Carbon and Water cycles Flashcards
what are systems?
systems are a set of things working together as part of a mechanism or an interconnecting network: a complex whole
what are systems composed of?
- inputs
- outputs
- stores
- flows
- boundaries
what is an input in a system?
where matter or energy is added to the system
what is an output of a system?
where matter or energy leaves the system
what are stores of a system?
where matter or energy builds up in the system
what are flows of a system?
where matter or energy moves in the system
what are boundaries of a system?
limits to the system (e.g. watershed)
what are open systems?
a system that freely exchanges energy and matter with its surroundings
what are closed systems?
a system that exchanges only energy with its surroundings, NOT MATTER
what is an isolated system?
a system that does NOT exchange energy or matter with its surroundings
what is a dynamic equilibrium?
a state of balance within a system
when inputs equal outputs despite changing conditions.
what is positive feedback?
occurs when a chain of events amplifies the impacts of the original event.
what is negative feeback?
refers to a chain of events that nullifies the impacts of the original event, leading to dynamic equilibrium.
what type of systems are the carbon and water cycles on a local scale?
both open systems
what types of systems are the carbon and water cycles on a global scale?
both closed systems
what is a example of a local scale water cycle system?
local drainage basin
what type of water system is a local drainage basin?
an open system
water may be lost as an output through evapotranspiration and runoff, but more water may be gained as an input through precipitation.
what is the input of a local drainage basin system?
precipitation
what are the outputs of a local drainage basin?
evapotranspiration - the combined return of water to the atmosphere from evaporation and transpiration (plants)
streamflow - water that flows through streams and into the ocean or as tributes to other rivers
what are the stores of a local drainage basin?
-ground water - water stored in pore spaces of rocks
-soil waters
-rivers
-interception - water stored temporarily by by trees etc, before it reaches the ground
-surface
what are the flows of a local drainage basin?
-infiltration - water moving from above ground into the soil
-peculation - water moves from the ground or soil into porous rocks or rock fractures
-throughflow - flow of water through soil
-surface runoff
-groundwater flow - flow of water through the rocks
-stemflow - low of water that has been intercepted by plants or trees, down a stem, leaf, branch or other part of a plant
what are the earths 4 subsystems?
atmosphere
lithosphere
hydrosphere
biosphere
what does changing phase mean?
when a substance changes from one state to another
what are the earths 4 major stores of water
- atmospheric water
- cryospheric water
- oceanic water
- terrestrial water
what is atmospheric water?
water found in the atmosphere; mainly water vapour with some liquid water (cloud and rain droplets) and ice crystals
what is cryospheric water?
the water locked on the earths surface as ice
what is oceanic water?
the water contained in the earths oceans and seas but not including the inland seas such as the Caspian sea
what is terrestrial water?
this consists of groundwater, soil moisture, lakes, wetlands and rivers
what is the water balance?
the water balance is used to express the process of water storage and transfer in a drainage basin system
what is the formula the water balance uses?
precipitation = total runoff + evapotranspiration +/- storage
why is it important to use the water balance in your answers?
it could be applied to explain droughts or floods
what is the water cycle on a local scale impacted by?
-deforestation - less interception, soil less able to store water
-storm events - increases runoff and water storage
-seasonal changes - more interception in spring; snow reduces flow; hot weather reduced precipitation
-agriculture - pastoral (livestock) ground trampled to less infiltration; arable (crops) ploughing increases infiltration. ditches increase infiltration
-urbanisation - impermeable surfaces increase runoff
soil water budget
shows the annual balance between inputs and outputs in the water cycle. the soil water budget also shows how inputs and outputs impact soil water storage and availability
describe the water cycle in winter months?
there is a surplus of water I the winter months, after recharge of soil water in autumn. soil water is recharged in autumn because of the inputs of precipitation exceed the outputs of evapotranspiration (because it rains more and is cooler)
describe the water cycle in the summer months?
the water is utilised in spring and summer, when potential evapotranspiration of plants is higher because of the warmer weather
field capacity
maximum storage of water in the soil
what is the water budget dependant on?
