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ELSS - Coggle Diagram

- - - - Water enters as Evaporation from the oceans and evapotranspiration from the land
      - Water leaves as precipitation
    - - Water enters as precipitation and run off/ ground water flow
      - Water leaves as evaporation
    - - Water enters as precipitation
      - Water leaves as evapotranspiration and run off/ ground water flow (water is released from glaciers as ablation (sublimation or melting)
    - - Precipitation= evapotranspiration + streamflow +/- storage
    - - Precipitation
        
        Water/ ice that falls from clouds
        
        Forms when water vapour in the atmosphere reaches its dew point (the temperature in which air becomes saturated) and condenses into tiny water droplets or ice particles to form clouds, they clump together and eventually become so heavy it falls as precipitation
      - Transpiration
        
        The diffusion of water vapour to the atmosphere from leaf pores (stomata) of plants, it is responsible for around 10% of moisture in the atmosphere
        
        Influenced by temperature, wind speeds, water availability to plants, deciduous/ coniferous trees (deciduous plants purposefully shed their leaves in climates with dry or cold seasons to reduce moisture loss through transpiration)
      - Condensation
        
        Change of water state from vapour to a liquid
        
        Happens at the dew point and leads to cloud formation
      - Evaporation
        
        Liquid water to water vapour
        
        Heat energy hits the water and is absorbed as latent heat causing evaporation (rather than heating up the water)
      - Ablation
        
        The loss of ice from ice sheets, glaciers etc due to a combination of melting, evaporation and sublimation (it is a cyrospheric process)
      - Interception
        
        Vegetation intercepts precipitation and stores it temporarily on leaves, branches stems etc - Interception rates decrease as the duration and intensity of rainfall increase (as vegetation becomes more saturated)
        
        Interception loss - Eventually the moisture evaporates, falls to the ground known as throughfall (water that is briefly intercepted before reaching the ground) or flows down the trunk or stem (known as stemflow)
        
        Factors that affect the rate of interception loss:
        
        Wind speed
        
        Vegetation type (eg; greater from grasses have a lower interception loss rate than trees that have a larger surface area)
        
        Tree species (eg; evergreens have higher interception loss rates than deciduous plants as they have leaves all year round)
  - - - Co2 diffuses from the atmosphere into oceans where marine organisms such as clams and corals use this to produce calcium to form calcium carbonates (Caco3) used in their skeletons. When they die these sink the ocean floor, where they accumulate and eventually turn into sedimentary rocks (from heat and pressure)
      - Carbon held in rocks usually remains there for 150 million years, some are sub ducted into the upper mantle at tectonic plate boundaries and are vented to the atmosphere in volcanic eruptions
      - Surface rocks can be eroded by carbonation and co2 is released
    - - Carbon is passed between the atmosphere, living organisms and soils
      - These transfers are between ten and 1000 times faster than those in the slow carbon cycle
      - Land plants and microscopic phytoplankton in the oceans absorb co2 from the atmosphere through photosynthesis to form glucose (C6H12O6) which contains carbon, animals digest this and release co2 through respiration, decomposition also returns co2 back to the atmosphere
      - Atmospheric co2 also dissolves in ocean surface waters as well as oceans ventilating co2 back to the atmosphere (on average carbon atoms are stored in the ocean for an average of 350 years)
      - These processes of storing carbon are known as natural carbon sequestration
    - - Photosynthesis
        
        6CO2 + 6H20 > C6H1206 + 6O2
        
        Carbon dioxide + Water > Glucose + Oxygen
        
        Plants and phytoplankton use co2 from the atmosphere, water and light energy from the sun to convert it into glucose (chemical energy)
        
        The flux of carbon from the atmosphere to land plants and phytoplankton via photosynthesis averages around 120 gigatonnes a year
      - Respiration
        
        C6H1206 + 6O2 > 6CO2 + 6H20
        
        Glucose + Oxygen > Carbon dioxide + Water
        
        Plants and animals break down glucose, using oxygen, to create energy producing a bi-product of carbon dioxide and water
        
        Respiration and photosynthesis are the most important processes in the fast carbon cycle
      - Decomposition
        
        The process by which organic substances are broken down into simpler organic matter
        
        During the process co2 is released into the atmosphere
        
        Undertaken by bacteria and fungi
        
        Rates of decomposition depend on climatic conditions; the fastest rates occur in warm humid environments such as the tropical rainforest (slowest in cold dry environments eg; tundra or deserts)
      - Weathering
        
        The breakdown of rocks on or near the earth’s surface by chemical, physical and biological processes
        
        Chemical weathering from carbonation releases co2 from calcium carbonate in rocks eg; limestone
      - Carbonation
        
