ELSS Flashcards
Describe what the Goldilocks’ Zone is
The Earth is the perfect distance from the sun to support life.
It is the habitable zone which is not too hot or too cold to have liquid water.
Explain why water is so important to life on Earth
It is required for photosynthesis.
Plant tissues need water, or they will wilt.
Fauna need water to regulate internal temperatures.
Water plays a big role in economic activities.
Define: hydrosphere, cryosphere, lithosphere, biosphere, atmosphere
Hydrosphere: the total water storage on a planet, including oceans, lakes, rivers.
Cryosphere: the frozen part of the earth system, such as glaciers.
Lithosphere: the solid, outermost layers of the earth’s structure, the crust and mantle.
Biosphere: the parts of earth where life exists.
Atmosphere: the layers of gases surrounding earth which shield against UV rays and insulate the earth.
Give an example of an input, output, process and store in the water cycle
Input – precipitation
Output – evaporation and transpiration
Process - evaporation, convection, condensation, precipitation and collection
Store – ocean, ice caps, land and atmosphere
Give an example of an open and a closed system and describe the difference between them
The earth’s water and carbon cycles are a closed system, no water leaves or enters the atmosphere. Only the sun’s energy (and not matter) cross the boundaries.
A drainage basin is an open system. Materials such as sediment and water leave and enter the system as well as the sun’s energy.
What is dynamic equilibrium? Describe the difference between positive and negative feedback using examples
Dynamic equilibrium is when a system’s inputs and outputs are equal. Dynamic means there are constant inputs, outputs, throughputs and variable stores of energy and materials.
Positive feedback is when an initial change causes further change, like a snowball effect. Global warming – warmer, more water vapor, green-house gas.
Negative feedback counters the system change and restores equilibrium. Global warming – increased cloud cover, reduces solar radiation to earth.
water stores and their challenges
Oceans – 97% Polar ice and glaciers – 2% Groundwater – 0.7% Atmosphere – 0.001% Biosphere – 0.00004%
The average residence time of a water molecule in the atmosphere is 9 days.
Accessible surface water is 1% of all freshwater, it is scarce.
Cryosphere – once these stores melt it is likely they will not freeze until the next glacial period.
Describe the distribution of the different stores of fresh water
68% is stored as ice caps and glaciers.
30% is stored as groundwater
Characteristics of inputs and outputs of WC
Inputs to atmosphere: water vapour from oceans, soils, lakes and rivers, and transpired water from leaves.
Leaves atmosphere as precipitation and condensation.
Ice and snow release water by ablation.
Precipitation and meltwater reaches rivers by run-off and infiltration of soil.
Water percolates into permeable rock or aquifers.
Groundwater reaches surface again as springs.
Characteristics of inputs and outputs of CC
Chemical weathering happens due to acid rain (precipitation with CO2). This releases carbon to atmosphere.
Partly decomposed organic material is buried under younger sediment to form carbonaceous rocks – coal, oil, natural gas (carbon sink for millions of years)
Phytoplankton uses CO2 for photosynthesis and water to make carbohydrates - foundation of food chain.
Respiration and decomposition release CO2 to atmosphere.
Precipitation
water and ice that falls from clouds; rain, snow, hail, sleet and drizzle. Once vapour forms clouds after reaching dew point, particles aggregate, reach critical size and leave as precipitation.
High intensity moves rapidly overland into streams and rivers. Precipitation may be concentrated in rainy seasons causing river discharge to be high and floods occur.
Transpiration
the diffusion of water vapour to the atmosphere from stomata. It is influenced by temperature, wind speed, water availability to plants. Deciduous trees shed their leaves in dry or cold seasons to reduce moisture loss.
Condensation and types of clouds formation
Condensation: clouds form through vapor turning to liquid when it reaches its dew point.
Cumuliform clouds - flat bases, considerable vertical development. Develop when air is locally heated through contact with earth’s surface.
Stratiform clouds - layer clouds formed when air mass moves horizontally across a cooler surface (advection).
Cirrus clouds - form at high altitude and have tiny ice crystals. Do not precipitate.
Condensation near ground produces dew or fog. These all deposit moisture on vegetation and surfaces.
Convection/lapse rates
Cloud formation/lapse rates: cooling occurs when a warm air mass mixes with a cooler one.
Air warmed by contact with earth rises through atmosphere, causing adiabatic expansion, the movement is convection.
Advection.
Air masses rise as they cross mountain barrier or turbulence forces them to rise.
