The Carbon Cycle Flashcards
What are the 4 Carbon Stores?
-The Atmosphere e.g. carbon dioxide
-The Hydrosphere
-The Lithosphere
-The Biosphere
What are the 3 Processes involved in the Carbon Cycle?
-Respiration
-Photosynthesis
-Volcanic eruptions
What is a Store/Reservoir?
Where the carbon is held.
What are Fluxes?
The flows of movement between the stores, which can operate at local and global scales.
What are Petagrams (Pg) or Gigatonnes (Gt)?
The units used to measure carbon in one petagram (Pg), also known as gigatonne (Gt), is equal to one billion tonnes.
What is Crustal?terrestrial/geological carbon storage?
Sedimentary rocks. very slow cycling over millennia.
Long term store (hundred of years to millennia).
PgC (Petagrams average) - 100,000,000 fossil fuels store an extra 4,000.
What is Oceanic (deep) storage?
Most carbon is dissolved, inorganic carbon stored at great depths, very slow cycled.
Long term store (hundred of years to millennia).
PgC (Petagrams average) - 38,000.
What is Terrestrial soil storage?
From plant materials (biomass) microorganisms break most organic matter down into CO2 in a process which can take days in a hot and humid climate to decades in colder climates.
Short term store (seconds to decades).
PgC (Petagrams average) - 1,500.
What is Oceanic (surface) storage?
Exchanges are rapid with the atmosphere through physical processes such as C02 dissolving in the water and biological processes involving plankton. Some of this carbon sinks into the deeper ocean pool.
Short term store (seconds to decades).
PgC (Petagrams average) - 1,000.
What is Atmospheric storage?
CO2 AND CH4 store carbon as greenhouse gases with a lifetime up to 100 years.
Short term store (seconds to decades).
PgC (Petagrams average) - 560.
What is Terrestrial Ecosystems storage?
CO2 is taken from the atmosphere by photosynthesis, carbon is stored organically, especially in trees. Rapid exchange with the atmosphere - second/minutes.
Short term store (seconds to decades).
PgC (Petagrams average) - 560.
What is Geological Carbon?
-It’s formed when rocks such as sedimentary rocks are created e.g. limestone and chalk.
-A natural cycle that moves between land, oceans and the atmosphere.
-Involves a number of chemical reactions that create new stores which trap carbon for significant periods of time.
-There tends to be a natural balance between the amount of carbon being released and the amount being absorbed.
-There can be occasional disruptions and short periods before this balance is restores, such as during a volcanic eruption.
What is a Case Study Example of Geological Carbon?
One of the earth’s largest stores of carbon is the Himalayas which started off as oceanic sediments rich in calcium - this is now being weathered and returned back to the oceans.
What is Biologically derived Carbon?
-It’s created from dead organisms such as coal and shale.
-These organisms absorb carbon during respiration and photosynthesis.
-Once they die they (if they are in oceans) sink to the sea bed.
-They are then buried under sinking sediments and form layers called strata.
-Eventually, the strata are squeezed together as a result of the weight on top, and can create fossil fuels such as coal and oil.
What is Outgassing?
Releasing carbon dioxide from the mantle during a volcanic eruption.
What is Metamorphism?
Releasing carbon dioxide from rocks which are rich in carbonates, his occurs through the presence of intense heating along subduction plate boundaries metamorphoses (alters) sedimentary rocks by baking, creating metamorphic rock.
What is Chemical Weathering?
Carbon dioxide within the atmosphere combines with rainfall to produce a weak acid (acid rain) that dissolves carbon rich rocks, releasing bicarbonates.
What is the 1st of the 6 Important Stores and Fluxes?
Terrestrial carbon, held within the mantle, is released into the atmosphere as carbon dioxide (CO2) when volcanoes erupt. This is known as outgassing.
What is the 2nd of the 6 Important Stores and Fluxes?
CO2 within the atmosphere combines with rainfall to produce a weak acid (acid rain) that dissolves carbon-rich rocks, releasing bicarbonates. This is chemical weathering.
