Carbon Cycle

  • Created by: Alemae
  • Created on: 30-05-18 10:45

The Stores of the Carbon Cycle


  • Biosphere - plants and animals - Ecosystems store 560PgC
  • Geosphere - rocks and ground -  stores 100,000,000 PgC
  • Hydrosphere - deep oceans store - 38,000 gC
  • Atmosphere - Co2 in air - stores 560 PgC

What unit do you measure carbon with                   -              Pg/Gt    or       PgC


  • Positive Feedback = do something, and it gets worse continually
  • Negative Fedback = restoring balance


  • Identify the 4 stores of carbon in the carbon cycle
  • What is positive feedback? Negative feedback?
  • How much does the geosphere store in carbon?
  • How much does ecosystems store?
  • How much does the atmosphere store? How much is stored in the deep oceans?
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Residential times of Carbon in Stores

Long term Stores:

  • Terrestrial geological (sedimentary rocks)
  • Deep ocean (dissolved and slowly cycled)

Short-term stores:

  • Terrestrial stores (breakdown of organic material) - can take days in hot conditions
  • Surface of ocean (exchanges with atmosphere and deep ocean) - plankton
  • Atmosphere - lifestime of up to 100 years
  • Terrestrial Ecosystems - storage of caron in trees and exchange with atmosphere


  • Give 2 examples of a long-term store
  • Identify 3 short-term stores
  • How long can carbon remain in the atmosphere?
  • How long can it take for organic materialto break down in hot conditions?
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The Geo-Sphere

  • Most carbon is stored geologically
  • This is through sedimentary rocks in the ocean to limestone, coal and shale (fuels) which has links to the bioshpere - organic material
  • Carbon is released from the geosphere through volcanic outgassing at subduction zones and chemical weathering
  • Caron stays there for a VERY long time (slow turnover - up to 100,000 years)


  • Where is most carbon stored on the Earth?
  • Give examples of how it is stored?
  • How is it released?
  • How long can carbon stay in the geo-sphere?
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  • Phyto-Plankton - sequester carbon from the atmosphere = passed through food chain as proteins and fats
  • Net Primary Producers play a large role as take in CO2 through photosynthesis = more global warming = more NPPs
  • Dead Crustations fall to sea bed and either dissolve or build up to make limestone - White Cliffs of Dover
  • Oceans - Thermohaline Current which contribute to global nutrient and CO2 cycles. Starts and ends in Artic. Takes 1,000 years for any cubic metre of water to travel through system. Shifts carbon from upper to deeper waters.
  • The planets food chain is dependent on cool, nutrient rich waters that support algae and seaweed growth
  • More than x2 CO2 can dissolve in cold polar water than in warm equatorial water
  • CO2 concentration is 10% higher in deep oceans than at surface


  • How do phyton-plankton contribute?
  • What impact will global warming have on NPPs? Why?
  • What builds up to make limestone? Example?
  • What current contributes to global nutrient and CO2 cycling in the ocean?
  • How long does it take for a cubic metre of water to travel through the current?
  • What is very important to the global food chain? Fact?
  • What is CO2 conentration like in the deep ocean?
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The Greenhouse Effect

Greenhouse effect - how the radiation from the atmosphere warms the planet's surface and air around it (enhanced means it is no longer balanced or sustainable for the health of the planet) Determines temperature and precipitation

What happens:

  • Solar radiation comes in to the atmosphere and some of it is rejected back out into the atmosphere, and the rest is absorbed, warming the Earth's surface and troposphere as its converted into heat
  • Around 69% of solar radiation is absorbed by the oceans or Earth's surface

Global warming - change?

  • Photosynthesis will increase
  • Warer oceans soless absorbed BUT more CO2 anyway = acidification
  • More CO2 in atmosphere
  • CO2 has increased in volume by 40% in the last 300 years


  • Explain the greenhouse effect. Why is it important
  • How much is absorbed by the oceans and Earth's atmosphere?
  • How will global warming change the carbon cycle?
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Tropical Forests - carbon store

Why they are good:

  • Rainforests have  x10 more leaf area than temperate forests
  • Only covers 6% of Earth but account for 50% of photosynthesis
  • Tree = 50% carbon


  • Agriculture/Cattle ranching/HEP/Minerals
  • Deforestation - 15% of all greenhouse gases are because of deforestation


  • May emit more carbon than they store and less of them (deforestation in Amazon and Indonesia)


