What is the biological carbon cycle?
‘Fast carbon cycle’ concerned with biomass, and the atmosphere
What is the geological carbon cycle?
‘slow carbon cycle’ concerned with rocks, sediment, and hydrology
What are the three main stores of lithospheric carbon within the geological cycle?
Limestone - comprised of ancient dead organisms from 1000-500 years old.
Coal - Peat bog biomass which as been compressed to change its chemical composition.
Shale - Comrpessed dead organisms become shale layers within rock.
What are the main tranfers (fluxes) within the geological carbon cycle?
weathering processes
volcanic outgassing - releases 0.25 - 15 Gigatonnes of carbon into the atmosphere annually.
What are the three main weathering processes?
Mechanical weathering - Freeze-thaw weathering
Biological weathering - roots and burrowing animals
Chemical weathering - Acid rain.
What are the key stages of negative feedback concerning the geological carbon cycle?
- Increased volcanic activity
- loss of carbon in rock
- rising temeprature fom CO2
- more air uplift
- more chemical wethering
- more ion decomposition
- mroe carbon in rocks.
What are the three ways in which the biological carbon cycle sequesters carbon in oceans?
The biological pump
The carbonate pump
the physical pump
What is the process of the biological pump?
- Phytoplankton photosynthesise
- Phytoplankton are eaten by zooplankton
- Zooplankton are eaten by bigger animals, and are then sequestered as marine snow.
- marine snow then floats to deeper ocean
What is the process of the carbonate pump?
Phytoplankton proguce inorganic carbon in the form of shells. This then sinks when the creature dies to the bottom of the ocean.
What is the process of the physical pump?
Warm water cools because of thermohaline circulation, and absorbs CO2.
This then allows the water to sink and also sink the CO2 it has absorbed.
What are the Himalayas made of and why?
Limestone from ancient sequestration of marine organisms.
What is the overall process of the slow carbon cycle?
- Terrestrial carbon exists in mantle
- Volcanos release CO2 into the atmosphere through outgassing.
- Acid rain /carbonic acid weathers sediment.
- rivers transport newly carbonated sediment to the ocean, and forms a new layer of sediment.
- subduction then causes carbon to return to the mantle, while releasing CO2 in the process.
What is the process of thermoline circulation?
- Polar ocean - cold sinking water
- travels to arctic to recharge into cold, salty water.
- travels towards the equator and heats up and rises.
- travels along globsl currents before reaching the arctic again.
(This process takes 1000 years)
What factors influence the speed of decomposers?
- climate - high temp. = fast
- pH in soil = slightly acid to neutral pH
- human activity = ploughing = good.
What are the largest global stores of terrestrial carbon?
The rainforest = biomass
boreal forest = humus
What is the greenhouse effect?
It’s the process where:
- Radiation from the sun reaches earth
- It either, bounces off the atmosphere, is absorbed by the earth, is reflected by the earth. It may then be re-emitted as infrared radiation.
- This then leads greenhouse gases to develop within the atmosphere, and stabilise earth’s atmospheric composition.
What are the four processes what the Carbon Cycle and Greenhouse effect stabilise?
- Temperature
- Atmospheric composition
- Soil acidity
- Precipitation levels
How do the Carbon cycle and Greenhouse effect stabilise global temperature?
Heat is concentrated at the equator by the sun, and then is distributed to the poles by wind. If there is regular CO2 levels caused by solar energy and non-human factors, temperature will remain stable.
how do the Carbon Cycle and Greehouse effect stabilise precipitation levels?
Precipitation is dictated by atmospheric pressure. pressure is determined by temperature and therefore the wind cells.
How do the carbon cycle and the greenhouse effect stabilise atmospheric composition?
In order for phytoplankton and organisms to sequester carbon, they require the right chemicals in the air in order to complete the reaction of photosynthesis.
How do the carbon cycle and the greenhouse effect stabilise healthy soil carbon storage?
Allow for healthy soils to be maintained:
- porous, dark, and crumbly.
- containing organisms.
- retains moisture.
What is the annual and seasonal difference in the emission of carbon globally?
In Summer there is far less carbon in the atmosphere, due to more photosynthesising done by organisms and plants.
How has anthropogenic influence impacted the carbon cycle?
atmospheric carbon = increased
vegetation carbon = decerased
fossil fuels = decreased
land carbon = increased
ocenic carbon = incerased
How has human interaction impacted the arctic?
4 degree heating in the last 50 years which as led to 2X the rate of melting.
