Carbon Flashcards
Define “biogeochemical” carbon cycle
- Biological cycle: fast, sequestration between atmosphere, ocean, sediment etc.
- Geological cycle: organic matter buried in sediments + takes millions of years to form fossil fuels, carbon from volcanic emission, erosion/formation of sediment on seafloor
- Chemical: carbon is a non-metal element, can be part of human life, 4th most abundant in world
What are the three carbon stores?
- Terrestrial: in the lithosphere (sedimentary rocks), biosphere (organisms +biomass broken down by micro-organisms into CO2, organic storage)
- Atmosphere: rapid interchange with terrestrial
- Ocean: hydrosphere, dissolve in deep ocean and at surface
How do annual fluxes of carbon vary in rate?
- Stable when outputs/inputs are not beyond threshold, equilibrium
- Small change = shift and amplify feedback loops
How does carbon form sedimentary carbonate rocks?
- Limestone = calcium carbonate
- Carbon extracted from ocean by phytoplankton/marine creatures through photosynthesis
- Shells/skeletons cement w heat + pressure to form limestone on ocean floor
How is carbon biologically derived in shale and coal?
- Remains of non-skeletal organic material decay in anaerobic conditions, forming hydrocarbon chains, crude oil stored in pores of shale
- Coal formed from remains of trees and plants
- Organic material from swamps become peat, converted to coal w heat/pressure
How are phytoplankton part of the biological pump?
- They sequester CO2 during photosynthesis which becomes organic matter
- Dead cells sink, carbon transported to deep ocean and decay releases CO2 there
What is the carbonate pump?
- Sediment that sinks to the seabed gradually transforms into rock which remains there for geological epochs
(Ocean stores more carbon)
What is the thermohaline circulation?
- Cold water holds more gas
- Warm tropic water moving towards poles evaporates, leaving cold/salty water
- It’s dense/heavy so sinks to bottom of ocean
- Carbon pump = sinks and pushes the deep water away (forms N Atlantic deep water)
- Cold water recharged by Antarctic water (big carbon sink)
What do terrestrial primary producers do?
- Land based absorption of carbon
- Stores in leaves, roots, bark until needed
- Converts carbon into carbs during photosynthesis
How is biological carbon stored as dead organic matter in soils?
- Vegetation accumulates and compresses (partially degraded), trapping carbon
- Held in anaerobic conditions as it’s locked in (waterlogged) peatlands
- Drying up = aerobic conditions, soil biota decompose veg and respire carbon into atmosphere
- Burning = release methane, traps more carbon in atmosphere
What is the concentration of atmospheric carbon like?
- Natural carbon release after Ice Age
- More phytoplankton growth increases CO2 sequestration
- Permafrost melt = methane release, trap light waves, increase temp (+ve feedback)
How does natural GHG effect determine temperature and precipitation distribution?
- GHGs increase temp, increasing precipitation and clouds
- Leads to albedo effect with increase in reflection, decreasing temp
What is Net Primary Productivity?
- The rate of generation of biomass
- Linked to growth and how many nutrients are stored in the biosphere
How does terrestrial photosynthesis and storage of carbon vary between biomes?
- Depends on latitude due to temp and precip
- Tropical: large biomass, high decomposition + instant nutrient uptake = less carbon in litter+soil
- Temperate: more organic matter in soil = higher capacity to store carbon (biota respire through decomposition)
- Taiga: Slow decomposition + frozen upper soil so soil biota cannot respire much
How does ocean photosynthesis regulate carbon in the atmosphere?
- Tropic water is stratified so surface water is nutrient poor due to evaporation
- Polar regions have mixed surface/deep water so nutrients available all year
- Light for photosynthesis decreases with depth (less sequestration)
- Coastal estuaries = most production (shallow + carbon from erosion)
- Open ocean also high due to size
How is soil health influenced by stored carbon?
- Stores 30% of global carbon but local conditions determine sequestration and emission
- Clay-rich soils hold more as it protects carbon from decomposition by biota
- Soil erosion removes carbon from active surface layer
- Depends on weathering and decomposition
How has fossil fuel combustion altered the balance of carbon pathways?
- Anthropogenic climate change
- Carbon transferred from fossil stores to atmosphere, accelerated carbon exchanges
- Combined with natural changes (albedo effect, Milankovitch cycle etc)
What is energy consumption?
- Total energy use
- Industrialisation/urbanisation = power grids, increased population, increase household wealth
- Consumption decreases due to env concerns + efficient appliances
What is an energy mix?
- Proportion of each type of primary resource that the country utilises within a year
- More than 80% is fossil fuels
What is energy transition?