What is the 3rd of the 6 Important Stores and Fluxes?
Rivers transport weathered carbon and calcium sediments to oceans, where they are deposited.
What is the 4th of the 6 Important Stores and Fluxes?
Carbon in organic matter from plants and from animal shells and skeletons sinks to the ocean bed when they die, building up strata of coal, chalk and limestone.
What is the 5th of the 6 Important Stores and Fluxes?
Carbon-rich rocks are subducted along plate boundaries and eventually emerge again when volcanoes erupt.
What is the 6th of the 6 Important Stores and Fluxes?
The presence of intense heating along subduction plat boundaries metamorphoses (alters) sedimentary rocks by baking, creating metamorphic rocks. CO2 is released by the metamorphism of rocks in rich in carbonates during this process.
How much CO2 did the 2010 Icelandic Eruption Release?
It emitted between 150,000 and 300,000 tonnes of CO2 per day. It contributed less than 0.3% of global emissions that year.
What is a Carbon Source?
It is shrinking in size and releasing emissions e.g. outgassing (volcanoes), combustion, human respiration.
What is a Carbon Sink?
It is growing in size and storing carbon e.g. plants/trees, oceans.
What does the Amount of Carbon in the Atmosphere at any one time Depend on?
The balance that exists between the sinks and sources.
What are Positive (amplifying) Feedback Loops
They occur when a small change in one component causes changes in other components, this shifts the system away from its previous state and towards the new one.
What are Negative Feedback Loops
Earths systems normally operate y negative (stabilising) feedbacks, maintaining a stable state by preventing the system moving beyond certain thresholds i.e. only change is cancelled out, maintaining equilibrium.
What is Respiration?
A chemical process that happens in all cells and is common to both plants and animals. Glucose is converted into that can be used for growth and repair, movement and control of body temperature in mammals. Carbon dioxide is then returned to the atmosphere, mostly by exhaled air.
What is Photosynthesis?
The process whereby plants use the light energy from the sun to produce carbohydrates in the form of glucose.
-Green plants absorb the light energy using chlorophyll (a green substance found in chloroplasts in plant cells) in their leaves.
-The absorbed light energy converts carbon dioxide in the air and water from the soil into glucose. During this process, oxygen is released into the air.
-Some glucose is used in respiration, the rest is converted into starch, which is insoluble but can be converted back into glucose for respiration.
What is 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 as carbon dioxide . Some organic material passes into the soil where it may be stored for hundreds of years.
What is Combustion?
Organic material contains carbon. When it is burned in the presence of oxygen (e.g. coal in a power station) is is converted into energy, carbon dioxide and water. This is combustion. The carbon dioxide is release into the atmosphere, returning carbon that might have been stored in rocks for millions of years.
What is the Carbonate Pump?
-Dumps carbon but the atmosphere into the hydrosphere.
-When organisms (shells) sink and die they dissolve into the sea as smaller sediment.
-Forms limestone sediment at high pressure and low temperature or flows through the ocean as carbon.
-Calcium carbonate in the ocean forms shells by animals absorbing it to make their shells.
What is the Physical Pump?
-Upwelling means water rises upwards.
-Warm water releases more CO2.
-Extra cold salty dense water absorbs more CO2 in Antarctic.
-Downwelling, cold water sinks.
-Current starts in the polar oceans, past Antarctic, then Indian Ocean and Western Pacific.
What is the Biological Pump?
-It’s a sequestrian (storage) of CO2 to oceans by phytoplankton.
-Phytoplankton float on the ocean surface to access sunlight and photosynthesis. -> they are autotrophs (an animal capable of producing its own food) and are the base of the marine food web.
-They make up over 1/2 of the planets biomass.
-Carbon is passed up the food chain by consumers which in turn release CO2 back to the atmosphere.
-0.1% of carbon reaches the sea floor through decomposition and sedimentation.
