Carbon Cycle Flashcards
Carbon cycle ( locale scale)- transfers (7)
Photosynthesis- living organism convert Carbon Dioxide from the atmosphere and water form the soil, into Oxygen and glucose using light energy- by removing CO2 from the atmosphere, plants are sequestering carbon and reducing the potential impacts of climate change
Respiration- living organisms convert oxygen and glucose into energy
Combustion- when fossil fuels and organic matter such as trees are burnt, and emit CO2 in the atmosphere. Wild fires can also emit CO2
Decompositions- when living organisms die, they are broken down by decomposers, which respire, returning CO2 into the atmosphere. Some Carbon is also returned to soil
Burial and compaction- sea shell fragments become compacted over time to form limestone. organic matter from vegetation and decaying marine organisms may compact over time to form fossil fuel deposits
Carbon sequestration- transfer of Carbon from the atmosphere to other stores and can be both natural and artificial
Weathering and Erosion- rocks are eroded in land or broken down by carbonation weathering. When CO2 in the Air mixes with rainwater which creates a weak carbonic acid which aids erosion of rocks!
Psammarsere vegetation succession (4)-(5)-(4)
Pioneer stage:
. Calcareous sands ( means high levels of carbonation weathering) from lithosphere to atmosphere and hydrosphere
. Remains of marine organisms ( mainly from shells are rich in calcium
. It can get very exposed so it may get weathered ( carbonation )
. High percentage (90%) of bare sand ( very low rates of photosynthesis)- the pioneer stage is a source
. Very little hummus content
Building stage:( grey dunes)
.The vegetation succession is being more diverse so increase in photosynthesis
. Marram grass- ( the fundamental thing in creating sand dunes )
. They offer protection from winds and so they are favourable for other plants eg shrubs
. Organic matter increase when it dies as it decomposes ( which then became soil)
. Transfers carbon from atmospheric store to biospheric/ lithospheric store
Seral stage:
Climatic climax:
. Vegetation succession reach maturing and a state of balance ( dynamic equilibrium)
. Climate is the biggest factor in determining the state of the ecosystem
. High rates of photosynthesis resulting in becoming high carbon sinks
. Little to no bare sand
Changes over time
Natural processes
. Wild fires-Transfers Carbon from biosphere to atmosphere as CO2 is released through burning, which encourages the growth of plants in the long term ( there is a debate whether preventing wild fires are beneficial)
.Volcanic Activity- Carbon stored within the earth is released during volcanic eruption, mainly as CO2 gas- Mt Pinatubo produced so2 which blocked radiation from the sun, lowering global temperatures
Human impacts
. Fossil fuel use- combustion emits CO2 to the atmosphere from a long term carbon sink
. Farming practices- Pastoral framing releases CO2 as animals respire. Ploughing can release CO2 stored in the soil.
Deforestation- clearing the land for housing and farming can rapidly releases carbon stored in plants using slash and burn techniques
Positive feedback loops ( triggered by human intervention)
. Combustion of fossil fuels ( anthropogenic activity) can trigger the carbon emissions
. More carbon in the atmosphere which increases temperature ( enhancing green house effect)
. This melts permafrost creating the Active layer, that means soil and micro organisms become active ( decomposition occurs). This released carbon dioxide and methane which further enhanced CO2 in the atmosphere
Positive feedback loops- sea ice ( Arctic)
. Combustion of fossil fuels Can increase carbon emissions which increases temperatures ( leads to global warming)- enhanced green house effect
. Leads to reduction of surface area of sea ice which leads to an increase on insolation because ocean has a lower albedo than ice so more radiation is absorbed in earths surface
. More terrestrial radiation which can increase the warming of the earth
Negative feedback
.Increased photosynthesis by plants and rising global temperature allows vegetation to grow in new areas, where permafrost has melted
. Higher temperatures and more CO2 cause a greater carbon fertilisation in plants so they absorb more CO2
. Plankton and dead organisms photosynthesis, warmer oceans and more sunlight due to climate change, boost a chemical, forming clouds
. Increase cloud cover decreases warming and more photosynthesis reduce CO2
Geo politics ( Amazon rainforest) (3)
. Lula had a program to save the Amazon ( net zero deforestation plan)
. He created a legal framework from 2004- 2012 where deforestation was reduced by 83% from 28000 sq/Km to 4600 sq/km
. bolsenaro elected where he encourages deforestation- created in 2018 7,500 sq/km
Carbon and water cycle links (4)
. Rain may fall over deforested land due to wind, causing erosion, increasing carbon content in rivers. The water leaves the rainforest cycle through streamflow
. there is less evapotranspiration in deforested areas, causing drought periods.
. Deforestation in peat lands and the digging of drainage channels reduce water storage, which decomposes peat land quickly as it is not preserved ( no longer in anaerobic conditions)- from lithosphere to atmosphere
. Blocking drainage ditches helps restore natural environment, by increasing soil water storage and decreasing surface runoff
( increase water table and decrease flood risk)
Carbon stores
. Marine sediments
. Oceans
. Fossil fuel deposits
. Soil and organic matter
. Atmosphere
The enhanced green house effect
The process that is currently causing global warming when high levels of green house gases are produced by humans
. Radioactive forcing refers to the difference between incoming solar radiation absorbed by the earth and the energy radiated back into space- CO2 is the single most important anthropogenic greenhouse gas in the atmosphere, contributing to around 65% to radioactive forcing
. Increase global temperatures makes summer storms more likely to decrease rainfall in summer but increase average winter Randall
Causes
Fertilisation- significant cause of green house gases as well as rice padi fields where increase of agricultural productivity, has increased methane emissions in the atmosphere- more sustainable grains eg quino are being considered as substitutes which require less water to grow
milankovitch cycle
. ice core data from Antartica suggest past temperature changes occured before carbon dioxide levels have risen
.Variations of different earths orbit can create a heating effect from the sun which can increase global temperatures. This causes glaciers to melt and therefore increasing flows in the carbon cycle- global temperatures to rise further ( positive feedback)
mitigating