        CaCO3 + H2CO6 > Ca(HCO3)2
        
        Calcium carbonate + carbonic acid > calcium bicarbonate
        
        It is estimated that chemical weathering transfers 0.3 billion tonnes of Co2 every year
        
        The effectiveness of chemical weathering can be seen at Norber Brow in the Yorkshire Dales where the limestone surface has been lowered by nearly half a meter in the last 130,000 years
        
        Physical weathering processes (freeze thaw etc) and biological weathering (chelation) break rocks into smaller particles increasing their surface area and therefore the rate of carbonation
      - Precipitation
        
        Atmospheric co2 dissolves in rain water to form weak carbonic acid
        
        Rising concentrations of co2 in our atmosphere from anthropogenic emissions have led to rain and ocean acidification
        
        Oceans absorb around 1/3rd of co2 we emit, turning it into carbonic acid
        
        This has led to a decrease in ocean PH by 0.1 since pre-industrial levels (30% increase in acidity) Sea water is slightly basic therefore ocean acidification involves the shifting of the PH to become more basic rather than acidic
      - Combustion
        
        Occurs when organic material burns in the presence of oxygen
        
        Fuel + O2 → CO2 + H2O
        
        Also releases other gases such as nitrogen oxides and sulphur dioxides
        
        Wildfires caused by lightning strikes are essential to the health of some ecosystems such as the coniferous forests of the Rocky Mountains
        
        Long cold winters slow down decomposition leading to the build-up of forest litter on the floor, forest fires therefore remove this quickly, allowing trees to access carbon and nutrients that were previously inaccessible
        
        Combustion also takes place as a result of human activities eg; slash and burn techniques to clear land for grazing, however more importantly is the combustion of fossil fuels, current burning of fossil fuels releases 10GT of co2 a year into the atmosphere
    - - Carbon sequestration in the oceans
        
        Oceans ‘’take up’’ carbon by two mechanisms, through a physical (inorganic) and biological (organic) pump
      - Physical (inorganic) pump
        
        The movement of co2 from our atmosphere into the oceans through diffusion to form carbonic acid (H2CO3)
        
        Surface ocean currents then transport the water, when it reaches colder climates the water cools and sinks and the co2 can be transferred to the deep ocean where it can remain for many centuries, this is known as downwelling
        
        Downwelling only happens in a few places in the oceans eg; in the North Atlantic between Greenland and Iceland
        
        Eventually deep ocean currents transfer the water to areas of upwelling, where carbon rich waters rise to the surface and co2 diffuses back into the atmosphere
      - Biological (organic) pump
        
        The movement of co2 from our atmosphere into our oceans through phytoplankton (that live in the ocean’s surface layer) absorbing co2 via photosynthesis
        
        Phytoplankton are at the bottom of the marine food web, so when they are eaten carbon is transferred along the food chain
        
        Around 50 GT of carbon is drawn from the atmosphere by the biological pump every year
        
        The stored carbon can accumulate as sediment on the ocean floor however eventually the organisms decompose and co2 is released back into the atmosphere (however if dead organisms sink to the ocean floor the carbon can be transferred to the deep ocean)
        
        Marine organisms such as tiny coccolithophores, molluscs or crustaceans extract carbonate and calcium ions from sea water to manufacture shells and skeletons of calcium carbonate. Most of this carbon rich material ends up in ocean sediments and is ultimately lithified to form chalk and limestone
        