Lapse rates describe the vertical distribution of temp in lower atmosphere and the temp changes that occur within an air parcel as it rises from ground.
Describe how wind speed, vegetation type, tree species & interception storage capacity affect interception loss
Wind speed: rates of evaporation increase with wind speed. Turbulence also increases with wind speed causing additional throughfall.
Vegetation type: interception loss is greater from grasses than crops. Trees, which have a large surface area and aerodynamic roughness, have higher interception loss than grass.
Tree species: loss is greater from evergreen conifers than from broad-leaved deciduous trees. Most conifers have leaves all year round and water adheres to spaces between needles, increasing evaporation.
Storage capacity: before rainfall, vegetation surface is dry and at maximum ability to retain water. Most rainfall is intercepted, but as vegetation becomes saturated, throughfall increases. Interception depends on duration and intensity of rainfall.
Describe what happens to temp and pressure as air moves upwards and what the environmental lapse rates are
Temperature decreases and pressure falls, causing air to cool and expand, therefore condensating.
The ELR is the vertical temp profile of lower atmosphere at any given time.
Temperature tends to fall by 6.5C for every km of height gained.
Explain what adiabatic expansion is and what the difference is between DALR and SALR.
Adiabatic expansion is when the warm air rises and as pressure falls it cools by expansion.
The DALR is the rate at which the temperature of dry air cools and is caused by adiabatic expansion (10C/km).
The SALR is the rate at which the temperature of a parcel of air saturated with water, cools as it rises through atmosphere. Condensation releases latent heat so SALR (7C/km) is lower than DALR.
Precipitation CC
rising concentrations of CO2 in atmosphere have increased the acidity of rainfall. This has increased acidity of ocean surface waters, affecting marine life.
Photosynthesis CC
using the Sun’s energy, CO2 and water, plants and phytoplankton convert light energy to chemical energy. They use this glucose to maintain growth, reproduction, and life processes.
Weathering CC
rainwater is a weak carbonic acid which dissolves limestone and chalk (carbonation). This releases carbon to water stores and atmosphere. Rainwater mixed with decaying organic material (TRF leaf litter) forms humid acids which attack rock minerals.
Respiration CC
absorbs oxygen and releases CO2. Glucose is converted to CO2 and water.
Decomposition CC
bacteria breaks down dead organic matter, extracting energy and releasing CO2. Faster in warm, humid climates.
Combustion CC
organic matter burns in the presence of oxygen. This releases CO2. Long winters slow decomposition of forest litter and fire shifts this jam, freeing carbon and nutrients for trees. Also opens forest canopy, allowing for new habitats and biodiversity.
Why is carbon important to life
Carbon can bond with other atoms, this gives flexibility to the form and function of biomolecules, such as DNA, these are needed for life, growth and replication.
Used in photosynthesis.
slow and fast carbon cycle
The ocean needs to be cold to absorb CO2.
Slow cycle: time span of 10 million to 100 million years.
Fast cycle: time span of 350 years.
physical pumps
Physical pumps (downwelling): absorbing of CO2 by ocean water, carbon is moved downwards by currents, as it sinks it becomes cooler and denser.
Physical pumps (upwelling): carbon can be stored for centuries at low depths, it then moves to an area where ocean currents move it upwards to surface, it diffuses back into atmosphere.
biological pumps
Biological pumps: phytoplankton float near surface and absorb sunlight, water and dissolve CO2, this becomes locked in phytoplankton and accumulates on sea floor, is decomposed and released as CO2.
Describe the distribution of TRF and the annual climate in the Amazon and the Arctic tundra
The tropical rainforest is found on the equator, in Africa, the Neotropics and Indo-Pacific region.
Amazon: tropical environment, hot and humid. Rain falls year-round.
Arctic Tundra: average temperature is –12C to –6C. Cold and windy, rainfall is not regular.
Water cycle in TRF
Precipitation: high annual convectional rainfall (>2000mm). There may be a short dry season.
Evapotranspiration: high rates due to high temperatures, abundant moisture and dense vegetation. Strong feedback loop - half of incoming rainfall is returned to atmosphere.
Run-off: rapid run-off is related to high and intense rainfall, and well-drained soils. River discharge may peak in months of the year where there is more rainfall.
Atmosphere: high temperatures allow the atmosphere to store large amounts of water (absolute humidity is high).
Soil/groundwater: a lot of rainfall and deep soils lead to significant water storage in soils and aquifers.
Vegetation: trees absorb and store water from the soil and release it through transpiration.
