Biogeochemical Carbon Cycle- Fast Cycle Flashcards
What is the formula for photosynthesis?
Carbon dioxide + water ——-> Glucose + oxygen
Sunlight
How do terrestrial plants store carbon?
Land based primary producers (produce own food) - tree or plant - sequester carbon through photosynthesis
What is the formula for respiration?
Glucose + Oxygen———-> Carbon dioxide + water + energy
How much more carbon is taken in by plants then released by respiration?
1000 times more CO2
How does plants exchange of carbon fluctuate?
Has seasonal pattern meaning there is higher CO2 concentrations in Northern hemisphere winter when less photosynthesis
What is happening to total CO2 in the atmosphere over time?
Increasing
When do peaks in CO2 in the atmosphere occur?
When northern hemisphere in winter due to little photosynthesis
When do troughs in CO2 in the atmosphere occur?
In Northern hemisphere summer when trees and vegetation are photosynthesising
What factors can lead to total CO2 in the atmosphere to increase?
Burning fossil fuels
Deforestation _ not storing from photosynthesis
Volcanic eruptions
Forest fires
Increasing population/ urbanisation
What are some examples of phytoplankton?
Cyano bacteria
Green algae
Where do phytoplankton exist?
In the surface waters of the oceans where they carry out photosynthesis (carbon taken from sea so more can enter from atmosphere)
What might happen to phytoplankton over time? (Natural)
Other living organisms feed on the phytoplankton and use the carbon in the calcium carbonate of their shells and skeletons (biological pump)
What are the three types of pump in the ocean carbon cycle?
Biological pump
Geological pump
Physical pump
What is the biological pump?
Transfer of carbon between organisms in the food chain
What is the geological pump?
Transfer of marine organisms into sedimentary rocks farming oil/gas or limestone
What do water currents do to carbon enriched water?
Transport it along the sea floor
What is the physical pump?
Upwelling which can occur bringing CO2 and nutrients to the surface water
what are some other names for thermohaline circulation?
Global conveyor belt
Gulf stream (north atlantic conveyor)
What are surface and deep ocean currents dirven by?
Temperature (thermo) and salinity (haline) and the differences between these for different oceans
What type of water does CO2 dissolve more readily into?
Cold water
Where are important carbon sinks for cold water CO2 absorption?
Southern ocean around Antarctica
What are decomposers also known as?
detrivores
What are some examples of. detrivores?
worms and fungi
What do decomposers do?
break down DOM into CO2, nutrients and water
What happens to the carbon form broken down DOM?
reclaimedand put back into the cycle so other living organisms can use it through soils
How much of global carbon do soil store?
20-30%
What local circumstances affect sequestration or emmittance of carbon?
climate
soil type
soil management
What are some exampels of soil stores of carbon?
long-term decomposition process creates humus carbon-rich soil (60%)
Long term carbon storage in frozen soils have flipped from storage to source as they melt (permafrost)
What is the name of the laboratory in Hawaii that measures concentration of atmospheric carbon?
Mauna Loa observatory
Is the Tundra typically a carbon sink or emitter?
Carbon sink
What are the main carbon stores in the Tundra carbon cycle?
Soils and plant biomass
When is most carbon absorbed in the Tundra?
In the short growing period when plant photosynthesis is greater than carbon respired by plants + soil into atmosphere
How much carbon is contained in the Northern permafrost region?
1460-1600 billion metric tons of organic carbon 2x as much as atmosphere
What is the main threat to the Tundra carbon cycle?
Climate sensitivity
warming causes carbon rich permafrost to thaw releasing CO2 and CH4 creating a feedback loop creating more melting
What is the CO2 flux from permafrost melting? (Tundra pg amount)
0.3 to 0.6 pg C
What % of carbon is stored in the surface soil? (Tundra)
65-75% (0-3 meters)
What % of carbon is stored in the deep soil? (Tundra)
25-30%
(>3m)
How much carbon is placed in deep loess deposits in the Yedoma region? (Amount)
327-466 pg C
How many giga tons of carbon are stored in the amazon rainforest?
up to 200
How much carbon is added to the amazon rainforest store per year?
1.5 billion tons
How many trees are in the amazon rainforest?
3 billion
How much do the trees in the amazon account for global carbon emission on land?