-Phytoplankton sequesters over 2 billion metric tonnes of CO2 annually to the deep ocean.
-The processes in total transfer 5-15 gigatonnes of carbon from the atmosphere to the deep ocean each year.
How does Terrestrial Sequestration occur?
-Primary producers (plants) take in carbon through photosynthesis and then release CO2 back into the atmosphere through respiration.
-Consumer animals then eat these plants and absorb the carbon which becomes part of its fats and proteins.
-Initially after the animal has died, microorganisms and detritus feeders such as beetles feed on waste material which becomes part of these microorganisms.
-After death, tissues decay into the soils. This process is affected by climate and decomposition will happen fastest in tropical climates (warm and damp) or, in Arctic biomes, the process can be ‘locked down’ for substantial time periods.
What Percentage of Tree’s Biomass is made up from the CO2 that it sequesters and converts into cellulose?
95%
What does Carbon Fixation turn into?
Gaseous carbon into living organic compounds that grow
What Percentage of Global Carbon is Stored in Soils?
20-30%, sequestering about twice the quantity of carbon as the atmosphere and three times that of terrestrial vegetation. Whether the soil sequesters or emits CO2 depends on local conditions.
How does Climate affect Carbon Sequestration in Soils?
This dictates plants growth and microbe activity. Rapid decomposition occurs at higher temperatures or under water logged condition. Places with high rainfall have an increased potential carbon storage than the same soil type in lower rainfall places. Arid soils store only 30 tonnes per hectare compare with 800 tonnes per hectare in cold regions.
How does Soil Type affect Carbon Sequestration in Soils?
Clay-rich soils have a higher carbon content than sandy soils as clay protects carbon from decomposition.
How does Management and use of Soils affect Carbon Sequestration in Soils?
Since 1850, soils globally have lost 40-90 billion gigatons of carbon through cultivation and disturbance. Current rates of carbon loss due to land-use change are 1.6 ± 0.8 billion gigatons of carbon per year.
What Percentage of Short-wave Radiation is Reflected by clouds, aerosols and gases in the atmosphere and by the land surface?
31%
What Percentage of Short-Wave Radiation is Absorbed?
69%, particularly by the oceans.
What happens when Long Wave Radiation is Reflected?
A large amount is re-radiated back to the Earth by clouds and greenhouse gases which traps the long wave radiation in our atmosphere.
What Life Supporting Average Temperature does the Natural Greenhouse Effect give us?
15°c
Without the effect our average temperature would be -6°c.
What is the Present Geological Time we are living in?
The Holocene period but many refer to it now as the Anthropocene because of the profound changes caused by humans.
The natural greenhouse effect has become enhanced; CO2 in the atmosphere has increased in volume by 40% in the last 300 years.
What are the Causes of Greenhouse Gases?
-Industry (combustion of fossil fuels).
-Transport (CO2 emissions).
-Agriculture (Livestock - methane, Deforestation - farm land, loss of soil carbon from ploughing).
-Electricity generation (increased demand due to rising population).
-Cement production (the most consumed product in the world after water, chemical processes involved in the production release a substantial amount of CO2 - 6% of global emissions).
-Wetland/peatland loss (the nature of wetlands is shaped by water and rainfall patterns - the unpredictable change due to climate change may result in wetlands drying out, peatlands store 550Gt of carbon - twice as much as all of the world’s forest biomass combined by only cover 3% of the earth’s surface).
How has Human Activity Effected Carbon?
-Through burning fossil fuels we have transferred considerable amounts of carbon from fossil stores, where exchanges are very slow, into the fast category , significantly disturbing the carbon cycle.
How is Temperature Distributed?
-The amount of solar energy (solar insolation) reaching the Earth’s surface varies at different locations which in turn influences temperature.
-The angle of the sun’s rays makes solar insolation intense at the equator but dispersed over a wider area at the poles.
-Different characteristics of the Earth’s surface (how light or dark it is) also affects how much heat is absorbed or reflected.
How is Precipitation Distributed?