-type
-depth
-permeability of soil and bedrock
what is the hydrosphere?
any liquid water
what is the lithosphere?
water stored in the crust or upper mantle
what is the cryosphere?
any water that is frozen
what is the atmosphere?
water vapour
aquifer
underground water stores and on a global scale they can be unevenly distributed
shallow groundwater aquifers
can store water for up to 200 years
deeper fossil aquifers
formed during wetter climactic periods, may last for 10,000 years
glaciers
from accumulation to ablation/calving, they may store water for 20-100 years, which may feed lakes that store water or 50-100 years
seasonal snow cover and rivers
both store water for 2-6 months
soil water
acts as a more temporary store, holding water for 1-2 months
how does the water cycle change through natural processes?
- less precipitation, more evaporation in summer because of higher temperatures
- reduced flows in winter as water is stored as ice
- reduced interception in winter, when deciduous trees lose their leaves
- increased evapotranspiration in summer; deciduous trees have their leaves/higher temperatures
how does the water cycles change through human impacts?
farming practices:
- ploughing breaks up the surface, increasing infiltration
- arable farming (crops) can increase interception and evapotranspiration
- pastoral farming (animal) compacts soil, reducing infiltration and increasing runoff
land use change:
- deforestation (e.g. for farming) reduces interception, evapotranspiration but infiltration increases (dead plant material in forests usually prevents infiltration)
- constructions reduces infiltration and evapotranspiration, but increases runoff
water abstraction (water removed from stores for human use):
- this reduces the volume of water in surface stores (e.g. lakes)
- water abstraction increases in dry seasons (e.g. water is needed for irrigation)
- human abstraction from aquifers as an output to meet water demands is often greater than inputs to the aquifer, leading to a decline in global long term water stores
floor hydrograph
used to represent rainfall for the drainage basin of a river and the discharge of the same river on a graph
what factors effect whether a flood hydrograph is flashy?
- short lag time
- steep rising and falling limb
- higher flood risk
- higher peak discharge
what factors effect whether a flood hydrograph is subdued?
- long lag time
- gradual rising and falling limb
- lower flood risk
- lower peak discharge
where does the carbon cycle occur on a local scale?
in a plant, or sphere such as the lithosphere, which is vegetation succession that occurs on bare rock. over time a soil builds up on the rock from decaying organic matter. the climactic climax (final stage of a vegetation succession) is achieved when the ecosystem can develop no further e.g. when a woodland is formed
photosynthesis
- carbon transfer
living organisms convert carbon dioxide from the atmosphere and water from the soil, into oxygen and glucose using light energy. this removes CO2 from the atmosphere
respiration
- carbon transfer
the opposite of photosynthesis.
when living things (plants, animals, microorganisms) break down food and release carbon dioxide.
combustion
- carbon transfer
burning fossil fuels
wildfires
releases CO2 into the atmosphere
decomposition
- carbon transfer
when living organisms die, they are broken down by decomposers which respire, returning CO2 into the atmosphere. some carbon is also returned to the soil
diffusion
- carbon transfer
the oceans absorb CO2 from the atmosphere, but this harms aquatic lie by causing coral bleaching
weathering and erosion
- carbon transfer
rock particles broken down and transferred to the ocean, where carbon us used by marine organisms to create shells
burial and compaction
- carbon transfer
sea shell fragments become compacted over time to form limestone and organic matter may form fossil fuels
carbon sequestration
- carbon transfer
transfer of carbon from the atmosphere and can be both natural and artificial. Carbon sequestration is the process of capturing and storing atmospheric carbon dioxide.
marine sediments and sedimentary rocks
- main carbon store
lithosphere - long term
oceans
- main carbon stores
hydrosphere - dynamic
fossil fuels deposits
- main carbon stores
lithosphere - long term but currently dynamic
soil organic matter
- main carbon stores
lithosphere - midterm
atmosphere
- main carbon stores
dynamic
terrestrial plants
- main carbon stores
biosphere - midterm but very dynamic
what is the lithosphere?
the lithosphere is the main store of carbon, with global stores unevenly distributed. for example, the oceans are larger in the southern hemisphere, and storage in the biosphere mostly occurs on land. terrestrial plant storage is focussed in the tropics and the northern hemisphere.
how does the carbon cycle change through natural processes?
- wildfires - transfer carbon from biosphere to atmosphere as CO2 is released through burning. can encourage the growth of plants in the long term
- volcanic activity - carbon stored within the earth is released during volcanic eruptions, mainly as CO2 gas
how does the carbon cycle change through human impacts?