  • What threats face rainforests? Fact?
  • Why are rainforests better than temperate forests?
  • What could happen in the future?
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Photosynthesis and soil health

Importance of photosynthesis

Photosynthesis helps regulate the amount of CO2 and so regulates the Earth's temperature. More productive in warm and wet conditions (global warming)

The Nutrient cycle and soil health

  • Soil health is dependent on the amount of organic carbon stored in it. Gives it water retention capacity, structure and fertility. 
  • Threat = soil erosion as affects carbon storage
  • Inputs to soil = plants and animals (biomass)
  • Outputs = decomposition, erosion, leaching, surface run off


  • Why is photosynthesis important in the carbon cycle?
  • What threats face soil health?
  • How does carbon aid soil health?
  • What are the inputs and outputs to the nutrient cycle?
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Fossil Fuel burning impact on the carbon cycle


  • Fosil fuels used since the Industrial Revolution
  • 1/2 of extra emissions of CO2 since 1750 have remained in the atmosphere

Potential Impacts - more source of carbon than sink?:

  • Loss of storage in unfreezing permafrost - Artic and Coral ecosystems at risk
  • Rising average sea level and storm surges may increase - ENSO impact
  • Some regions may become more wetter/drier and type of precipitation may be affected. = More floods and droughts
  • Affect Thermohaline current - slowing or reversing the Gulf Stream (keeps U..K temp 5 degrees higher than it would be in winter)
  • Biodiveristy at risk?
  • Amazon - 60% of precipitation orginate from evapotranpiration by upwind ecosystems


  • How has fossil fuel consumption impacted CO2 levels?
  • How will climate chnge affect the Thermohaline current? ENSO?
  • Other impacts of climate change?
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U.K. Energy Mix

  • The void left by the fall in coal use has been filled largely by a rapid rise in the use of natural gas and, to a lesser extent, an increase in electricity usage.
  • By 2030, it expects renewables to be by far the biggest source of energy used in electricity generation, making up about 40% of the overall mix.

  • In 2012, it accounted for less than half of all electricity (coal)

  • In 2012, we used less than 3 million tonnes of oil 

Why has it changed?

  • Technological advances and Environmental concerns – Kyoto Protocol/ Oil supplies OPEC

  • Recessions and the Global shift – service sector

  • 1990s – fall in coal use as people used cheap natural gas (North Sea) and privatisation of electrici and Miners Strike 1980 – coal use fell


  • What is expected to happen to renewables by 2030?
  • In 2012, how big was the coal industry in U.K?
  • In 2012, how much coal did we use? 
  • Identify some factors that have led to change in the U.K.'s energy mix
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What factors can impact on consumption of energy?


  • Physical availability (domestic or imported?)
  • Technology (can help access or encourage consumption)
  • Cost
  • Economic development (developed = greater consumption and perception)
  • Climate (cold or warm?)
  • Environmental priorities


  • Identify 4 factors that can impact the consumption of energy?
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Energy Players

Who influences energy consumption? (energy pathways)

  • TNCs - help with supply and consumption
  • OPEC - supply (owns 2/3s of world oil supply)
  • Governments and hteir policies environmentally
  • Consumers - demand
  • Shipping companies - supply and distribution
  • Pipeline controllers - supply
  • Pressure groups - supply and demand (pressures consumers and companies)


Identify the 5 main players in energy consumption

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Reliance on fossil fuels

Energy security

  • Russia - biggest land mass with lots of resources
  • China - Three Gorges Dam, links to other countries, gas oil reserves
  • Saudi Arabia - oil reserves, solar
  • Iceland - geo-thermal

Issues: renewability, demand, limited resources, politics, tectonic disasters

There is a problem as countries with high demand often don't have a large amount of resources to sustain their population. Hence...neo-colonialism (China)


  • Identify 4 countries with reasonable energy security
  • What issues are there with energy security?
  • What is the issue with developed countries?
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How can energy pathways be disrupted?