        Vegetation also stores carbon taken up by photosynthesis
- - - - Wetlands are areas that have a water table at or near the surface causing the ground to be permanently saturated, they include freshwater marshes, salt marshes, peatlands, floodplains etc
      - Wetlands are important in the carbon cycle as they occupy 6-9% of the earths land surface but contain 35% of the terrestrial carbon pool (acting as significant carbon sinks)
      - However, population growth and urbanisation have placed huge pressure on wetland environments eg; in the lower 48 US states the Wetland area has halved since 1600 and in the 20th century Canadas Prairie provinces lost 70% of their wetlands transferring large amounts of co2 and CH4 into the atmosphere
      - Therefore, restoring wetlands has become a priority, bodies such as the International Convention on Wetlands aim to promote restoration
      - Restoration involves raising local water tables to re-create waterlogged conditions eg; removing flood embankments, sea defences or maintaining artificially high water levels through drainage ditches
      - It has been estimated that restoration programmes in the area have shown that wetlands can store on average 3.25 additional tonnes of carbon per hectare per year
      - 112,000 hectares of wetlands have been chosen for restoration in the Canadian Prairies which should eventually sequester 364,000 tonnes of carbon annually
      - In the UK up to 400 ha of grade 1 farmland in East Cambridgeshire is currently being converted back to wetland in order to meet the UK governments target of restoring 500 ha by 2020
    - - Increases carbon stored in biomass that is then transferred to soils
      - The UNs ‘’Reducing Emissions from Deforestation and Forest Degradation’’ (REDD) scheme incentivises developing countries to conserve their rainforests by placing a monetary value on forest conservation
      - In China a massive government sponsored afforestation project began in 1978, it aims to afforest 400,000 km squared (an area roughly the size of Spain) by 2050, it involves planting non-native fast growing trees such as poplar and birch (the wider goal of the scheme is to combat desertification and land degradation in the vast semi-arid deserts of Northern China)
    - - Overcultivation and overgrazing can result in soil erosion releasing huge amounts of co2 into the atmosphere, intensive livestock farming produces 100 million tonnes a year of methane (CH4) additionally a huge amount of methane is also released from flooded (padi) rice fields and from uncontrolled decomposition of manure
      - Zero tillage practices have been introduced (growing crops without ploughing the soil to reduce oxidation and the removal of carbon)
      - Polyculture (growing crops interspersed with trees, gives extra carbon store as well as binding together soil to prevent it eroding)
      - Contour ploughing and terracing to reduce run off and erosion
      - Introducing new strains of rice that can grow in drier conditions and therefore produce less CH4 as well as applying chemicals such as ammonium sulphate which prevent microbial activities that produce CH4
      - Improving the quality of animal feed to reduce enteric fermentation so that less feed is converted into CH4
      - Storing manure in anaerobic containers to prevent methane entering the atmosphere as well as capturing CH4 as a source of renewable energy
    - - The Kyoto protocol - The 1997 Kyoto Protocol was the first major international agreement to tackle carbon emissions, it acknowledged climate change and that co2 emissions were a significant contributor to them and therefore aimed to reduce co2 emissions to ‘’a level that would prevent dangerous anthropogenic interference with the climate system’'
        
        It also acknowledged that different countries have different capabilities in combating climate change, due to their level of economic development, and therefore puts the obligation to reduce emissions on developed countries on the basis that they are historically responsible for the current levels of greenhouse gases in the atmosphere
        
        The Protocol's first commitment period started in 2008 and ended in 2012. All 36 countries that fully participated in the first commitment period complied with the Protocol. However, nine countries had to resort to the flexibility mechanisms by funding emission reductions in other countries because their national emissions were slightly greater than their targets. The financial crisis of 2007–08 is thought to have helped reduce the emissions. However even though the 36 developed countries reduced their emissions, the global emissions increased by 32% from 1990 to 2010, this is thought to be due to many developing countries being exempt from the agreement such as India and China (that were huge polluters)
        
        A second commitment period was agreed in 2012, known as the Doha Amendment to the Kyoto Protocol signed by 37 countries including the entire of the EU, however Canada withdrew from the agreement in 2012 and the US did not ratify it. Additionally, Japan, New Zealand and Russia did not enter the second term of agreements, leading way for the agreement to effectively end in 2012
      - The Paris Climate agreement - Signed in 2016 and as of 2019 195 UNFCCC members have signed it
        
        It has a long term temperature goal for average world temperatures to not increase more than 2 degrees above pre-industrial levels which should be done through peaking emissions as soon as possible
        
        Under the Paris Agreement, each country must determine, plan, and regularly report on the contribution that it undertakes to mitigate global warming however there is no mechanism to a country to set a specific emissions target by a specific date however each target set must go beyond previously set targets
        
        In June 2017 Trump announced the US would withdraw from the agreement and despite the agreement stating the earliest date of withdrawal for the US would be 2020, changes in US policy that are contrary to the Paris Agreement have already been put in place for example the U.S. Environmental Protection Agency (EPA) withdrew a requirement for oil and gas companies to report methane emissions
    - - Offers a market based approach to limit co2 emissions
  - - - The world relies on fossil fuels for 87% of its energy, this removes huge amounts of carbon from its geological store in coal, oil or natural gas and into the atmosphere. Currently around 8 billion tons of carbon a year are transferred to the atmosphere by burning fossil fuels
    - - Reduces the amount of carbon stored in the biomass, can also lead to soil leaching and the release of carbon into the atmosphere
    - - Phytoplankton absorb more than 50% of co2 from burning fossil fuels, significantly more than the tropical rainforest, ocean acidification threatens them
- - - - Occupies 8 million km2 in Northern Canada, Alaska and Siberia (located north of 66.5 degrees, within the Arctic circle)
      - Extreme conditions that become more severe with latitude, with temperatures as low as -40 degrees (for 8/9 months a year it has a negative heat balance with average monthly temperatures below freezing, meaning there is a near constant permafrost)
      - Low mean annual precipitation
      - Dark winters, light summers
      - Little biodiversity and apart from a few dwarf species the ecosystem is treeless (vegetation becomes more continuous with lower latitudes)
      - The Arctic Tundra (a vast, flat, treeless Arctic region of Europe, Asia, and North America in which the subsoil is permanently frozen)
    - - Low annual precipitation (50-350 mm) with most precipitation falling as snow
      - Small stores of moisture in the atmosphere due to low temperatures which reduce absolute humidity
      - Limited transpiration due to sparseness of vegetation cover and the short growing season
      - Seasonal changes
        