Carbon cycle in TRF
NPP is 2500 grams/m2/year and biomass is between 400 and 700 tonnes/ha.
Large forest trees store 180 tonnes C/ha above ground and 40 in their roots.
Soil stores between 90 and 200 tonnes C/ha.
The Amazon absorbs 2.4 billion tonnes of carbon each year.
Exchange of carbon between atmosphere, biosphere and soil are rapid. Dead organic matter decomposes quickly due to warm and humid conditions and CO2 is released quickly.
Leached and acidic soils only contain a small amount of nutrients and so decomposition of matter and recycling of minerals is important.
Water Cycle in the Arctic Tundra
Low precipitation (50-350mm) and most is snow.
Limited transpiration because of sparse vegetation and a short growing season.
Low rates of evaporation - surface and soil water and frozen for most of the year.
Limited groundwater and soil stores. Permafrost acts as a barrier to infiltration, percolation, recharge and groundwater flow.
Snow and lake ice accumulates in winter. During summer, the snow and ice melts, and the active layer of permafrost, increasing river flow.
Extensive wetlands, ponds and lakes during summer.
Seasonal changes to tundra water cycle
Most of the year water is stored as ground ice in permafrost but in short summer active layer thaws.
Millions of pools and lakes form in summer.
Drainage is poor due to permafrost depth, but some evapotranspiration occurs from standing water, saturated soil and vegetation.
Humidity low all year and precipitation is sparse.
Carbon cycle in the Arctic Tundra
The permafrost contains 1600 GT of carbon. The accumulation of carbon is due to low temperatures and slow decomposition.
Carbon accumulates due to low temp and slow decomposition.
During the growing season, carbon fluxes, tundra plants input carbon-rich litter to the soil. Activity of micro-organisms increases, releasing CO2 through respiration.
Permafrost was a carbon sink, but it is becoming a carbon source as it melts.
Although, higher temps have caused plant growth, which absorbs carbon, so carbon budget remains in balance.
Low temp and waterlogging slow decomposition and respiration and flow of CO2 to the atmosphere.
Seasonal changes to tundra carbon cycle
Carbon mainly stored as frozen partly decomposed plant remains in permafrost (for 500000 years).
For most of the year there is little plant growth due to low temp, lack of water, and few nutrients.
In the 3-month growing season, the long hours of daylight help to increase photosynthesis and NPP.
Explain how these factors affect the Arctic tundra:
Temperature
Permeability
Geology- porosity, relief and mineral composition
Vegetation
Soil organic matter
Soil organic matter: carbon is mainly stored as partly decomposed plant remains frozen in permafrost. This has been locked away for 500000 years.
Vegetation: growing season lasts about 3 months; low temp, lack of water and few nutrients limit the growth.
Temperature: temperature is usually below freezing so water is stored in permafrost ice. During warmer months liquid water flows on surface. Water cannot infiltrate soil.
Permeability/geology: low due to permafrost. Crystalline rocks also cause low permeability. Underlying rock in tundra is now a gently undulating plane due to erosion and weathering.
Minimal relief impedes drainage and contributes to waterlogging in summer months.
Describe the main changes/threats to the water cycle in the Amazon
Deforestation in Amazon between 1970 and 2013 was 17500km2/year.
Madeira River flood (2014), river was 19.68m above normal.
Deforestation has reduced water storage in trees, soils (which have been eroded), permeable rocks (more rapid run-off) and the atmosphere. Increased run-off speeds increase the risk of floods.
Fewer trees mean less evapotranspiration and precipitation.
2012, 30000km2 of Bolivian rainforest was cut down for farming and cattle ranching, reducing water storage and accelerating run-off.
Converting forest to grassland increases run-off by 27 and this goes straight to rivers.
Deforestation breaks the cycle which forms cloud and convectional rainfall, this can lead to permanent climate change.
Future deforestation could cause a 20% decline in regional rainfall as the forest dries out.
Describe the main changes/threats to the carbon cycle in the Amazon
Biomass of trees represents 60% of carbon in whole ecosystem. Deforestation exhausts this carbon store.
Grasslands only store about 16 tonnes/ha.
Deforestation reduces inputs of organic material to soils, and as they are exposed to strong sunlight, they support fewer decomposers and so the flow of carbon is reduced.
The principal store of plant nutrients is forest trees, the soils only contain a small amount of nutrients. The forest is sustained by the rapid nutrient cycle.
Deforestation destroys the main store and removes nutrients (calcium, potassium, magnesium) from ecosystem.
