Water & Carbon - Content

• Explain the concept of dynamic equilibrium in relation to the water cycle:

  • Dynamic equilibrium refers to the tendency towards a natural state of balance within the hydrological cycle (1)
  • The cycle is a closed system as no water enters or leaves the system (1)
  • The drainage basin element of the hydrological cycle is an open system where the inputs and outputs can change (1)(d)
  • The dynamic equilibrium is easily upset by extreme events such as storms (1)
• Explain the concept of negative feedback within the carbon cycle:

  • Feedback is an important aspect of systems and their tendency towards dynamic equilibrium (1)
  • Negative feedback nullifies a system towards equilibrium (1)
  • and counteracts the impact of earlier changes in the system (1)(d)
  • For example, increased atmospheric CO2 leads to both warmer temperatures and availability of CO2 for uptake by plants (1)
• Outline the relationship between the water cycle and the carbon cycle in the atmosphere.

  • Increasing concentrations of carbon in the atmosphere has a warming effect on the planet and leads to increased evaporation (1)
  • This can increase rates of precipitation or equally higher rates of evaporation can further exacerbate aridity (1) (d)
  • Volcanic eruptions release both carbon dioxide and water vapour into the atmosphere (1).
  • Photosynthesis requires both precipitation and carbon dioxide (1).
• Outline the process of decomposition in the carbon cycle.

  • Decomposition refers to the breakdown / decay of organic matter by bacteria or fungi (1).
  • Animals (such as worms), bacteria and fungi are collectively termed decomposers (1)(d).
  • During decomposition carbon dioxide is released (1).
  • Most of the carbon released into the atmosphere is as a result of decomposition (1)(d).
• Outline flows within the water cycle operating on a hill slope.

  • Surface runoff occurs when water runs directly over the ground (1)
  • This may occur if the soil is saturated. (1)(d)
  • Infiltration occurs when the water moves from the surface and then down through the soil horizons (1)
  • until it reaches the groundwater or an impermeable layer in the soil (1)(d).
• Explain the role of cryospheric change in the water cycle.

  • Cryospheric change has a regulatory role in sea levels (1).
  • The cryosphere is a major store of water (1).
  • In a period of cooling (glacial period) the cryosphere will grow in size (1).
  • This is because the water cycle is slowed considerably as the ice restricts the return of the water to the sea and ocean (d).
• Acidification:

  • The gradual reduction of pH of the oceans, due to dissolving carbon dioxide from the atmosphere
• Afforestation:

  • Planting trees and vegetation in the aim of increasing forest cover
• Anticyclone:

  • A system of high pressure, causing high temperatures and unseasonably high evaporation rates
• Aquifer:

  • A permeable or porous rock which stores water
• Biofuel:

  • Burning crops and vegetation for electricity and heat
• Carbon Capture and Storage (CCS):

  • The capture of carbon dioxide emissions directly from the factory, pumped into disused mines rather than being released into the atmosphere
• Carbon Fluxes:

  • The movement of carbon between stores
• Carbon Neutral:

  • A process that has no net addition of carbon dioxide to the environment
• Carbon Stores:

  • Places where carbon accumulates for a period of time such as rocks and plant matter
• Channel Flow:

  • Water flowing in a rivulet, stream or river
• Choke Points:

  • Points in the logistics of energy and fuel that are prone to restriction
• Combustion:

  • The process of burning a substance, in the presence of oxygen, to release energy
• Convectional Precipitation:

  • Solar radiation heats the air above the ground, causing it to rise, cool & condense forming precipitation (often as thunderstorms)
• Cryosphere:

  • The global water volume locked up within a frozen state (i.e. snow and ice)
• Decomposition:

  • The break down of matter, often by a decomposer which releases carbon dioxide through their own respiration
• Depression:

  • A system of low pressure, with fronts of precipitation where low and high pressure air masses meet
• Desalination Plant:

  • The conversion of seawater to freshwater, suitable for human consumption
• Desublimation:

  • The change of state of water from gas to solid, without being a liquid (the opposite process to sublimation)
• Drainage Basin:

  • The area of land drained by a river and its tributaries
• Drainage Density:

  • The total length of all rivers & streams divided by the area of the drainage basin
• Drought:

  • An extended period of deficient rainfall relative to the statistical average for the region (UN)
• Economic Water Scarcity:

  • When water resources are available but insufficient economic wealth limits access to it
• Energy Mix:

  • The composition of a country’s energy sources
• Energy Security:

  • The ownership and full control of a country’s energy source, production and transportation
• Energy Pathway:

  • The movement of energy from its extraction or source, through pipes, freight logistics or cabling
• Energy Players:

  • Key companies and individuals who own, distribute and sell energy and energy sources
• Enhanced Greenhouse Effect:

  • The build-up of greenhouse gases in the atmosphere, reducing the amount of solar radiation reflected into space
• ENSO Cycles:

  • El Nino Southern Oscillations - naturally occurring phenomena that involves the movement of warm water in the Equatorial Pacific
• Evapotranspiration:

  • The combined total moisture transferred from the Earth to the atmosphere, through evaporation and transpiration
• Frontal Precipitation:

  • Where air masses of different temperatures meet at a front, one mass will be forced over another, causing precipitation beneath the front
• Global Hydrological Cycle:

  • The continuous transfer of water between land, atmosphere and oceans. The Earth is a closed system
• Groundwater Flow:

  • Water moving horizontally through permeable or porous rock due to gravity
• Hydrological Drought:

  • Insufficient soil moisture to meet the needs of vegetation (crops, trees, plants) at a particular time
• Infiltration:

  • The movement of water vertically through the pores in soil