Unit 4 Notes Flashcards
What is the Carbon Cycle?
A biochemical cycle by which carbon moves from one part of the planet to another.
What is the biosphere?
Living things - plants and animals a
interacting with carbon.
What is the atmosphere?
Gases surrounding the earth.
What is the hydrosphere?
The total amount of water on a planet.
What is the lithosphere?
The rocky outer part of earth.
What % of the planet’s biomass is made of carbon?
50%.
What % of our bodies are made of carbon?
18%.
What happens when carbon bonds with hydrogen?
It creates carbohydrates.
How do we obtain most of our carbon?
Through food.
What happens in the biosphere?
Photosynthesis creates carbohydrates.
How many tons of carbon are stored in the biosphere?
560 billion tons - 0.0012% of all the planet’s carbon.
Which biomes contain the most carbon?
Regions of high primary productivity such as tropical rainforests.
How much carbon is stored in the atmosphere?
750 Billion metric tons - 0.0017% of all carbon.
What are the two main gases that contain carbon?
Carbon dioxide and methane - greenhouse gases.
What has happened to the amount of carbon in the atmosphere?
Has increased by 36% in the last 100 years, due to climate change.
What is the pedosphere?
Soil.
What % of all carbon does it make up?
0.0031%.
What is peat made up of?
Organic matter, and 60% carbon.
What can peat become when buried over millions of years?
Coal.
What % of global carbon is stored in the hydrosphere?
0.0038%.
What is the size of the hydrosphere, compared to other stores?
50x more than atmosphere, 18% more than all terrestrial life forms combined.
What % of carbon in oceans takes carbonate?
90%.
What % of the world’s carbon is stored in the lithosphere?
99.9% - In rock, marine, sediment, and sedimentary rocks.
What is the flow of carbon between the atmosphere and the biosphere? (Gigatons)
Atmosphere - Biosphere - 110Gt/yr.
Biosphere - Atmosphere - 50Gt/yr.
What is the flow of carbon between the biosphere and the pedosphere?
60Gt/yr.
What is the flow of carbon between the pedosphere and the hydrosphere?
0.5Gt/yr.
What is the flow of carbon between the hydrosphere and the lithosphere?
0.5Gt/yr.
What is the flow of carbon between the lithosphere and the atmosphere?
7.5Gt/yr.
What is the flow of carbon between the atmosphere and the hydrosphere?
105Gt/yr.
What is the flow of carbon between the hydrosphere and the atmosphere?
102Gt/yr.
How long does it take for the long term carbon cycle to occur?
100-200 million years.
How do carbonic acids form?
From carbon dioxide + water vapour.
What does carbonation weathering lead to?
C02 being released to the atmosphere, and the hydrosphere.
What happens to carbon found in oceans?
It goes into the shells and skeletons of marine creatures, as calcium carbonate. Organisms die, and the remains of carbon build up in layers.
What happens to carbon in the ocean after it has been compacted?
It is converted into fossil fuels.
What is sequestration?
Atmospheric carbon being stored in a liquid or solid form in the lithosphere.
What happens to carbon when subduction occurs?
Carbon contained in rocks is released, and rushes back to the surface, returns to the atmosphere in volcanic eruptions.
How many tons of C02 is returned to the atmosphere when subduction occurs?
200 Million tonnes.
What are the key processes of the slow carbon cycle?
Carbonation, Sequestration, Tectonic processes.
Why is rainfall naturally acidic?
Because of carbon dioxide in the air, and fossil fuels.
What happens when rocks containing calcium carbonate come into contact with acidic solutions?
Carbon dioxide bubbles, HCL reacts to limestone, rainwater reacts, carves out areas on the rock.
How does acid rain accelerate chemical weathering?
It causes erosion in the materials it comes into contact with.
What are the first two steps of chemical weathering?
C02 is dissolved in water vapour, forms carbonic acid. Precipitation becomes naturally acidic. Carbonic acid reacts with rocks containing calcium carbonate through carbonation weathering.
What are the last two steps of chemical weathering?