As the nutrients are no longer absorbed by roots, they are washed away by rainwater.
Soils are eroded by run-off as there is no protective cover of trees.
ARPA
Covers an area 20 times the size of Belgium.
By 2015, 44% of the Brazilian Amazon comprised national parks, wildlife reserves and indigenous reserves where farming is banned.
Parica project
Aims to develop a 1000km2 commercial timber plantation on gov owned, deforested land.
They want 20 million fast growing, tropical, hardwood seedlings, planted on 4000 smallholdings, to mature over 25 years.
Financial support is provided for smallholders for land preparation, planting and maintenance.
Monoculture due to planting same trees.
Reduces CO2 in atmosphere, restores carbon and water cycles, reduces run-off and nutrient loss from soil.
REDD
Pays Survi tribe to protect the rainforest and abandon logging. Costs a lot and requires cooperation.
Market based approach which provides carbon credits to the Survi. These can be purchased by international companies which have exceeded their annual carbon quota. In 2013, Natura purchased 120000 tonnes of carbon credits.
diversification of farming
Soil fertility can be maintained by rotational cropping and combining livestock and arable operations.
Integrating crops and livestock could allow a fivefold increase in productivity and slow deforestation.
Dark soil production (charcoal, waste and human manure) will allow permanent cultivation.
Describe the tundra soils and explain what permafrost is
Tundra soils lack nutrients for vegetation. Soils are covered by a layer of permafrost. This is permanently frozen ground. Only the top metre thaws in arctic summer.
Explain how oil/gas drilling has affected the water and carbon cycles in the tundra.
Most oil is drilled from the Alberta Oil Sands, which is the world’s third largest oil reserve at 170 billion barrels.
WC issues: for every barrel shipped out, 6-12 barrels of tailings waste is produced. Tailing ponds have been growing for over 50 years and are leaking into Athabasca River. Air pollution and acid rain could damage an area the size of Germany.
CC issues: producing tar sands oil results in 14% more greenhouse gas emissions than the average oil used in the US. Emissions per barrel have begun to slightly increase. Melting permafrost releases 7-40 million tonnes of CO2 per year. Destruction of vegetation reduces photosynthesis and absorption of CO2.
4300 production wells
russian tundra - flaring - gas extractors burn off excess condensate
Evaluate the success of:
Insulated ice and gravel pads, elevating buildings and pipelines, drilling laterally, refrigerated supports
Pipelines on stilts: reduces heat transfer so there will be a reduction in permafrost melting. Less liquid water. Heat can still be transferred, stilts can break.
810ft pipeline bending due to permafrost melt and shift
100 thermosyphons remove heat from permafrost
Drilling laterally from rigs: more oil can be drilled without lots of wells so less CO2 is released from gas flaring. Could be difficult to implement.
orion oil pool has 5 wells and 15 lateral well branches
Refrigerated supports on pipeline: reduces heat transfer through the stilts. There will be less melting of permafrost. Equipment could fail due to extreme temperatures.
-6 to -12
Arctic Council 2009 report: sets out recommended ways of doing things. Guidelines help to advise and reduce environmental damage. It is not legally binding so can be ignored.
loss of 1000s jobs
US gov ban sale of drilling rights: legal deterrent and preserves land. Government could lose money.
Describe how urbanisation, forestry, farming, have a +/- change on the WC/ CC.
Urbanisation: artificial surfaces are impermeable so allow little infiltration and provide minimal water storage capacity to buffer run-off. Drainage systems remove water rapidly so high proportion of water from precipitation flows quickly to stores and causes rapid water rise.
Farming: crop irrigation diverts surface water from rivers and groundwater to cultivated land. This water is extracted by crops from soil and is released by transpiration so most water is lost.
Forestry: felling to harvest timber causes increase in surface run-off and floods. Trees are reforested to ensure not too much carbon is released into atmosphere.
Describe how water extraction and aquifers/ artisan wells have a +/- change on the WC/ CC.
Water extraction: falling water table has reduced flows in River Kennet by 10%. Lower flows have reduced flooding and wetlands on the floodplain. Lower groundwater levels have caused springs to dry up.
Aquifers: over exploitation in 19th and 20th century caused drastic fall in water table. Water demand declined in past 50 years so water table rose 3m/year. Since 1992, Thames water grants abstraction licenses to slow rise of water table which is now stable.
Describe what carbon sequestration is and explain whether it is a viable strategy at this time
The process of capturing and storing atmospheric carbon.
