viable?
No — complex technology involved, along with uncertainty whether it will stay stored or may leak into the atmosphere
172
What are hydrogen fuel cells / how do they work?
Hydrogen currently gets extracted from other fuels i.e oil, gas — could get used in fuel cells to convert chemical energy into hydrogen and electricity.
They combine hydrogen and oxygen to produce electricity, heat and water
> they will produce electricity as long as there is a supply of hydrogen
173
What are some challenges associated with hydrogen fuel cells?
- difficult to find a cheap and easy source of hydrogen
- expensive
174
What are electric cars
Vehicles that operate using 1+ electric motors, only using energy stored in batteries.
175
What are the drawback of electric vehicles?
- £20,000+ — not affordable for everyone
- expensive to charge
- most can only run for 100 miles
- more expensive during times when electricity is expensive
- may have minimal impact overall on carbon emissions
176
How is human activity threatening the water and carbon cycle?
Population increase is causing an increased demand for food, space and fuel among other resources
177
Explain how deforestation impacts the carbon cycle
*A reduction in trees causes an increase of CO2 to be stored in the atmosphere*
> Leads to a reduction of carbon stored as biomass on land
> less photosynthesis
178
What are the 2 types of grasslands? + an example of where they are found
1. **Temperate Grasslands**
Found in continental interiors in mid latitudes
I.e North American Prairies
2. **Tropical Grasslands**
Or savannah in lower latitudes
I.e Africas Serengeti
179
Why are temperate and tropical grasslands being exploited, and how does this impact the carbon cycle?
For agriculture purposes
— ploughing leads to an immediate loss of CO2 and moisture, as well as a change in runoff characteristics
180
Define afforestation
Planting of trees in deforested areas or areas with no prior tree covee
181
Why are nations doing afforestation / reforestation?
To try and offset the loss of benefits that TRF brings
> afforestation is occurring on what was agricultural land however, so is it beneficial?
182
Why is deforestation bad for the carbon cycle?
Plants absorb CO2 from the atmosphere when they grow — this is converted into carbon and stored in the plants branches, leaves etc
> when forests are burnt or cleared, stored carbon is released into the atmosphere, mainly as CO2
183
What does deforestation, afforestation and conversion of grasslands do to the carbon cycle?
They affect terrestrial carbon stores — having implications for the water cycle and soil health
184
What is ocean acidification?
The process of ocean pH decreasing (becoming acidic) as a result of rising CO2 levels within the atmosphere (released by burning fossil fuels)
185
Why does ocean acidification occur?
Because oceans are a carbon sink, meaning it absorbs the high concentrations of CO2 from the atmosphere via diffusion
186
How has the average ocean pH changed since the 19th century to 2015?
19th century: average pH was 8.2 but this had fallen to 8.1 by 2015
187
At what pH do corals stop growing?
When the pH becomes less than 7.8
188
What is the impact of ocean acidification on coral reefs?
As the ocean becomes more acidic, corals cannot absorb the alkaline calcium carbonate that they need to maintain their skeletons — reefs begin to dissolve
I.e the bleaching of the Great Barrier Reef
189
What is the impact of high atmospheric CO2 levels on the ice sheets in the Arctic Circle and Antarctica?
High CO2 levels lead to higher temperatures — this causes an increased rate of melting (particularly the North Pole as it’s thinner ice).
As a result of this, there is less snow / ice land mass, meaning the global albedo affect will decrease — causing further heating, hence more meltwater
190
What is the impact of climate change on shifting climate belts globally?
- expansion of arid areas in North Africa
- reduction in extent of polar regions
- tropical areas may experience more droughts
191
What is a climate tipping point?
A critical threshold that, when crossed, leads to large and often irreversible changes in the climate system — likely to impact human society
192
Why are forests important?
- they sequester CO2 from the atmosphere
- they store carbon
- they transfer moisture from the soil back into the atmosphere via evapotranspiration
193
Define moratorium
Legally authorised period of delay in performance of a legal obligation — deforestation
194
What does the Kuznets curve suggest?
That as a country develops,
1. **Pre Industrial**
Damage to the natural environment will at first increase, as resources are exploited and technologies cause pollution
2. **Industrial** (turning point)
Over time, as tech becomes more efficient, fewer resources are used — pollution levels fall
3. **Post-industrial**
In many developed countries, afforestation is now taking place
195
What is the impact of rising temps (due to GHG emissions) on evaporation rates and the amount of water vapour in the system?
There is increased evaporation and water vapour, this impacts:
- precipitation patterns
- river regimes
- drainage basin stores
- the cryosphere
196
Define the cryosphere
Portions of the earths surface where water is in solid form I.e ice caps, lake ice, snow cover, frozen ground etc
197
How will global precipitation patterns change?
- existing patterns will strengthen — wet weather will get wetter, dry weather will get dryer
- more water to fall in areas with hot air (warm air traps more water vapour)
- as colder areas get warmer and evaporation increases, they too will become wetter
- atmospheric circulation will change
> storm tracks will move further from the equator
198
How has the cryosphere been impacted by global warming?
