EQI 1 Flashcards
what is carbon and where is it found?
the 6th most common element and it is found in the:
- atmosphere (carbon dioxide)
- hydrosphere (dissolved CO2)
- lithosphere (carbonate in limestone and fossil fuels
- biosphere ( living and dead organisms)
what is negative feedback?
no change
what is positive feedback?
change
what are the stores of carbon?
LONG TERM
earth’s crust - 100,000,000 GT
ocean’s - 38,000 GT
SHORT TERM
fossil fuels - 4,000 GT
soils - 1,500 GT
atmosphere - 750 GT
plants - 560 GT
what are the fluxes of carbon?
photosynthesis - 120
ocean uptake - 92
ocean loss - 90
soil and plant respiration - 60
litterfall - 60
burning FF - 6
deforestation - 0.9
volcanoes - 0.1
what are the 4 biochemical processes?
photosynthesis
respiration
decomposition
combustion
what is the geological carbon cycle
it is the biggest store but the SLOWEST
what are the stages of the geological carbon cycle
1) the movement of carbon from the atmosphere to the rocks begins with rain
2) carbon combines with water to form carbonic acid which chemically weathers and releases calcium, magnesium and sodium
3) in the ocean, the calcium ions combine with biocarbonate ions to form calcium carbonate
4) sedimentation - accretion of sediments occurs
5) then volcanic outgassing returns CO2 to the atmosphere.
what is limestone?
A sedimentary rock, formed at the earth’s surface
what are the uses for limestone?
- addition of lime to new zealand soil reduces it’s acidity, aiding New zealand agriculture
- cement is made by mixing limestone with clay minerals
- petrol and gas fields are contained in limestone because it has lots of holes in it
what is diagenisis?
the hardening of loose sediment into sedimentary rock - carbonate sediments (skeletons) become limestone
what is the biological carbon pump?
the fastest part of the carbon cycle - hours/days
- the oceans absorb CO2 from photosynthesising phytoplankton, stored in their bodies and passed into food chains
how does carbon go from biological to geological carbon cycle?
when zooplankton dies and sinks to the ocean floor they create a carbon rich sediment called calcareous ooze
what is the thermohaline conveyor?
a global system of deep ocean currents driven by differences in water temperatures and salinity causing denser, colder and saltier water to sink and circulate around the globe.
- distributes heat around planet
what is the gulf stream?
a powerful warm ocean currents that flows north along the eastern coast of the US
what would the weakening of the gulf stream do
it would alter weather patterns, it would also lead to a lack of nutrients reaching the phytoplankton and the death of sealife.
how much carbon do phytoplankton sequester?
10-15 GT
how much carbon do terrestrial photosynthesis sequester?
100-120 GT
what are the terrestrial stores of carbon?
primary producers –>
primary consumers –>
secondary consumers –>
decomposers
what is peat?
carbon rich wetlands which occupy 3% of the global land surfaces
- the waterlogged conditions prevent plant material from fully decomposing and peat is formed by the partially decayed material
why is peat important?
they have a NET COOLING effect on the climate, reduce flood risk and support biodiversity
what are the different stores of carbon?
- tropical rainforests (25%-40%)
- mangroves (10-15%)
- boreal forests (700GT)
- tundra
- wetlands (500-700GT)
what is the greenhouse effect?
carbon dioxide and gases in the atmosphere stop some radiation from the earth’s surface escaping into space
by retaining the heat, the earth’s surface is kept at 16 degrees so it can sustain human life
what is the enhanced greenhouse effect?
the concentration of several greenhouse gases in the atmosphere have increased by 25% since 1750.
- as global temps increase so do water vapour levels in the atmosphere = greater evaporation thus condensation leading to increased cloud cover which traps heat
