The Carbon Cycle and Energy Sercurity Flashcards
what is the geological carbon cycle?
a natural, long-term cycle that moves carbon between land, ocean, and atmosphere
what does the geological carbon cycle involve and what does this create?
involves a number of chemical reactions which creates new stores which trap carbon
how do chemical processes maintain a dynamic equilibrium?
- volcanic eruptions lead to a rise in temperature and hence increased evaporation/ moisture in the air
- increased acid rain weathers rocks and creates bicarbonates which are deposited as carbon on ocean floor
how is a state of dynamic equilibrium maintained in the geochemical carbon cycle?
carbon production and absorption are balanced
what do biological and chemical processes determine in the carbon cycle?
how much carbon is stored and released
what are the four processes involved in the biogeochemical carbon cycle?
- photosynthesis
- respiration
- decomposition
- combustion
how is photosynthesis involved in the biogeochemical carbon cycle?
removes CO2 from the atmosphere for plant growth
how is respiration involved in the biogeochemical carbon cycle?
releasing CO2 into the atmosphere
how is decomposition involved in the biogeochemical carbon cycle?
breaking down organic matter releasing CO2 into soil
how is combustion of biomass and fossil fuels involved in the biogeochemical carbon cycle?
releasing CO2 into the atmosphere
what do biogeochemical processes do for the carbon cycle?
continuously transfer carbon from one store to another
another word for carbon production?
outgassing
another word for carbon absorption?
sedimentation
examples of outgassing? (3)
- volcanism
- metamorphism of carbonate rocks at a subduction zone
- calcium carbonate deposition
example of sedimentation? (3)
- animal skeletons/ shells compact to form limestone
- decaying vegetation into coal
- sands and clays from rivers compact to form sandstone/ shales
how is carbon absorbed through sedimentation?
shells and skeletons of marine creatures extract carbon from seawater and phytoplankton. their remains accumulate on the seabed whereby the process of diagenesis, they compact into inorganic limestone.
what is diagenesis?
the long-term process by which sediments are changed into sedimentary rocks
how is carbon produced through outgassing?
volcanic activity at subduction zones causes gases such as CO2 to be released
why is so much CO2 released through volcanism?
CO2 is the least soluble of volcanic gases and so is degassed earlier than others and so are abundant
what is the largest carbon store?
the mantle
what is the largest known carbon store?
sedimentary rocks
what are carbon fluxes?
the exchange between stores of carbon
what is the biological carbon pump?
the process by which marine organisms sequester carbon from the ocean surface and convert it to organic matter
what do phytoplankton do in ocean carbon cycling?
photosynthesis, removing carbon from atmosphere and into the food web
what is the marine carbon pump?
the process of carbonate material accumulating on the seabed. occurs in the deep ocean
what is the physical carbon pump?
diffusion and transfer of CO2 in ocean currents. it occurs in the deep ocean and is global
what does the thermohaline circulation do in carbon cycling in oceans?
maintains the physical carbon pump by locking carbon in the deep ocean.
how does the thermohaline circulation lock carbon in the deep ocean?
- cold, saline water is more dense and so sinks
- warm water is drawn down from the surface
- water is drawn across from the Tropics
- cold water is drawn up to be warmed