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Earth Life Support Systems - Coggle Diagram
Earth Life Support Systems
why is carbon important?
building block of life on earth
necessary for photosynthesis
in human DNA and bones
stored in rock, sea floor sediment, ocean water, the atmosphere and biosphere
key terms
adiabatic expansion: when a parcel of air rises as air pressure decreases causing an increase in volume and a decrease in temp
dynamic equilibrium: a system displaying unrepeated average states through time
Carbon cycle
stores biggest to smallest: lithosphere, oceans, biomass, atmosphere
key processes involved
respiration: reverse of photosynthesis
decomposition: decomposes organisms such as bacteria and fungi breakdown dead organic matter extracting energy and releasing CO2
photosynthesis
combustion: releases CO2 as well as other gases
oxidation
weathering: carbonation releases carbon from limestones to streams, rivers, oceans and atmosphere
carbon sequestration: in the oceans
physical (inorganic) pump: involved the mixing of surface and deep ocean waters by verticle currents creating evenly distributed carbon. Carbon rich water rises to the surface and CO2 diffuses back into the atmosphere
Biological (organic) pump:carbon is exchanged between oceans + atmosphere through the actions of marine organisms
sequestration of waste carbon
this is when carbon is captured and stored to avoid making its way into the atmosphere and to mitigate possible climate change
involves 3 stages
the CO2 is separated from power station emissions
the CO2 is then compressed and transported by pipeline to storage areas
it is injected into porous rocks deep underground where it is stored permanently
water cycle
processes of the water cycle
condensation: types of clouds
Cumuliform clouds: most often form when air is heated locally through contact with the Earth’s surface. Causes heated air parcels to rise freely through the atmosphere and expand due to the fall in pressure with altitude and cool. As cooling reaches the dew point, condensation begins and clouds form.
Stratiform or layer clouds: develop where and air mass moves horizontally across a cooler surface
Wispy, cirrus clouds: form at high altitude, consist of tiny ice crystals. they do not produce precipitation and therefore have little influence on the water cycle
transpiration
responsible for around 10% of moisture in the atmosphere
influenced by temperature + wind speed + water availability to plants
e.g deciduous trees shed their leaves in climate to reduce moisture loss through transpiration
dew point: the critical temperature when air becomes saturated and can hold no more water vapour
key terms (water)
evaporation: the process which liquid water is converted into a gaseous state
precipitation: moisture (rain,snow, hail, sleet) falling from clouds towards the ground
condensation: the phase change of water vapour to water (gas to liquid)
aquifer: a water bearing band of porous or permeable rock
transpiration: the evaporation of moisture from pores on the leaf surfaces of plants
evapotranspiration: combined loss of water at the surface through evaporation and transpiration
interception: rainwater stored temporarily on the leaves, stems and branches of vegetation which is evaporated and does not reach the ground surface
infiltration: the verticle movement of rainwater through the soil
ablation: the loss of ice and snow through melting, evaporation and sublimation
groundwater: water stored underground in permeable and porous rocks known as aquifers
stemflow: the flow of water along branches and stems of trees and plants to the ground
sublimation: the phase change of water from ice vapour
throughfall: rainfall, initially intercepted by vegetation, which drips to the ground
throughflow: water flowing horizontally through the soil to streams and river channels
percolation: the movement of surface and soil water into underlying permeable rocks
Case Study: Arctic
climate
mean annual precipitation is low
in the winter temperatures go below -40
8-9 months of the year the tundra has a negative heat balance with temperatures below freezing
permafrost: a thick subsurface layer of soil that remains below freezing point throughout the year
permeability: is low owing to the permafrost and the crystalline rocks which dominate the geology of the tundra in the arctic
relief: rock has been reduced to a gently undulating plain by erosion and weathering. Can contribute to water logging
Carbon
mainly stored as partly decomposed plant remains frozen in the permafrost
photosynthesis and NPP are low
mineral decomposition exert little influence on the water and carbon cycle
carbon store in biomass is relatively small
permafrost
functions as a carbon sink
global warming raised concerns of carbon becoming a source
outputs of carbon from permafrost have increased
snow cover may insulate some organisms and allow some decomposition to occur despite the low temperatures
during the growing season plants input carbon rich litter to the soil
accumulation of carbon is slow due to the low temperatures which slow down decomposition
water
limited transpiration due to the sparseness of vegetation cover
low rates of evaporation as most of the suns energy goes into melting the snow so the ground temperatures remain low. Surface and soil remain frozen
ponds and lakes during summer as a temporary store of liquid water (due to the permafrost)
limited groundwater and moisture stores as permafrost is a barrier to percolation and groundwater flow
small stores of moisture in the atmosphere due to low temperatures
management strategies used to moderate the impacts of the oil and gas industry
development of the north slope has often involved the deliberate destruction of permafrost. Protecting the permafrost minimising disruption to water and carbon cycles
buildings and pipelines on elevated piles to allow cold air to circulate beneath which will reduce the melting of the permafrost. However not sustainable in the long term.