Calcium carbonate is soluble in water, is carried away by runoff water. Soluble calcium carbonate is transferred to the ocean by river runoff.
What are the connections between the water and carbon cycle?
CO2 dissolved in water vapour, runoff of calcium carbonate, river runoff in the ocean.
What is the PH of pure water?
7.0.
What is the PH of natural precipitation?
5.6.
Why is the PH of precipitation lower?
Volcanic eruptions release C02 into the atmosphere. In the atmosphere, C02 combines with limestone to create carbonic acid.
Which other activities increase the concentration of C02?
Human activities such as burning fossil fuels.
What is Carbonation?
Precipitation becoming more acidic, because of volcanoes.
What happens when precipitation comes into contact with rocks like limestone?
Chemical weathering is caused, and acid rain. Calcium carbonate is converted into water vapour, as it’s soluble.
What happens in areas where limestone dominates the type of surface rock?
They experience carbonation weathering, which can lead to ‘karst landscapes.’
What happens to calcium carbonate after carbonation weathering?
Rivers and throughflow transport calcium bicarbonate to oceans. At the bottom of the ocean, large amounts of dissolved inorganic carbon accumulate to form carbonate sediments.
What is carbonate used by?
Marine organisms in the oceans, to make their shells.
Why does carbon accumulate at the bottom of the ocean?
Bicarbonate - As chemical weathering was being transferred by rivers into the ocean.
How does biological carbon accumulate at the bottom of the ocean?
From accumulation of dead marine organisms.
What is lithification?
Sediment compacting over millions of years to/from rocks. They make up the upper layer of the oceanic crust.
What do sediments at the bottom of the ocean contain?
Millions of gigatons of carbon, making it the largest store of carbon.
What happens to carbon in subduction zones?
Carbon sediments are converted into magma. This could result in volcanic eruptions, putting C02 back into the atmosphere.
How many tons of C02 are put into the atmosphere per year by volcanoes?
200 Million tons.
How do fold mountains affect weathering?
They force carbonate rich sediments and rocks upwards, carbonation weathering occurs after rocks are exposed to precipitation.
What is Photosynthesis?
The process by which plants use sunlight and carbon dioxide to produce carbohydrates.
Which organisms in the ocean photosynthesis?
Phytoplankton.
What is respiration?
The process in which organisms release C02 as a by product of using carbohydrates to release energy.
Which gases do animals release?
Carbon dioxide and methane.
What is combustion?
When fire burns organic matter.
How many tonnes of carbon moves through the fast carbon cycle each year?
1 million - 100 million metric tonnes.
Why is peat a store for carbon?
There is very little soil in peat bogs, preventing plants from decomposing, trapping carbon in peat.
What are the key processes of the fast carbon cycle?
Diffusion of C02 between atmosphere and ocean. Photosynthesis, respiration, and decomposition. Combustion - forest fires, fossil fuels.
What are the two types of diffusion?
Physical pump - inorganic. Biological pump - organic.
How does diffusion affect carbon?
Moves carbon dioxide from atmosphere to the ocean.
What is the physical pump?
Movement of dissolved C02 around the ocean.
How can C02 be moved around the ocean because of variations in ocean temperature?
Down swelling and Up swelling.
What is downswelling?
Carbon can be transferred from the surface to the deep ocean in areas where cold surface waters sink. Occurs in polar regions.
What is upswelling?
Carbon can be transferred from the deep ocean to the surface where deep waters rise - Occurs in equatorial regions.
What are the first two steps of biological pumps?
Diffusion of C02 into ocean surface. Photo plankton photosynthesises, uses a diffused C02, storing it in new biomass.
What are the next two steps of biological pumps?
As part of the ocean food chain, phytoplankton are eaten by zooplankton, eaten by other marine organisms. When organisms respire, they release C02, some of which passes back to the atmosphere.
What are the last two steps of biological pump?
Marine organisms die and sink to the seafloor, adding to carbon rich sediments on the sea floor. Over millions of years, organic, carbon rich sediment can form fossil fuels.
How does photosynthesis vary?