- Changes from pre-industrialised, industrialising, industrialised, post-industrial
- Causes change in energy mix
- Slow due to geopolitical tensions
What is domestic vs foreign energy?
- Internally produced
- Imported, dependency
What is primary and secondary energy?
- Primary = original source of energy (coal, oil, wind)
- Secondary is converted from primary energy into a form that energy can be consumed in (electricity)
What is renewable and non-renewable energy?
- Renewable is when the source is not depleted when used (wind, water, sun)
- Non-renewable is when the source is finite, the resource is not replenished at the rate of consumption (biomass, fossil fuels)
What is Dutch disease?
- One resource dominates econ, is exported and other countries buy it
- Lots of foreign currency comes in and the nation’s currency value increases
- Second resource wanting to export is harder (expensive for others to buy)
- Second industry dies out, reinforces cycle
What is the physical availability of Mozambique’s energy resources?
- Secure: 130bn m3 of gas, world’s 4th largest reserve
- Insecure: Only 4bn exploited so far, majority exported to S Africa
What is the cost of Mozambique’s energy resources?
- Secure: $350bn of potential resources, tax rules on resource sales leading to $1bn in 2013
- Insecure: TNCs can’t wait 3yrs to sort out tax + concession agreements
What is the technology needed for Mozambique’s energy resources?
- Secure: countries such as India and China want to invest in oil, gas and infrastructure (possible $10bn over 3yrs)
- Insecure: after infrastructure spending, only £13bn left of total worth of energy sources
What is the public perception of Mozambique’s energy usage?
- Secure: concerned abt gov exploitation of resources (helps in ST)
- Insecure: may go against gov if corruption continues
What is the effect of level of econ dev on Mozambique’s energy resources?
- Secure: 7% GDP growth rate and increasingly educated young population
- Insecure: civil war left 55% below poverty line w/ illiterate population not knowing land rights
What are the environmental priorities in relation to Mozambique’s energy resources?
- Young people feel gov isn’t doing enough to protect env
- ST opposition but LT can improve management
What is the role of TNCs in energy pathway and supply?
- Nearly half of oil + gas companies are state owned, not technically TNCs
- Involved in a range of operations: extract, transport, refine and produce petrochemicals
- Pathway = energy flows from area of high supply to high demand
What is the role of OPEC in energy pathway and supply?
- Manage prices to control global crises and prevent undercutting
- 12 members and own 2/3 of global reserves
- Control amt entering the market and accused of reducing production to increase prices
- Organisation of Petroleum Exporting Countries
What is the role of consumers in energy pathway and supply?
- Encompasses all people but the most influential are: domestic users, transport, industry
- Passive players for fixing energy prices
What is the role of governments in energy pathway and supply?
- Number of roles
- Guardians of national energy security and influence energy sourcing for geopolitical reasons
What does the shift to renewable and recyclable energy involve?
- IPCC wants to treble renewable output by 2050
- Wind power lacks consistency and depends on location
- Japan are uncertain about recyclable energy so decreased nuclear
- Requires complex tech, issue of safety + waste (long decay life)
What is decoupling?
- The ability to maintain economic development whilst reducing env damage
- Moving away from fossil fuels
- Represented by environmental Kuznets Curve
What are the economic costs/benefits of renewables (+recyclables)?
- Low oil and gas prices make it expensive
- Biggest problem is price of producing and selling
- Orgs such as Nordpool allow sharing of excess energy through reciprocal agreements
What are the social costs/benefits of renewables (+recyclables)?
- Majority agree with the idea until farms are proposed to be built near them
- NIMBYism
- But personal wind turbines save $3000/yr on electricity bill
What are the env costs/benefits of renewables (+recyclables)?
- Need to drown rivers to form HEP reservoirs
- Large areas of land covered by solar/wind farms
- No pollution or extractions
What are biofuels?
- Uses biomass to replace petrol, renewable source
- Converted into ethanol or biodiesel
- Recognised as a way to reduce fossil fuels + CO2
- Mainly includes wheat, maize, sugar cane, soy beans
What implications do biofuels have for food supply?
- First gen biofuels use food stock which replaces food sources
- Worse for countries with high levels of poverty
- Fertilised = eutrophication, fish die and contaminated water
Why is there uncertainty over whether biofuels are carbon neutral?
- The CO2 is produced when biomass is burnt is only what was sequestered whilst it was growing
- But there’s deforestation of land to grow the crops
- The amt absorbed by crops is less than previous vegetation e.g. Brazil/Amazon
- Also deforestation for displaced agriculture
How does nuclear energy work? (Radical tech)
- Uranium filled fuel pellets are placed alongside water-filled cylinders
- Uranium produces heat that makes steam, steam = energy to turn turbines to generate electricity
How is nuclear energy waste used?
