The Carbon Cycle Flashcards
What are 5 of the most common carbon compounds? (It bonds easily with other molecules)
- Carbon dioxide - a gas found i the atmosphere soils and oceans
- Methane - a gas found in the atmosphere, soils and oceans and sedimentary rocks
- Calcium carbonate - a solid compound found in calcareous rocks, oceans and in the skeletons and shells of ocean creatures
- Hydrocarbons - soils, liquids or gases usually found in sedimentary rocks
- Bio-molecules - complex carbon compounds produced in living things. Eg DNA, proteins, fats. Form 50% of the total sry mass of living things
What is Anthropogenic CO2?
Carbon dioxide generated by human activity
What is carbon sequestion?
The capture of carbon dioxide (CO2) from the atmosphere or capturing anthropogenic (human) CO2 from large scale stationary sources like power plants before it is released into the atmosphere. Once captured, the CO2 gas (or the carbon portion of the CO2) is put into long term storage.
What is carbon sink?
A store of carbon that absorbs more carbon than it releases
What is weathering?
The breakdown of rocks in situ by a combination of weather, plants and animals.
What is the carbon cycle ?
1.Carbon is an essential building block for all life on earth.
2.It plays a major role on regulating global climate, particularly temperature and the acidity of rain, rivers and oceans.
3. The carbon cycles have inputs, stores, flows and outputs that transfer carbon from one place to another and either deplete or build carbon stores
Describe and explain the varying size of global carbon flows?
- Slow carbon cycle: the movement of carbon between the atmospheric, oceans and lithospheres
- the atmosphere, oceans and land are linked together transferring carbon in a giant slow - moving system which takes between 100 and 200 million years for carbon to flow through it - Fast carbon cycle: the movement of carbon from living things to the atmosphere or oceans
- the fast cycle through the biosphere moves up to a 1000x more carbon in a shorter space of time
What are the processes changing the size of these stores?
Photosynthesis
Respiration
Combustion
Decomposition
Diffusion
Weathering ands erosion
Burial and compaction
Carbon sequestion
Explain how photosynthesis changes the size of the carbon stores?
Living organisms convert carbon dioxide from the atmosphere and water from the soil, into oxygen and glucose using light energy. By removing co2 from the atmosphere, plants are sequestering okays carbon and reducing potential impacts of climate change. The process of photosynthesis occurs when chlorophyll in the leaves of the plant react with co2 to create the carbohydrate glucose. Photosynthesis helps to maintain the balance between oxygen and co2 in the atmosphere.
Carbon dioxide + water -> light energy -> oxygen + glucose
Explain how respiration changes the size of the carbon stores?
Respiration occurs when plants and animals convert oxygen and glucose into energy which then produces waste products of water and co2. It is therefore chemically the opposite of photosynthesis.
Oxygen + glucose -> carbon dioxide + water
During the day, plants photosynthesise, absorbing significantly more co2 than they emit from respiration. During the night they do not photosynthesise but they do respire, releasing more co2 than they absorb. Overall, plants absorb more co2 than they emit, so are net carbon dioxide absorbers (from the atmosphere) and net oxygen producers (to the atmosphere).
Explain how combustion changes the size of the carbon stores?
When fossil fuels and organic matter such as trees are burnt, they emit CO2 into the atmosphere, that was previously locked inside of them. This may occur when fossil fuels are burnt to produce energy, or if wildfires occur
Explain how diffusion changes the size of the carbon stores?
The oceans can absorb co2 fro the atmosphere, which has increased ocean acidity by 30% since pre-industrialised times. The ocean is the biggest carbon store, but with carbon levels increasing seawater becomes ore acidic which is harming aquatic life by causing coral bleaching. Many of the world’s coral reefs now are under threat
Explain how weathering and erosion changes the size of the carbon store?
Rocks are eroded on land or broken down by carbonation weathering. Carbonation weathering occurs when co2 in the air mixes with rainwater to create carbonic acid which aids erosion of rocks such as limestone. The carbon is moved through the water cycle and enters the oceans. Marine organisms use the carbon in the water to build their shells. Increasing carbon dioxide levels in the atmosphere, may increase weathering and erosion as a result, potentially affecting other parts of the carbon cycle.
Explain how burial and compaction changes the size of the carbon store?
When shelled marine organisms due, their shell fragments fall to the ocean floor and become compacted over time to form limestone. Organic matter from vegetation and decaying marine organisms is compacted over time, whether on land or in the sea, to form fossil fuel deposits.
Explain how carbon sequestration changes the size of the carbon store?