Seasonally, due to light intensity, wind speed, temperature and humidity.
What happens to plants in spring and autumn?
Spring - Plants draw in C02. Autumn - Plant growth stops. Plant matter decomposes, released C02 back to the atmosphere.
What is gross primary productivity?
Measures the uptake of carbon in photosynthesis, measured in grams of carbon per square metre per year.
How does GPP vary?
Depending on water availability, temperature and solar radiation.
Where is water availability highest?
In tropical rainforests, where uptake of carbon is the highest, water availability is the lowest, temperature is highest.
Where is GPP lowest?
At the equator.
Where does respiration happen?
In all living cells - plant and animal cells.
Where is energy released from?
Glucose, so all other processes needed so life can happen.
Where is C02 released into?
Into the atmosphere as a by product of respiration?
What are the first two steps of decomposition?
Plants and animals die and decompose. Decomposition carried out by organisms known as decomposers such as fungi and bacteria secrete enzymes which aid the breakdown of organic compounds.
What are the last two steps of decomposition?
Other organisms aid decomposition, as they feed on dead organic matter. Decomposition releases C02 and methane back into the atmosphere.
How do worms affect infiltration rates?
Worms create drainage channels, allowing rainwater to infiltrate into deeper layers of the ground, increasing infiltration rates.
What are the decomposition rates in tropical rainforests?
Dead plant material is decomposed quickly by fungi and bacteria on the forest floor - due to high temperature and moisture.
What are the decomposition rates in periglacial landforms?
Low decomposition rates, soil is infertile, temperature is too low.
What is combustion?
Releasing C02 into the atmosphere.
What are the main stores of carbon which combust?
Living matter - wildfires. Fossil fuels.
How many kilometres of the earth’s land area are burned by wildfires each year?
3-4 million km squared.
What % of total greenhouse gas emissions do wildfires account for?
20%.
How is climate change increasing the risk of wildfires?
A 1.5 degree rise in temperature could lead to a 40% increase in wildfires.
What are the key components required to start a wildfire?
Fuel - Vegetation. Climate and recent weather - warm and wet, after warm, dry, windy weather. Ignition.
What are the natural causes of wildfire?
Lightning, Volcanic material.
What are the human causes of wildfire?
Clear land for agriculture, dropped cigarettes, fireworks, campfires, arson.
Which locations don’t experience wildfires?
Places without vegetation - Ice sheets, desserts - they don’t have the fuel needed to start fire. Rainforests - Too wet. Fire resistant climates.
How is human activity changing areas experiencing wildfire?
Rainforests are being disturbed by human activity such as deforestation. Reduces natural fire resistance, creating a more flammable environment.
What were the causes of the Australia 2019 wildfire?
Record breaking temperatures, severe drought, strong winds, lightning strikes in drought affected forests.
What were the impacts of the Australia 2019 wildfire?
Sixty fires burning, 150 homes burned down, drought, 850,000 hectares of land burned.
What were the causes of the Lincolnshire wildfire 2022?
Defect of engine of combine harvester, dry summer. Hottest ever temperatures.
What were the impacts of the Lincolnshire wildfire 2022?
Firefighters’ resources reduced, funds were raised by the NFU to attack firefighters’ pumps to water tanks.
How is the risk from wildfires changing?
Fewer, more intense wildfires. Fires spreading to areas with more fuels and trees.
What are the solutions to wildfires?
Natural defences, planting more vegetation, so nature can defend itself, reduce C02 emissions.
What are the fossil fuels?
Coal, oil and gas.
How do fossil fuels form?
Over millions of years from burial of carbon rich sediments.
Where do oil and gas come from, compared to coal?
Oil and gas - carbon floor. Coal - peat.
What % of global energy is derived from fossil fuels?
85%.
What is the main major cause of climate change?
Burning of fossil fuels.
How much have global average temperatures risen by since 1880?
1 degrees Celsius.
Why has the change in C02 concentration occured?
Because of fossil fuels burning for energy. Fossil fuels contain carbon which plants have pulled out of the atmosphere through photosynthesis.
