The Carbon Cycle and Energy security - Set 1 Flashcards
1
Q
Why is carbon important
A
Major building block for all life on earth - regulates climate making it warm enough to survive
2
Q
Where is carbon stored
A
- Rocks, plants and oceans
- Present in atmosphere, biosphere, lithosphere, hydrosphere
3
Q
What is a flux
A
Transfer of carbon between stores
4
Q
biogeochemical carbon cycle
A
How much of carbon available on earth’s surface is stored or released at any one time
5
Q
Geologically derived carbon
A
- CO2 loss from air through transformation of silicates to carbonates
- CO2 loss via calcium carbonate deposition
- Release of CO 2 into the atmosphere by volcanism
6
Q
Biologically derived carbon
A
- Carbon forms animal shells
- animals die their shells form limestone
- Decaying vegetation forms coal strata at margins of land and sea
7
Q
Slow carbon cycle
A
Cycling of carbon between land and sea through erosion and deposition over very long timescales and at continental scales
8
Q
How does chemical weathering increase carbon stores
A
- Acidic water breaks down rock such as chalk and limestone - carbonation solution releases carbon from rock stores
- 300 million tonnes of carbon transferred from rocks annually
9
Q
Roles of rivers in the carbon cycle
A
- Calcium bicarbonate transferred via overland flow into rivers where it becomes part of the solute load - carbon can be locked in rocks in the ocean for 100 million years
10
Q
How does volcanism maintain an equilibrium
A
- Huge volumes of carbon constantly moving through geological processes
- Volcanic activity increased emissions in Hawaii by 12%
- Geothermal areas etc also produce CO2
11
Q
Which Biomes are the most productive
A
Tropical forests, Savannah and grasslands account for 50% of global net primary production
12
Q
How do Carbon fluxes vary diurnally
A
During the day, fluxes are positive whereas during the night they are negative
13
Q
How important are tropical rainforests as a terrestrial store of carbon
A
- One of largest stores in earth - sequesters 17% of all terrestrial carbon - e.g. Brazilian nut trees make up just 1% of the Amazons trees but store 50% of it’s carbon
14
Q
Biological carbon pump - Marine Phytoplankton
A
- Absorb carbon through photosynthesis and make up half of the globes biomass
- Carbon is passed up the food chain before being released back into the ocean
- Phytoplankton sequester 2 billion metric tonnes of carbon annually
15
Q
Carbonate carbon pump
A
- Marine organisms use calcium carbonate to make shells e.g. lobsters - when die the carbon become part of deep ocean current which slowly builds up on the ocean floor forming limestone e.g. white cliffs of dover
16
Q
Physical carbon pump
A
- Colder the water = more CO2 is absorbed - e.g. deep oceans CO2 concentration is 10% higher then shallow areas
- Currents such as the North Atlantic Drift move war water from the tropics to cold areas where more CO2 is absorbed
17
Q
Thermohaline circulation
A
- Current begins in the Arctic where it is recharged
- Current splits into the Indian ocean and the Pacific where water warms and rises before returning to the Arctic
18
Q
Permafrost as a store of Carbon
A
- More melting = more methane produced = positive feedback loop
19
Q
Wetlands and peatlands as a store of Carbon
A
- Formed during the Holocene period - cover 3% of earth’s land surface and store 2 times more Carbon than Earths forests
20
Q
Biological carbon
A
- 30% of Carbon stored in the soils
- Carbon transferred from plants to soil through Leaf litter - this is then broken down and released back into the atmosphere
21
Q
What is Humus
A
- Formed from long-term decomposition - made up of 60% Carbon
22
Q
Where is carbon cycling most active
A
- Topsoil horizons
- Stabilised Carbon stored in the deeper layers of soil
- In permafrost regions 61% of Carbon is stored deeper then 30cm
23
Q
What is Pyrogenic Carbonaceous matter
A
- Formed from biomass that has been burned and carbonised during wildfires - it is a long term Carbon store
24
Q
How is the capacity of soil to store organic carbon determined
A
- Climate = rapid decomposition at high temps - Arid soils hold 30 tonnes of carbon a hectare compared to 800 tonnes in cold areas
- Soil type = Clay soils have a high carbon content as it protects the carbon from decomposition