1/4
What is happening to the amazon rainforest carbon sink?
diminishing as tree growth and absorption rate are plateauing
How much has the amazon store of carbon reduced since 1990?
30%
What are the main stores of carbon in the amazon rainforest?
Roots
Micro-organisms
Soil fungi
plants
What ways will the carbon cycle in the amazon rainforest be affected by climate change?
Loss of peat soil could tip rainforest into being carbon emitter
Changing weather and rainfall causing droughts and wildfires which kill organisms
How much carbon was released by a forest fire in the amazon in 2021?
3.6 billion metric tons
How does drought affect the amazon? (carbon cycle)
In severe droughts, when the forest loses more water to evaporation than it receives from rain, the trees begin to die
What has research shown about tree death in droughts in the amazon?
For every three trees that die due to drought in the Amazon rainforest, a fourth tree, even if not directly affected by drought, will also die,
What is the problem with trees dying form drought and forest fire in the amazon? (carbon cycle)
burning of trees releases carbon into the atmosphere
If all trees die there won’t be a store for carbon
What are some greenhouse gases?
Carbon dioxide (natural)
Methane (natural)
CFCs (chlorofluorocarbons) (Human)
Nitrous oxide(NOx. + human)
How do human activities affect the carbon cycle?
Change the rate of movement of carbon through the cycle- causing dynamic equilibrium to be unbalanced
What typical way do humans affect the carbon cycle?
Moving much of the carbon in the cycle into the atmosphere
What ways can humans cause changes to photosynthesis?
Deforestation
Afforestation
Marine pollution
Algae
How does deforestation affect the carbon cycle?
Humans have cut down vast amounts of forest cover which reduces the movement of carbon from the atmosphere into the biosphere/ biomass
How does afforestation affect the carbon cycle?
Humans can increase the rate of transfer from the atmosphere by planting trees/ shrubs although the rate of afforestation is not great compared to deforestation
How many trees would a human need to plant to be carbon neutral?
7 in their life time
How does marine pollution affect the carbon cycle? (Photosynthesis)
Toxins in the oceans mean that ocean organisms are dying (phytoplankton)
Without these tiny (trillions of them) organisms, less of the ocean CO2 is being stored at the bottom of the ocean in their bodies
What are a type of phytoplankton?
Diatom
What is the trend with diatoms and CO2?
As number of diatoms falls and is set to continue falling the CO2 concentrations are expected to continue to increase
How can algae affect the carbon cycle?
Algae live under the sea ice in the Antarctic/ southern ocean
During photosynthesis they absorb carbon
Krill east algae and carbon krill ingest from algae is defecated out sinking to sea floor
How are humans affecting algaes part in the carbon cycle?
Human induced climate change is causing melt of the Antarctic sea ice, so algae is reducing, so less CO2 is being removed from the oceans
What 2 types of respiration are there?
Aerobic
Anaerobic
What is aerobic respiration?
With oxygen
Waste- CO2
What is anaerobic respiration?
No/ little oxygen
Waste- methane
How long does carbon last in the atmosphere?
100-200 years
How long does methane stay in the atmosphere?
12 years (more potent)
What changes can occur to aerobic respiration?
DOM contains vast amount of carbon
DOM decomposed by fungi and bacteria slowly releasing CO2
Farmers ploughing aerates soil increasing oxygen content
This allows decomposers to decompose DOM more rapidly releasing more CO2 into atmosphere more rapidly
What ways can human activities increase anaerobic respiration?
Creation of paddi fields
Creation of land fill sites
Sedimentation in reservoirs
Livestock intestines
How does creation of paddi field increase anaerobic respiration?
Rice likes to grow in boggy water logged soils with title oxygen content
How does creation of landfill increase anaerobic respiration?
Air squeezed out to save space meaning little oxygen present
How can methane form livestock intestine be reduced?
Feeding particular food (red seaweed reduces methane to around 0%)
Breeding individuals who release less
How many cows are there on the planet?
1.6 billion which release 100kg of carbon each (equivalent to burning 1000 litres of petrol per cow)
How much does cow methane make up of total GHG emissions?
18%
How much more potent is methane from carbon?
23 times
What activities can decrease anaerobic respiration?