Transfer of carbon from the atmosphere to other stores and can be both natural and artificial. A plant sequesters carbon when it photosynthesises snd stores the carbon in its mass. Factories are also starting to use carbon sequestration in the for of Carbon Capture and Storage. CO2 is captured and transported via pipelines to depleted gas fields and saline aquifers.
What are the advantages of carbon sequestration?
- can be fitted to existed coal power station
- capture 90% of co2 produced
- there is a demand for co2 (beer, cola), so transport systems via pipeline in liquid form already exist
- potential to capture half the worlds co2 emissions
What are the disadvantages of carbon sequestration (CCS)?
- high cost is the main restriction to the growth of CCS
- increased energy demand for power stations
- may not be space to fit to existing power stations
- economically viable in some cases as it is used to push oil out the ground, thus increasing fossil fuel usage
Describe and explain the varying size of global carbon stores?
The lithosphere (biggest store, however unevenly distributed, north south hemisphere) has the largest magnitude, with a total percentage of carbon around 99.9%. The carbon comes in the forms sedimentary rocks, organic carbon, fossil fuels, marine sediments.
- 400 billion metric tons of carbon remain as fossil fuels
- 1500 billion metric tons of carbon stored in organic matter
The hydrosphere has the second largest magnitude, around 0.007% of the total carbon %. It comes in the form of carbonate ions, bicarbonate ions and dissolved co2.
- 38,000 billion metric tons of carbon
The cryosphere has a smaller magnitude of 0.0018% of total carbon. It is in the form of frozen mosses
Smaller is the atmosphere, with 0.0015%. Carbon stored in the form of gaseous carbon.
- makes us 0.04% of the atmosphere
The smallest is the biosphere, with a magnitude f 0.0012 %. Stored in the form of living plants and animals.
- 19% of this store is in plants
How does Wildfires effect the carbon cycle over time?
Natural Variation
- combustion of biomass and fossil fuels
Combustion occurs when any organic material is related in the presence of oxygen to give off the produces of c02, h20 and energy. This organic material can be vegetation or fossil fuel such as natural gas, oil or coal. Trees die after sever fires, setting the stage for new growth, therefore no net carbon change. The fires only consume 10-20% of the carbs and it is emitted immediately into the atmosphere. It kills trees but does bot consume them. So new trees grow (storing carbon), old trees decompose (emitting carbon) and the organic layer of the soil accumulates (storing carbon). This balance between simultaneous production and decomposition determines whether the forest is a net source or sink. Left alone, terrestrial and atmospheric conditions stay more or less in balance.
How does volcanic activity effect the carbon cycle over time?
Natural Variation
The warming effect of emitted co2 is counterbalanced by the large amounts of sulphur dioxide that is give out-conversions of thus it sulphuric acid, which forms fine droplets, increases the reflection of radiation from the sun back into space, following the earths lower atmosphere. The amounts of co2 released have not been enough to produce detectable global warming.
- in 1815 MT Tambrora eruption in Indonesia produces sulphur dioxide gas, which blocked radiation from the sun and lowered global temperatures by 0.4 to 0.7 degrees in 1816.
However in this way volcanoes can influence the carbon cycle by reducing photosynthesis rates, which in turns affects the water cycle.
How does hydrocarbon fuel extraction and burning affect the carbon cycle over time?
HUMAN
Cement manufacture contributes co2 to the atmosphere when calcium carbonate is heated producing lime and co2. Co2 is also produced by the burning of fossil fuels that provide heat for the cement manufacture process
How do farming practises affect the carbon cycle over time?
HUMAN
Arable farming releases co2 as animals respire. Ploughing can release co2 stored in the soil into the atmosphere. In addition to the effects on the soil from ploughing, emissions from the tractors increase carbon dioxide levels in the atmosphere.
How does deforestation affect the carbon cycle over time?
HUMAN
Most deforestation is driven by the need for extra agricultural land. When forests are cleared for conversion to agriculture or pasture, a large proportion of the above ground biomass may be burned, rapidly releasing most of its carbon into the atmosphere. Some of the wood may be used for wood products and so preserved for a longer period of time. Forests clearing also accelerates the decay of dead wood,litter and below ground organic carbon
- according to global forest watch that since 2001 to 2018, the tree cover lost globally is 1.5x the size of the UK. This has released an estimated 98.7 Gtc of Co2 emissions.
How does land use change (urban growth) affect the carbon cycle over time?
As cities grow, the land use changes from agricultural or natural to built environment. The co2 emissions resulting from energy consumption for transport, industry and domestic use and cement production have been required to built the increase in infrastructure.
- urban areas estimated to be responsible for 75% of global carbon emissions