        Winter sub-zero temperatures prevent evapotranspiration, causing low humidity (and precipitation), some evapotranspiration takes place in the summer from the melting of the active layer (the seasonally thawed surface layer above the permafrost)
        
        Melting of permafrost in summer can lead to a sharp increase in river flow
      - Physical influences
        
        Drainage is poor, as the permafrost prevents water infiltrating the soils as well as due to the crystalline rocks that dominate tundra in Arctic Canada
        
        Erosion of the rock surface beneath the tundra has created a gently undulating plain with minimal relief, impeding drainage and contributing the waterlogging during the summer months
      - Effect on Water
        
        Melting of the permafrost increases run off and river discharge making flooding more likely
        
        This increases the number of wetlands, ponds and lakes, increasing evaporation
        
        The formation of quarries through strip mining create artificial lakes
        
        Drainage systems are interrupted by road construction and the foundations of buildings
    - - Permafrost is a big carbon sink, estimated to hold 1600 GT of carbon globally (held in air pockets and frozen plant material)
      - Stored carbon is accumulated due to low temperatures which slow down decomposition of plant and animal material
      - There is 5 times more carbon in tundra soils than in the above ground biomass
      - Despite it previously being a carbon sink, global warming is raising concerns that permafrost may now turn into a carbon source, as when it melts co2 (as well as methane, CH3) locked in ice cores formed in previous climates such as in the Ordovican period is released
      - This may however not be true as as temperatures increase more photosynthesis and plants growth means more carbon enters the soils (the net impact is disputed)
      - Seasonal changes
        
        In the winter low temperatures, low sunlight and unavailability of liquid water lead to a low NPP
        
        Plants grow rapidly during summer months with long daylight hours where they input carbon rich litter into the soils (only last 3 months)
        
        Overall net NPP is still less than 200g/ m2 annually
      - Oil and gas productions impact on Arctic tundra
        
        Extensive oil and gas reserves were discovered at Prudhoe bay in 1968 in Northern Alaska in 1968 - During the 70’s and 80’s pipelines, roads, gas processing facilities and gravel quarries were constructed to exploit the reserves
        
        By the early 1990’s the North slope accounted for nearly a quarter of the USA’s domestic oil production
        
        Today it continues to supply 6% of oil to the USA (has decreased due to high production costs and the growth in the shale industry in the USA)
      - Arctic National Wildlife Refuge (ANWR)
        
        ANWR is a 19-million-acre national wildlife refuge in NorthEastern Alaska
        
        There is huge pressure to drill in the area due to there being 12 billion barrels of crude as well as Prudhoe bay output of oil decreasing
        
        Trump relaxed legislation in 2017 to allow 2000 acres in the 1002 zone to be opened up for oil exploration and extraction
      - Effects on Carbon
        
        Has caused melting of the permafrost due to direct heating from the building of infrastructure, dust decomposition along roadsides creating darkened snow surfaces increasing light absorption as well as the removal of vegetation cover that insulates the permafrost from solar radiation
        
        It is estimated this has led to the release of 7-40 million tons of co2 per year and 24- 114 tonnes of methane per year
        
        The destruction of vegetation reduces co2 uptake
        
        Thawing soil increases microbial activity and decomposition rates (increasing atmospheric co2)
    - - Management strategies to reduce the impact of oil and gas production
        
        Roads and other infrastructure projects can be constructed on insulating ice or gravel pads, protecting the permafrost from melting
        
        Creating elevated buildings or pipelines to reduce heat emitted melting the permafrost
        
        Drilling laterally, enabling oil and gas to be accessed several km from the drilling site, reducing the need for as many roads, pipelines, quarries etc
        
        The use of more advanced computers to detect oil and gas bearing geological structures, meaning fewer exploration wells are needed
      - Strategies to reduce human impact on the carbon cycle
        
        Reduce carbon emissions through low carbon technology eg; the use of electric cars or renewable energy sources
        
        Carbon trading schemes
        
        Reforestation
        
        CCS
      - Strategies to reduce human impact on the water cycle
        
        Use low impact development (LID) techniques that help imitate the natural movement of water in the environment eg; use rain barrels in garden to store water for later use, green roofs (plant grass and shrubs on rooves)
        
        Reduce carbon emissions to prevent warming of oceans, increased evapotranspiration rates etc