  • Russia is second largst producer of gas in world
  • Lots of gas exported to EU - three of those pipeines cross Ukraine (controls price for land)
  • Could become part of EU and join NATO
  • Could annexe Ukraine or move pipelines elsewhere (same position with Finland and Poland)


  • Middle East - frequent disputes and instabilities limit OPECs effectiviness and cohesion
  • Embargo against Iran – oil sales fallen 40% in 2011. Crippled Iran economy due to nuclear testing
  • Libyan Crisis – started in 2011 and has thousand of casualties. Civil war caused their oil economy to collapse despite having largest oil reserves of any African country
  • Religion – Saudi Arabia Sunni vs. Shiite Iran. Taken opposite sides in wars in Syria and Yemen
  • Controls 2/3 of world's proven oil reserves


  • How have OPEC and Russia threatened energy pathways and security?
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Unconventional energy sources

Tar Sands - Canada

  • 300 billion barrels of oil in tar sands = equivalent to Saudi Arabia oil reserves
  • Increase in population (by 2030 = 8bn) and so can provide energy without switch to new sources
  • 6 barrels of water per barrel of oil
  • Heavy oils in tar-sands produce x3 as much CO2 as light oils and deforestation
  • Canada vs. EU = Threat of trade war over EU going to label oils from Alberta oil sand highly polluting
  • First Nations – mercury poisoning

Fracking - BP

  • Gas security for Canada and USA for next 100 years
  • More money - $36 billion due to Shale gas added to GDP
  • Natural gas imports down 25% from 2007-2011 = less reliance
  • Water contamination of groundwater (Wind River Basin USA)
  • Cancer clusters – 95% that it increases childhood cancer and lymphoma in Flower Mound in USA
  • 4 million gallons of water used per well
  • Greenpeace critical and "Frack off" protest group in UK

Other alternatives- Shale Gas, Shale oil, etc. 

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Renewable energy - pros and cons


  • No greenhouse gases, reliable over 90% of the time, 
  • Provides over 11% of world's electricity
  • Risky (Fukishima Nuclear Power Plant 2011) and Chernobyl - radioactive
  • Uranium is a scarce resource = NOT SUSTAINABLE

Wind Power

  • Domestic surce of energy with no CO2 emissions
  • US wind sectore = employed more than 100,000 workers in 2016
  • Noisy and ugly - if built away from people, transmission lines needed
  • Kills birds

Solar Power

  • reneweable and sustainable - sun going to last for 6.5 billion years
  • Can sell surplus energy, low maintanence
  • Installation cost can be high - £4,000 - 7,000
  • Expensive storage batteries for nighttime
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Renewable energy in practice

Nuclear Energy

  • USA - In 2012 it provided 20% of USAs energy needs
  • USA biggest user followed by France
  • Generates 1/5 of U.K's energy presently

Wind Power

  • Best windpower in Europe - 11% of electricity in UK in 2015
  • Present in more than 90 countries

Solar Power

  • UK led Europe for solar growth in 2016 with 29% new capacity followed by Germany
  • Solar capacity rose 50% in 2016 globally
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Biofuels and other radical energy sources/solution

Biofuels - Brazil

  • 4% of energy comes from renewable sources
  • 90% of vehicles sold in Brazil now work on petrol and sugar can ethanol
  • Leading exporter of sugar and ethanol = deforestation - not so carbon neutral

Carbon capture

  • AKA. storing carbon underground in aquifers
  • Expensive - complex tech
  • Not sure if CO2 wil remain underground
  • Not sustainable - not solving root problem


  • Hindenburg Disaster - flammable
  • Water is waste product
  • Creates own fuel and water doesn't have to be freshwater
  • 95% of people in Iceland in favour of Hydrogen developemnt - no oil imports in Iceland
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Human Activity


  • 1/2 of all deforestation for soy,palm oil, beef and paper production
  • Approximately 13 million hectares deofrsted annually
  • Tropical forests lost 1/2 its area since 1960s


  • Beneficial for CO2 sequestration
  • Monoculture criticism (palm oil plantations) - often store less CO2 and disease-prone (China's Three-North Shelterbelt)
  • 2014 - New York Decleration 2014 = global target to restore 350 million hectares of forest by 2030

Grassland Conversion

  • Two main types of grassland = covering 26% of Earth's land
  • Only 2% of N. America's praries remain from land conversion
  • Used too intensively for animals and pasture
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Ocean Acidification


  • Up to early 1800s = pH of oceans 8.2 (alkaline) but in 2015 it was 8.1
  • More CO2 absorbed = more acidic (carbolic acid)
  • Might positively impact phytoplankton and seaweeds
  • Might impact food suppy in ecosystems
  • May threaten crustations - carbonate shells - likeoysters, mussels
  • More vulnerable to predators - less energy as have have to repair themelves more
  • Coral reefs around New Zealand under threat like Great Barrier Reef


  • How has the ph of oceans changed?
  • Why?
  • What positive impacts might it have?
  • What is under threat?
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Climate change impact on forests

Amazon Droughts:

  • 2005 - Amazon has worst drought ever
  • Wilfires for months
  • More than 100 million metric tonnes of CO2 released
  • Affects biodiversity


  • Enhanced greenhouse effect - fossil fuels
  • Strong El Nino's


  • When was Amazon's drought
  • What happened?
  • What did scientists blame it on?
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Impacts of Forest Loss


  • Over 1.6 bilion people depend on forests (90% of those in poor countries)
  • Source of 80% of biodiversity

Kuznet's Curve

  • Suggests that after industrialisation has happened - rising incomes reduce environmental imapacts
  • 1990-2015 - rate of deforestation slowed by 50%
  • 13% of forests classified as "conserved" (Brazil, USA, Europe and rise in Asia protecting forests through national parks)
  • Local communities protsting to save forests
  • Doesn't mean conservation in practice
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Increasing temperatures

What will increase in temperatures impact?

  • Precipitation patterns
  • River regimes
  • Cryosphere - shrinknig as a store of water and carbon
  • Drainage Basin Stores


  • Average Artic temperatures rose twice as fst as global temperatures
  • Huge implications for currents, air circulation, sea level rise and flooding
  • Artic stores more carbon than any other region - 5-14% of total oceanic stores
  • Artic Albedo - reflective for solar radiation
  • Methane hydrants found in permafrost - 25% more powerful as greenhouse gas than CO2
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Threats to Ocean Health

Climate change impacts

  • Beaching and Acidification
  • Rising sea levels and Loss of sea ice

Affects everything - food supply, bredding, migration patterns..

Why is ocean health important?

  • Marine fishing industry globalised - trade
  • Culture choice - Japan and iceland
  • Necessity - poorer countries Namibia
  • Fish provdes 16% of annual protein consumption for 3 bilion people
  • 6% of GDP globally is from fish

Most affected:

  • Maldives, Iran, Libya... (most affected = less developed and less responsible)
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An Uncertain Future

Risks from Climate change:

  • Large-scale release of CO2
  • Uncertainty = procrastination
  • CO2 levels sampled weekly at 100 different sites around the world - tech
  • Increase in disasters - droughts/famines/cyclones/heatwaves
  • Sea Level Rise - loss of cultures (Tuvalu/Maldives)
  • Temperature up - changes in precipitation, water circulation, salinity, acidification

Why is it happening?

  • Land Use changes (deforestation, urbanisation, impermeable)
  • Fossil fuel burning (transport, heating, industry, agriculture)
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Adaption strategies

Adaption techniques

  • Water conservation - less abstraction and resources used. use more grey water. BUT...can't match demand and cultural habits need changing via governments and TNCs
  • Resilient agricultural systems - drought resistant species = help resistance to disease and drought. Better prctices = les soil erosion and more sequestration. BUT... genetic modification still debated ethically and high costs which subsistance farmers can't afford
  • Land-Use Planning - strict controls on where buildings can be built. BUT...Public apathy. Not always feasible - Tokyo, Japan
  • Flood-risk management - can reduce flod risk like permeable tarmac and reduced deforestation...BUT hard to fund during recessions and thebelief that technology cannot always fit everything (river dredging)
  • Solar Radiation - orbiting satalites to reflect radiation back can cool earth...fairly cheap in comparison to mitigation BUT untested and wouldn't fix everything like acidification and could have consequences
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Mitigation methods

Mitigation in U.K. 

  • Carbon taxation - carbon price floor tax = minimum price for compnies to emit CO2. Frozen in 2015. Lower road taxes for low-carbon-emitting cars scrapped in 2015
  • Renewable switching - switching to renewable energy (Wind energy)
  • Energy Efficiency - Green Deal Scheme = encouraged energy-saving improvements to home like boilers. Scrapped in 2015
  • Afforestation - Big tree Plant - encourages companies to plant 1 million new trees. National Trust. Woodland Trust.
  • Carbon capture and storage - Canada's Boundary Dam = only large-scale working scheme. 2015 = UK cancelled its investment into it at coal and gas stations. 
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Kyoto Protocol

Date = 1997


  • Operates until 2020
  • Started global approach to climate change
  • Paved way for low carbon legislation like U.K. 2008 Climate Change Act
  • China slowing emissions
  • By 2012- emissiond 22.6% lower than 1990 levels


  • Slow ratification - some withdrew like Japan and USA
  • Non-industrialised countries not asked to sign
  • Emission reductions may be due to other factors like global shift, less use of coal 
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