insulated ice and gravel pads to protect the permafrost
drilling laterally beyond drilling platforms. new drilling of oil and gas to be accessed several kilometer from the drilling site
arctic council
Canada, USA, Denmark, Russia, Norway, Iceland, Finland. Sweden and indigenous
is the leading intergovernmental forum promoting cooperation, coordination and interaction among arctic states
polar code
oil: discharge into the sea from the ship is prohibited
heavy fuel is banned, ships are encouraged not to use or carry fuel oil
sewage: no discharge into the sea from the ships
changes to the carbon/water cycle
water
Diurnal changes: night: lower temperatures which reduce evaporation and transpiration. Day: direct heating = precipitation often raining in the afternoon
seasonal changes: Around December time low evaporation rates. Around June there is high evaporation rates = exhaustion of soil moisture and river flows
long term changes: lower rates of evapotranspiration reduce exchange of water between atmosphere + oceans + biosphere + soil. Glacial net transfer of water from ocean reservoir to storage in ice sheets, glaciers + permafrost. Sea level word wide falls as ice sheets + glaciers expand to cover 1/3 of the continental land mass
carbon
Diurnal changes: day: CO2 flows from the atmosphere to vegetation. Night: without sunlight, photosynthesis switched off and vegetation loses CO2 to the atmosphere
Seasonal changes: summer: high photosynthesis when trees are in full foilage, there is a net global flow of CO2 from atmosphere to biosphere. Rising water temperature, more intense sunlight and the lengthening of photoperiod stimulate phytoplankton in the oceans. Autumn: as photosynthesis ends the flow is reversed with decomposition releasing CO2
Long term changes: dramatic reduction of CO2 in the atmosphere (correlates with temperature) vegetation stores shrink as ice sheets advance carbon stores in soils which are no longer exchanged to the atmosphere. Expanses of tundra sequester huge amounts of carbon in permafrost. NPP declines.
global management strategies to protect the carbon cycle
wetland restoration: includes salt marshes
Positives: carbon sink, improves biodiversity
example: management initiatives such as international convention on wetlands
pressured from population growth, economic development + urbanisation
Afforestation: planting trees in deforested areas or areas that have never been forested
positives: carbon sink, reducing flood risks + soil erosion, increasing biodiversity
example: the Un reducing emissions from deforestation and forest degradation scheme incentives developing countries to conserve their rainforests
cap + trade: international market based approach to limit CO2 emissions
if businesses emit less then they receive carbon credits which can be traded on international markets
carbon offsets are credits awarded to countries +companies for schemes such as afforestation and renewable energy
agricultural practices
reducing ploughing of the land: conserve the soils organic content reduces erosion
polyculture: growing crops interspersed with trees which provide ground coverage to protect soils
crop residues: leaving crop residues of the fields after harvesting
manure management: controlling the way methane decomposes- storing it in anaerobic containers + capturing CH4 as a source of renewable energy
Human activities
causing change in the carbon cycle
fossil fuels 87% of primary energy consumption
rapid industrialisation of the Chinese + Indian economies is speeding carbon usage further
soil store has been degraded by erosion caused by deforestation + agricultural mismanagement
causing change in the water cycle
rising demand (public supply + agriculture
quality of fresh water sources has been declined
deforestation, urbanisation, impermeable surfaces, rate of evapotranspiration reduced, increase surface run off
we are having a negative impact on the water and carbon cycle through land use changes as it has increased river flows and flood risks though urbanisation. Similarly carbon stores are reducing due to clearance for farming
Carbon and water in the atmosphere
water