- shrinking of Antarctic and Greenland ice sheets
- glaciers on planet continue to shrink
- Arctic sea ice and snow cover in the northern hemisphere has continued to decrease in thickness and area
199
What is happening in the Arctic over the past few decades? (serves as a warning to the rest of the planet)
- temps have risen twice as fast as the global average
- there has been a considerable loss of sea ice
- melting of permafrost
- decreased albedo effect — loss of ice
- carbon uptake by terrestrial plants is increasing because of a lengthening growing season
200
What are the positives and negatives on human well-being of a warming climate?
**positives**
- opening of tourism industries in the once ice-bound areas
- access to resources I.e artic oil is more feasible
**negatives**
- environmental degradation
- over exploitation of resources
201
What is a river regime?
An annual variation in discharge of a river, the amount of water that travels through a river and how this changes throughout the year
202
Why is ocean health so important, particularly for developing countries?
- coastal communities depend on fishing for income and food
> FAO estimates fishing supports 500 million people — 90% live in developing countries
- seafood is a dietary preference for some wealthier countries I.e Japan
- aquaculture is on the rise, but it’s productivity is being affected by decking pH and rising temps
- tourism industry is under threat
203
List some ways that’s climate change is impacting the ocean
- coral bleaching
- ocean temps
- food chains / webs
- ocean currents
- ocean chemistry — acidification
- extreme events — cyclones
204
What is Oceania’s risk equation for vulnerability?
Lack of adaptive capacity + exposure = vulnerability
205
Why are coral reefs so important?
- they are some of the most biodiverse ecosystems on earth
- they support 4000 fish species and 800 coral species — may be millions of undiscovered species
- many drugs can be developed from corals
- support commercial and subsistence fisheries as well as jobs
- tourism
- they buffer shorelines against 97% of energy from waves etc
206
What are the 2 strategies that we will have to use to cope with climate change?
1. **Adaptation**
Living with the problem not solving it
2. **Mitigation**
Tackling the root cause of the problem
207
What questions get raised concerning the future?
- will green house gas levels continue to rise?
- what volumes of carbon are likely to be released from peat lands and thawing permafrost?
- will population growth ever level off?
- will economic growth always be carbon-based?
- will fossil fuels be completely replaced?
208
What are the benefits and costs of water conservation + management?
**Benefits**
- fewer resources used, less groundwater abstraction
- attitudinal change operates on a long term basis: use more grey water
**Costs**
- efficiency and conservation cannot match increased demands for water
- changing cultural habits of high water usage needs enforcement by Govs
209
What are the benefits and costs of resilient agricultural systems?
**Benefits**
- higher tech, drought-tolerant species help resistance to climate change and increase in diseases
- more indoor intensive farming
- better practices generate healthier soils and may help CO2 sequestration and water storage
**Costs**
- more expensive tech
- high energy costs from indoor / intensive farming
- genetic modification is still debated
- growing food insecurity adds pressure to find ‘quick fixes’
210
What are the benefits and costs of land-use planning?
**Benefits**
- soft management — land use zoning, buildings restrictions in vulnerable plains
- enforcing strict runoff controls and so always
**Costs**
- needs strong governance, enforcement and compensation
- a political ‘hot potato’
211
What are the benefits and costs of flood-risk management?
**Benefits**
- hard management traditionally used
- simple changes can reduce flood risk i.e permeable tarmac
- reduced deforestation and more afforestation upstream to absorb water and reduce downstream flood risk
**Costs**
- debate over funding sources
- constant maintenance required
- land owners may demand compensation for afforestation
212
What are the benefits and costs of solar radiation management?
**Benefits**
- the orbiting satellites to reflect inward radiation back into space
- it could cool the Earth within months and be relatively cheap compared with mitigation
**Costs**
- untried and untested
- would reduce but not eliminate the worst effects of greenhouse gases
- involves tinkering with a very complex system
213
What is the long term solution to global warming?
Rebalancing the carbon cycle — reducing the concentration of greenhouse gases in the atmosphere
214
What UK organisation is responsible for mitigation policies for climate change?
Department of Energy and Climate Change (DECC)
215
List possible mitigation policies used by the DECC
1. **Carbon taxation:**
Carbon price floor tax sets a minimum price companies have to pay to emit CO2
2. **Renewable Switching:**
the relationship between the big energy producers and gov dictates the amount of switching from fossil fuels to renewables and nuclear power
3. **Energy efficiency:**
The green deal scheme encouraged energy saving improvements to homes, such as efficient boilers and lighting, and improved insulation
4. **Afforestation:**
Tree planting in the UK is increasing — this helps with carbon sequestration
5. **Carbon sequestration:**
Few actual geologic CCS projects exist globally, despite its potential
216
What are some of the supposed outcomes by 2100 according to the Inter-governmental Panel on Climate Change?
1. Things will be the same
2. There will be some mitigation
3. There will be strong mitigation
4. There will be aggressive mitigation
217
What are some of the benefits of natural grasslands?
grasslands:
- trap moisture and floodwater
- absorb toxins from soils
- provide cover for dry soils
- maintain natural habitats
- acts as a carbon sink
218
List the geological processes in the carbon cycle
- volcanic outgassing
- chemical weathering
- carbonate pump