- Waste is radioactive plutonium
- Mixed with thorium for new pellets
- Holds energy that is worth 800L of diesel
- Sustainable and produces 4 time more energy than the initial pellet
How does carbon capture and storage work?
- Capture CO2 emitted by fossil fuels
- Compress it into liquid
- Transported to storage site
- Deep underground rock (porous rock with a caprock) = Geo sequestration
- Monitoring system for CO2 levels at site
How do hydrogen fuel cells work?
- Electrolysis of water produces H2 used in a fuel cell and O2 is a byproduct
- But need electricity for it (renewables or GHGs?)
- Hard to store safely but is cheap, no environmental danger and has many uses
- For electric cars, limited range
How does CC affect the oceans
- Ocean acidification: ecosystem damage, biodiversity loss
- Coral bleaching: coral polyp needs energy, symbiotic rship with algae (sunlight energy), algae migrates when temp increases and polyps die
- Coral for tourism, food supply, protection
- SLR: thermal expansion, glacial melt, coastal flooding
- Storm surges: LP systems
What is needed for countries to be successful in decoupling?
- High GDP, developed economy, post industrial
- Private and public investment, good governance
- Research and technology for infrastructure
- Good location
- Reduce consumption (education, change habits, efficiency)
- Tax, incentives, subsidies
What is water management and its costs? (Adaptation)
- Reduce, reuse, recycle, high tech conservation
- Needs good gov and attitudes e.g. Singapore
- Costs: need stable government for policies, hard with population growth + demand, no over-abstraction solution in Lower Mekong with transboundary conflicts
What is resilient agricultural systems and its costs? (Adaptation)
- High tech drought tolerant species or low tech better practices e.g. crop rotation
- Includes food systems e.g. lab meat, plant alternatives
- Costs: high energy cost for indoor farming, expensive tech unavailable to poor subsistence farmers, food insecurity = quick fixes that don’t consider LT sustainability
- Easy to implement in developing countries
What is land-use planning and its costs? (Adaptation)
- Zone areas of risk so there are no people or property, resilient infrastructure design in other areas
- Need restrictions and laws for vulnerable areas
- Costs: infeasible in coastal megacities, requires strong enforcement and compensation, public antipathy
What is flood-risk management and its costs? (Adaptation)
- Hard engineering for localised flooding, soft engineering e.g. afforestation, high tech solutions e.g. permeable tarmac
- Flood resistant housing, relocations, monitor reservoirs
- Costs: landowners demanding compensation, reduced property values in rezoned areas, techno-fix culture interferes with nature, constant maintenance needed
What is solar radiation management and its costs? (Adaptation)
- Increase reflection before radiation reaches surface (seawater into atmosphere for condensation and cloud coverage, albedo effect)
- Costs: not tested, don’t understand possible positive feedback, unpredictable weather changes
- More mitigation than adaptation
Strengths of global climate agreements (mitigation)
- Montreal Protocol led to eliminating 99% of ozone-depleting substances
- Progress can occur through smaller groups and by sector: 600 local US governments have detailed climate action plans, investors put money into climate-friendly funds
Weaknesses of global climate agreements (mitigation)
- Kyoto Protocol and Paris Agreement: agree to reduce GHGs but CO2 in atmosphere is rising
- No enforcement mechanisms to ensure countries meet their own Paris targets + pledges aren’t ambitious or quick enough
- Disagreement on how to set priorities, developed/developing countries blame each other
Threats and opportunities of global climate agreements (mitigation)
- Ineffective agreements will have consequences including SLR, floods + species loss
- Above 1.5°C will lead to coral bleaching, ocean acidification, Arctic ice thaw
- Opportunities: COP and UNFCC led to Kyoto and Paris, climate club that penalises countries or treaties that apply to specific emissions or sectors
What is ocean acidification?
- 40% of CO2 produced by humans dissolves in the ocean, pH increases
- CO2 reacts with water and a chain of reactions leads to release of hydrogen ions which increases acidity
Why is ocean acidification a problem?
- Current acidification is similar to a greenhouse event
- Leads to extinction at vital levels of ecosystem production and threatens biodiversity (fish immunity and destroys coral)
- Skeletons formed with dissolved calcium carbonate but carbonate ions and hydrogen forms bicarbonate
- Less calcium carbonate to grow and repair
Complications of climate models/future projections
- Spatial variation
- Change over time
- Positive feedback
- Unknown research and development
- Severity, knock on effects
- Govmt policies
