ELSS-Carbon Flashcards
What is the importance of the carbon cycle?
-Used by humans for energy
-‘building blocks of life’
-used for photosynthesis to be turned to O2 as CO2 is toxic to humans
What are the consequences of disruptions to the carbon cycle?
-Sea level rises (80cm by the end of the century)
-Forest fires become more frequent and areas losing the amazon could feel the greatest impact
-Food shortages - wheat yields have decreased by 40% in Africa
Is the global carbon system an open or closed system?
Closed as the amount of carbon on the earth doesn’t change, it only changes form
What is an example of an open carbon system?
Forest - Trees can be cut down or die, and leave the carbon system Any system that carbon can leave or enter is open.
What are the 3 largest global carbon stores?
1st: Lithosphere - stored as fossil fuels and in rocks, the lithosphere stores most of the carbon on Earth
2nd: Oceans - stored as dissolved carbon and calcium carbonate in the shells of marine life. Only 4% of carbon is stored near the surface
3rd: Biosphere - stored in organic molecules in living or dead plants and animals. Decaying releases CO2 to the atmosphere.
4th: Atmosphere - Stored as the gas CO2
What are key fluxes in the carbon cycle?
-Precipitation
-Respiration
-Carbon sequestration
-Photosynthesis
-Weathering
-Decomposition
-Combustion
How does the carbon cycle influence precipitation?
An increase in CO2 levels have led to a dramatic increase in the acidity of seawater and therefore rainfall.
What is the role of respiration in the carbon cycle?
-6 O2 + C6H12O6 —> 6 CO2 + 6 H2O + ATP
-Plants and animals absorb oxygen to provide energy which is needed for metabolism and growth
-The volume of carbon exchanged by respiration and photosynthesis each year is 1000x higher than through the slow carbon cycle
-Stays in balance with photosynthesis (biosphere -> atmosphere -> biosphere.)
What is the carbon sequestration physical pump in the carbon cycle?
Physical inorganic pump:
-CO2 enters the ocean from the atmosphere by diffusion.
-Surface ocean currents then transport the water and dissolved CO2 towards the poles where it cools, becomes more dense and sinks
-Downwelling carries dissolved carbon to the oceans depths where individual carbon molecules remain for centuries
-Eventually deep ocean currents transport the carbon to areas of upwelling causing the water to rise and CO2 to diffuse into the atmosphere
What is the carbon sequestration biological pump in the carbon cycle?
Biological pump:
-Marine organisms (phytoplankton) combine sunlight, water and dissolve CO2 to produce organic material
-This causes carbon to be locked in the sediment on the ocean floor or decomposed to release CO2 into the ocean
-Some crustaceans extract carbon and calcium ions from sea water to manufacture shells and skeletons
-Most carbon-rich material ends up on the seafloor undergoing lithification to form chalk or limestone
What is photosynthesis?
-6 CO2 + 6H2O —> 6O2 + C6H12O6
-Using the sun’s energy to cover the light energy into chemical energy for the formation of glucose and growth in plants
-O2 is released balancing respiration
What is weathering?
*Check coasts section
What is decomposition?
Bacteria or fungi break down dead organic matter, extracting energy and releasing CO2 into the atmosphere.
This occurs faster in warm humid environments (places with rainforest).
What is combustion?
-Organic material earths or burns in oxygen, releasing CO2 as well as sulphur dioxides and nitrogen oxides
-Usually occurs from human activity (deliberate firing of forest & combustion of fossil fuels) but occurs naturally in forest fires
-This increases the amount of CO2 in the oceans and atmosphere adding to the greenhouse gas effect
How does temperature influence carbon moving between the atmosphere and oceans?
Increase in temperature - speeds up diffusion of CO2 out of the ocean but slows absorption into the ocean from the atmosphere.
As temperatures increase due to global warming more carbon will be released from pumps resulting in a downwards spiral.