-The heating of the atmosphere and surface controls the temperature, pressure, movement and moisture content of the air.
-Because solar radiation is most intense at the equator, low pressure systems dominate there, meaning rainfall all year round.
-Regional and seasonal variations also occur, because of the effects of relief, pressure patterns and wind systems.
What are the Impacts of using Fossil Fuels?
-The combustion of fossil fuels is explicitly linked greenhouse gas concentrations, rising global temperatures and seal levels.
What are the 3 Main Areas of Fossil Fuel Impact?
-Climate
-Ecosystems
-Hydrological Cycle
What are the Negative Impacts on the Climate of using Fossil Fuels?
-Atlantic and Southern Ocean thermohaline circulation may weaken, altering the transfer of heat by oceans.
-The hottest year on record was 2015, with average world temperature 1°c above that of pre-industrial era; 2011-2015 were the five hottest years on record.
-The Sahel, Mediterranean, South Africa and South Asia will become drier, with drought more common in the tropics and subtropics - but some uncertainties remain due to other factors (El Nino).
-Antarctic ice shelves will melt, adding more freshwater to the Southern Ocean, changing density and convection.
-The average Arctic temperature has already increase at twice the global average over the last 200 years. Snow and ice cover will contract with the ablation of glaciers.
What are the Negative Impacts on Ecosystems of using Fossil Fuels?
-Marine biodiversity may be lost as fish move away from warming sea temperatures and about 80% of coral reefs could be bleached (e.g. Great Barrier Reef).
-Habitat changes will mean 10% of land species with limited adaptability will face extinction as the climate gets warmer and either wetter or drier. Rates of extinction could rise to 15-40% of all species, especially in in high polar regions.
-Plant changes will lag behind animal changes, as they cannot move, and they will face pests and diseases where there is less cold weather to kill them.
What are the Negative Impacts on the Hydrological Cycle of using Fossil Fuels?
-Permafrost areas will thaw and add more water to Arctic rivers.
-Uncertainty remains over increased river flooding, since multiple factors are involved, but more flash flooding is likely as a result of more intense precipitation.
-A shift of subtropical high-pressure areas northwards will cause a 20-30% decrease in water availability in Mediterranean climate zones.
What is Energy Consumption?
The amount of energy that is used.
What are the Factors Affecting Energy Consumption?
-Physical availability
-Technology
-Climate
-Cost
-Economic development
-Environmental priorities
How does Physical Availability Affect Energy Consumption?
-Is energy available within the country or does it have to be imported?
-Imported energy requires transport which adds onto the overall cost for the consumer. Rising costs are likely to decrease consumption.
-Domestic energy can be difficult to access and require expensive technology.
How does Technology Affect Energy Consumption?
-Can help with energy exploitation that is difficult to access.
-This is likely to increase energy consumption, however much of the modern technology available is energy thirsty.
How does Climate Affect Energy Consumption?
-Very high levels of consumption North America, the Middle East and Australia reflect the extra energy require to make the extremes of heat and cold more comfortable.
-Low energy consumptions in much of Africa, a continent of considerable heat, reflects its relatively low levels of economic development.
How does Cost Affect Energy Consumption?
-This includes a number of things: physical exploitation ; processing (converting primary into a secondary resource); delivery to the consumer.
-Relatively low energy costs may be expected to boost consumption.
How does Economic Development Affect Energy Consumption?
-The same energy costs may be perceived as expensive in one country and acceptable in another.
-The public perception will depend very much on the level of economic development and the standard of living.
-The higher these are, the less the sensitivity to energy cost.
-Developed countries have relatively high levels of energy consumption.
-The energy needs of all domestic appliances that make everyday living more comfortable and those forms of transport hat allow us to travel more easily.
How do Environmental Policies Affect Energy Consumption?
-Out of concern for our environment in general and about carbon emissions in particular, a government might not take the cheapest route to meeting its energy needs.
-Renewables such as wind turbines and solar panels are not necessarily environmentally friendly.