It is done to reduce the amount of carbon dioxide in the atmosphere, with a goal of reducing global climate change.
May not be viable as it is very expensive and can only be done on land with a layer of impermeable rock covering porous, permeable rock. This specific kind of land is hard to come by.
Impact of fossil fuel combustion and carbon sequestration
¾ of CO2 emissions are from burning fossil fuels. CO2 levels are the highest they have been in 800000 years.
Without increased absorption of anthropogenic carbon by oceans and biosphere, atmospheric carbon would exceed 500ppm.
To reduce the effects, it’s having on global warming, carbon capture and storage could be used.
In USA, CCS has capability of reducing carbon emissions by 80%.
Drax project got cancelled due to high cost – would be £1 billion.
20% of power plants energy is needed.
Requires specific geology – porous covered by impermeable.
Describe how the WC and CC change diurnally and seasonally
Diurnal changes: within 24 hours. Lower temp at night reduces evapotranspiration. Convectional precipitation is a daytime phenomenon and falls in afternoon when temp reaches a max. Significant in tropical regions where most precipitation comes from convectional storms.
During the day CO2 flows from atmosphere to vegetation, this reverses at night. Without sun, photosynthesis stops, and vegetation loses CO2 to atmosphere.
Seasonal changes: seasons are controlled by the intensity of solar radiation, which peaks mid-June and is low in December. Evapotranspiration is highest in summer and lower in winter. In England, large losses of precipitation in summer cause river flows to be at their lowest.
Carbon cycle is shown by monthly variations in NPP. In middle/high latitude, day length and temperature drive changes. In the tropics it is mainly influenced by water availability.
Explain the effects of long-term climate change the water cycle and what might happen in the future
WC: increased temp = increased evaporation. Water vapour is a GHG so has a feedback effect, raising temp and causing more evaporation.
Increased precipitation also means more run-off and flood risks.
Vapour is a source of energy in atmosphere and increased energy can lead to hurricanes and storms becoming more intense and frequent.
Higher temp melts glaciers and arctic permafrost. Cryosphere storage is decreased and is transferred to oceans and atmosphere.
Explain the effects of long-term climate change on the carbon cycle and what might happen in the future
Higher temperatures will increase rates of decomposition and the transfer of carbon from biosphere to atmosphere. In high altitudes, global warming will allow boreal forests in Canada to expand poleward.
Acidification of oceans due to absorbing excess CO2 reduces photosynthesis via phytoplankton limiting ability to store carbon in ocean. So, increase in carbon stored in atmosphere and reduction of biosphere and ocean stores.
Evaluate the success of wetland restoration, afforestation, agricultural practices
Wetland restoration (CC): waterlogged conditions are recreated to increase water table, which more carbon can be stored in. This means less water is stored in atmosphere. store more carbon than veg. globally. damaged wetlands responsible for 5% CO2 emissions.
Afforestation (CC): the replanting of trees in deforested areas is cheap and viable in all countries. Increase of trees increases carbon storage and reduces flood risks.
Agricultural practices (CC): land, crop and livestock management can be expensive as products such as anaerobic containers are needed. Farmers must also be in agreement. 67% farmers said its important. 18% said too expensive.
Evaluate the success of International agreements to limit carbon emissions
Cap and trade
Cap and trade: businesses are allocated an annual quota for CO2 emissions, and they can receive credits or financial penalties. Businesses must all agree and requires a lot of funding to sustain quota.
EU capped emissions 29% lower in 2018.
International agreement: Paris agreement to keep global warming below 2C. HICs will fund LICs but this can become expensive for HICs.
Evaluate the success of forestry, water allocations, drainage basin planning
Forestry: UNs REDD programme fund over 50 countries to protect and restore forests. Long term strategy which will stabilise regional water cycle. Offsets 430 million tonnes of carbon per year.
Water allocations: mulching and drip irrigation reduce water loss to evaporation and terracing reduces run-off. Is feasible but hasn’t been used much outside of developed world. Expensive and could interfere with natural landscape.
Drainage basin planning: rapid run-off is controlled by reforestation in upland catchments. EUs water directive framework sets targets for water quality, abstraction rates and flood control. Could be expensive as it involves many strategies.
How human activity changes carbon availability
87% of primary energy is fossil fuels. The use of it has removed billions of tonnes of carbon from geological store.
Land use change (deforestation) transfers 1 billion tonnes of carbon to atmosphere annually.
Phytoplankton absorb more than half of CO2 from burning fossil fuels.