- Management of soils = Soils losing 0.8 billion tonnes of carbon annually due to land changes
25
Why is the greenhouse effect vital
Temps on earth would be 16 degrees lower without it
26
How does the greenhouse effect work
- Sun send solar energy towards earth
- some absorbed and some reflected back by greenhouse gasses
27
Greenhouse gasses
- CO2 = 89% of greenhouse gasses produced
- Methane = 7% of greenhouse gasses produced but 21x more powerful than CO2
- Nitrous oxide = 3% of gasses produced but 250x more powerful than CO2
- Halocarbons = 1% of gasses produced but 3000x more powerful than CO2
28
Anthropogenic
Influenced by humans
29
Why is the Holocene often referred to as the Anthropocene
Due to the profound changes to the earth caused by Humans - CO2 emissions increased by 40% in last 300 years
30
Difference between the Greenhouse effect and the enhanced Greenhouse effect
Less heat escapes due to increased greenhouse gasses in the earths atmosphere under the enhanced greenhouse effect
31
Evidence of rising temps
20 of hottest years on record happened in the last 22 years
32
How does increase in CO2 contribute to the enhanced greenhouse effect
- Acts like a blanket - absorbs heat radiation from earths surface - this blanket is getting thicker with more CO2 being produced
- Concentration of Carbon was 280 ppm before burning of fossil fuels but it is now 400 ppm - led to a 1 degree temp rise
33
How is heat distributed across the planet
- Hottest temps found on the equator where the suns radiation is the most direct - temps then cool the further you travel from the equator
34
What effects the natural distribution of Temperature
greenhouse gasses
35
How is rainfall distributed across the planet
Most intense along the equator - tropics area areas of low rainfall
36
What effects the natural distribution of rainfall
Regional and seasonal variation occur due to the effects of relief and the migration of global pressure patterns and wind systems
37
Photosynthesis
- 2 types - oceanic and terrestrial
- Plants sequester 120 Gt annually whereas Phytoplankton only 15 Gt - terrestrial sequesters more
38
Why is Carbon Sequestration high in tropical rainforests
Optimum conditions for plant growth
39
Why is Carbon Sequestration so high in coral reefs
Grow in warm, tropical, shallow waters
40
Why is Carbon sequestration so low in Deserts
Lack of plants in the landscape = very little photosynthesis
41
Factors that affect carbon sequestration in Ocean ecosystems
Anything that effects the levels of Phytoplankton's in the oceans
42
Factors that affect carbon sequestration in Terrestrial ecosystems such as tropical rainforests
Land use changes, deforestation and wild-fires - regrowing of trees can increase carbon sequestration
43
Arctic Algae blooms
- Melting sea ice exposes more water to sunlight = increased photosynthesis by phytoplankton which leads to the algae blooms
44
Why is Carbon important for soil health
Gives soils their water retention capacity, structure and fertility - improves resilience to both warmer and colder conditions - However Carbon can also cause soil erosion
45
Healthy Soils
- Dark, crumbly and porous
- Contain more carbon or organic matter
- Organic carbon is more concentrated in the surface soil layer as easily eroded small particles = increases the risk of soil erosion
46
Carbon pathways
- How Carbon moves from one store to another
- e.g. Decomposition of plant material in wet soils = more CO 2 is released = more global warming
47
Fossil fuel combustion - Balance
- Source = adding carbon into the atmosphere
- Sinks = Removing carbon from the atmosphere
48
Fossil fuel combustion - Implications for climate change
- Land temps increased in Europe more than the global average
- Precipitation projected to increase in northern Europe and decrease in Southern Europe
49
Fossil fuel combustion - Arctic amplication
Arctic is warming twice as fast as melting - elting sea ice and reduced snow cover allows for more water to be visible and more shrubs to grow which lower the albedo of the area
50
Fossil fuel combustion - Implications on the Hydrological cycle
- Europe's water comes from melting glaciers - Eastern alps will be ice free by 2100 - also leads to more sediment in water as the glaciers melt
- River discharge patterns changing = more flooding and drought