-Also the cost of ‘green’ energy policy could have a slightly depressing impact consumption, as would any governments drive to raise energy efficiency and energy saving.
What is GDP?
Gross domestic product
The amount of income generated from products and services per year.
What is an Energy Mix?
The energy mix of a country is the proportion of each primary energy resource it uses per year. These resources may be domestic or imported.
What are Non-Renewables (finite)?
E.g. coal, oil and gas.
-Exploitation and use of these stocks will lead to their exhaustion.
What are Renewables?
E.g. solar, wind and wave power.
-These are continuous flows of nature and can be constantly re-used.
What are Recyclables?
E.g. reprocessed uranium and plutonium from nuclear power plants and heat recovery systems.
-Reprocessed energy.
What are the Factors Effecting the Energy Mix?
-Availability of primary energy resources within the country as well as their access to technology to extract the resources.
-The accessibility of primary energy resources from outside the country.
-The energy needs of the country, based on economic development, lifestyle and climate.
-Changing energy consumption patterns, linked to population and economic growth.
-National and regional policies that affect energy production and consumptions e.g. climate change.
-Cultural and historical legacies and geopolitical links.
-Financial costs of each energy option.
What is the Example for Availability of Primary Energy Resources (factors effecting energy mix)?
Iceland - Domestic geothermal energy.
What is the Example for Accessibility of Primary Energy Resources (factors effecting energy mix)?
Europe - In 2013, Russia exported 8% of its natural gas to Europe.
What is the Example for the Energy Needs of the country (factors effecting energy mix)?
USA - Consumerist lifestyle meaning higher demand. Plus, hot/cold climate meaning air conditioning and heating required.
What is the Example for Changing Energy Consumption Patterns (factors effecting energy mix)?
India - population of 1.4 billion meaning high demand.
What is the Example for National and Regional Policies that Affect Energy production and consumption (factors effecting energy mix)?
UK - national policies to reduce emissions and invest in renewables.
What is the Example for Cultural and Historical legacies and Geopolitical links (factors effecting energy mix)?
India - struck up a deal with Canada for it to provide India with 3.2 kilo of uranium.
What is the Example for Financial Cost of each Energy option (factors effecting energy mix)?
Countries with little capital e.g. India, consumer the cheapest resources, which is currently fossil fuels.
What is Primary Energy?
Natural energy resources that have not been converted into another form of energy e.g. coal, oil, gas. (Consumed in their raw form).
What is Secondary Energy?
Refers to what the primary source has been converted into, usually electricity.
What was the UK’s Energy Mix in 2023?
Coal - 1%
Natural Gas - 32%
Wind - 29.4%
Biomass - 5%
Solar - 4.9%
Nuclear - 14.2%
Imports - 10%
What is Energy Security?
Being able to access reliable and affordable energy sources - either domestic or from ‘friendly’, domestic countries.
Is the UK Energy Secure?
The UK now imports more energy than it produces domestically due to a decline in North Sea oil and gas reserves.
This means that the UK has an energy deficit and is energy insecure.
Which country was Europe Dependent o for Gas?
-Russia, for about 40% of Europe’s gas supply before the conflict
-Moldova and North Macedonia relied solely on Russian gas, Finland and Latvia relied on it for over 90% of their energy.
What are the Factors Affecting Energy Consumption in the UK?
Physical Availability - Was previously heavily dependent on domestic coal, now increase of oil and gas due to the discovery of large reserves in the North Sea after the 1970s.
Cost - North Sea oil is expensive to extract, stocks of it are declining forcing the UK to import.
Technology - There are 150 years’ worth of coal reserves left in the UK but technology and environmental policy make extraction unrealistic and expensive.
Political Considerations - Privatisations of the UK’s energy supply industry means overseas companies decide which energy sources are used to meet UK demand.
Level of Economic Development - GDP per capita = US$41,200
Energy use per capita = 2752 kg oil equivalent
Average annual household energy costs = £1,300
Environmental Policies -