- fossil fuel use - combustion transfers CO2 to the atmosphere from a long-term carbon sink
- deforestation - often used to clear land for farming/housing, rapidly releases carbon stored in plants using slash and bur techniques and interrupting the forest carbon cycle
- farming practices - arable farming releases CO2 as animals respire. ploughing can release CO2 stored in the soil. farm machinery such as tractors may release CO2.
carbon budget
the balance between carbon inputs and outputs to a store at any scale e.g. the carbon budget in the atmosphere has inputs from respiration and combustion but outputs including the oceans/photosynthesis.
carbon source
a store that emits more carbon than it absorbs e.g. a damaged rainforest
carbon sink
a store that absorbs more carbon than it emits e.g. a virgin rainforest
the enhanced greenhouse effect
the process that is currently causing global warming as abnormally high levels of greenhouse gases are being produced by humans, trapping radiation from the sun, causing global warming and leading to climate change.
what are impacts of the carbon cycles on regional climates?
tropical rainforests:
- high rates of photosynthesis and respiration in forests lead to greater humidity, cloud cover and precipitation
- deforestation reduces photosynthesis and respiration, further reducing humidity and cloud cover and decreasing precipitation
oceans
- warmer oceans cause more plankton growth and through plankton chemical production, cause clouds to potential form
tropical rainforests - interrelationships between the cycles
- natural rainforest water cycle
- precipitation falls
- 75% intercepted by trees an through stem flow 35% reaches the ground and infiltrates the soil and another 35% is used by plants and through transpiration returns to the atmosphere
- 25% evaporates almost immediately and returns to the atmosphere
tropical rainforests - interrelationships between the cycles
- deforested rainforest water cycle
- precipitation falls
- most reaches the ground immediately with little vegetation to intercept the rainfall leading to high surface runoff, with higher flooding risk
- less evapotranspiration, so the atmosphere is less humid and rainfall decreases
tropical rainforests - interrelationships between the cycles
- natural rainforest carbon cycle
- trees suited to humid and warm conditions, which promotes photosynthesis
- they absorb large amounts of oxygen from the atmosphere acting as an important carbon sink
- decomposition and respiration releases CO2 back to the atmosphere and soil, where carbon is stored
tropical rainforests - interrelationships between the cycles
- deforested rainforest carbon cycle
- lack of trees so photosynthesis is reduced
- fires to clear land leads to CO2 beige released into the atmosphere. forests become a carbon source instead of a carbon sink
- lack of life until new plants grow
- low rates of decomposition occurs in this environment
relationships between the water cycle and the carbon cycle
- rain that forms over intact tropical rainforest may fall over deforested land due to wind, causing erosion, with soil and ash flowing into rivers, increasing the carbon content o rivers. the water leaves the rainforest cycle as an output through streamflow due to reduced interception and increases surface runoff
- alternatively there is reduced rainfall in the intact forest, as there is less evapotranspiration in the deforested area, causing drought periods and the intact rainforest to deteriorate
- deforestation on peatlands and the digging of drainage channels reduce water storage. the organic peat matter is no longer preserved underwater and decomposes quickly, releasing CO2 into the atmosphere. weathering and erosion increase speeding up decomposition. there is greater wildfire risk from the hotter temperatures
- blocking drainage ditches in peatland rainforests, help restore the natural environment by increasing soil water storage and decreasing runoff. this can raise the water table and decrease the flood risk. however, a managed forest is often less effective at sequestering CO2 than a virgin forest
mitigating climate change - global intervention
Paris Climate Deal (COP21)
- aim to limit global temperatures to 2*C above pre-industrial levels
- support for developing countries
- public interaction and awareness schemes
- meet every 5 years to review and improve goals
mitigating climate change - regional intervention
EU 20-20-20
- 20% reduction in GHG emissions and commitment to 20% of energy coming from renewable sources and 20% increase in energy efficiency by 2020
- EU has suggested it will increase its emissions reduction to 30% if major GHG producing countries also improve their targets
mitigating climate change - national intervention
Climate Change Act 2008 UK
- legally binding target for the UK to reduce GHG emissions by 80% of 1990 levels by 2050 with a target of 26% by 2020 which has recently increased to 34%
- created national carbon budgets and the independent committee on climate change to help the government and report on progress that is being made
mitigating climate change - local scale
- improving home insulation
- recycling
- using energy more wisely and using smart meters
- using public transport or car sharing schemes
- calculating personal carbon footprints