Draining water logged fields
Draining march land for farming
Putting drainage in peat bogs
If you decrease anaerobic respiration and methane what do you increase?
Aerobic respiration and CO2
What is the problem with land drainage? (Carbon/ water cycle)
Affects water cycle (loss of store) and ability for soil to store carbon (fires)
What does combustion relate to?
Humans burning fossil fuels- coal oil gas
How is the dirtiness of fossil fuels ranked?
Dirtiest= coal
Medium= oil
Least= gas
How much of the global CO2 emissions come from burning coal?
44%
What sort of things are fossil fuels used for?
Power cars planes and ships
Used to generate electricity for homes and factories
How is concentration of CO2 increased in the ocean?
Humans increase CO2 in atmosphere because ocean absorbs CO2 the concentration in the ocean increases
What happens when CO2 enters the ocean?
Dissolves/ exolves (separates out of solution) and forms a weak carbonic acid
What organisms are affected by carbonic acid?
Those with calcium carbonate exoskeletons like corals
What is biomass?
Any organic material that comes from plants and animals that was alive at some point
What does biomass contain?
Stored energy from the sun and starts with a producer (plants)
Carbon
How much of humans are carbon?
16%
Do humans intentionally move biomass?
No, but human activities unintentionally move huge amounts of biomass
What human activities move huge amounts of biomass?
Cut down trees which damage soil/ allows soil erosion
Change where marine organisms live (aquaculture)
Increase biomass by composting or mulching soil
Add biomass to ocean by emptying sewage (bad)
Why is deforestation so bad for the carbon cycle?
As it is the biggest land store of carbon (450 gt)
Where is the fastest warming area of the globe?
Siberia 3*c per year
How much would methane in the atmosphere increase if the permafrost melted?
10 times
What is the feedback loop for methane and permafrost?
Climate change caused by increased CO2, causes permafrost to melt and slide into bottom of numerous lakes in tundra, anaerobic decomposition, forms methane bubbles out of lake (repeat)
What is the effect of reduced carbon in plant biomass?
Less carbon in DOM
How do humans affect the amount of carbon plants can store?
Deforestation
Conversion of land to farmland
How does reduced carbon in DOM affect the soil?
Carbon from dead plants woven into soil by decomposers less vegeation on means less carbon into soil
What does NPP stand for?
Net Primary Productivity
How is NPP measured?
Grams/square metre/year
What is net primary production an important measure of?
Growth of plants and therefore conversion of atmospheric CO2 into carbon stored in plants
How much should anthropogenic CO2 increase photosynthesis and NPP?
63% by 2100
What is the limiting factor for plant growth? (NPP and photosynthesis increase)
Nutrient availability (nitrogen and phosphorus) meaning growth rate limited to 20% in tropical rainforests, savannahs, boreal forests and tundra
What habitats have the highest and lowest NPP value?
Tundra lowest- 0.5-1
Tropical forests- 16-23.1
Where is most carbon stored in the tundra?
Permafrost
Where is most carbon stored in the boreal forest?
Soil
Where is most carbon stored in the temperate forest?
Biomass above and underground (roots)
Where is most carbon stored in the temperate grasslands?
Soil
Where is most carbon stored in the deserts and dr shrubland?
Soil
Where is most carbon stored in the savannah and tropical grasslands?
Soil
Where is most carbon stored in the tropical forests?
Above ground biomass
Where is most carbon stored in the wetland/peatland?
Soil
Where is most carbon stored in the oceans?
Deep ocean
What are the main threats to global habitats and carbon emissions?
Rising temperatures
Fires,
Logging
Mining
Historic losses
Degradation by livestock and crops
Deforestation
HEP
Drainage
Fuel and fertiliser use
Degrading coastal zones
What can carbon stored in the ground influence?
Soil health -ecosystems and their productivity
What is productivity of soils influenced by?
Level of organic carbon
Lack of nutrient rich organic carbon matter can lead to soil erosion
WHat are the outputs of carbon from soil?
Loss by leaching
Loss in runoff
Falls out as tissues die
What are some inputs of carbon to soil?
Dissolved in rainfall
Weathered form rock
What are some examples of soil degradation?
Deforestation in the amazon and impact on soil fertility
Changes to climate- desertification in the Sahel region of Africa/ southern Spain
