How important are water and carbon to life on Earth? Flashcards
What is the key role of water in supporting life on Earth?
It allows organic molecules to mix and form more complex structures.
e.g water allows protein chains to fold in our bodies
What zone does Earth lie in that allows for the presence of liquid water?
‘Goldilocks zone’
region around a star where conditions are just right for liquid water
How do oceans moderate temperatures on Earth?
By absorbing heat, storing it, and releasing it slowly.
What percentage of the Earth’s surface do oceans occupy?
71 percent
What is the role of clouds in temperature moderation?
They reflect around a fifth of incoming solar radiation and lower surface temperatures.
What does water vapor do in terms of greenhouse gases?
It absorbs long-wave radiation from the Earth.
Fill in the blank: Water makes up _______ of all living organisms.
65-95 percent
What process do plants use to manufacture their own food?
Photosynthesis
What are the main uses of water for economic activity?
- Generate electricity
- Irrigate crops
- Provide recreational facilities
- Satisfy public demand
- Food manufacturing
- Brewing
- Paper making
- Steel making
What is the significance of carbon in life on Earth?
Life as we know it relies on carbon, forming large molecules like proteins, carbohydrates, and nucleic acids.
Where is carbon stored in the environment?
- Carbonate rocks
- Sea floor sediments
- Ocean water
- Atmosphere
- Biosphere
What are the two strands of the carbon cycle?
- Slow carbon cycle
- Fast carbon cycle
What is the average residence time of a water molecule in the atmosphere?
Nine days
What is the largest store of water on Earth?
Oceans
What is the primary process through which carbon is absorbed by plants?
Photosynthesis
True or False: The global water cycle is an open system.
False
What is the primary pathway for carbon in the carbon cycle?
- Photosynthesis
- Respiration
- Oxidation (e.g fossil fuels being broken down and released into the atmosphere)
- Weathering (e.g rocks breaking down and releasing carbon into the atmosphere)
What is the role of phytoplankton in the carbon cycle?
They absorb CO2 from the atmosphere through photosynthesis.
What is the average residence time for carbon held in rocks?
Around 150 million years
Fill in the blank: The global carbon cycle includes stores such as the atmosphere, oceans, and _______.
plant biomass
What percentage of global water is found in the atmosphere?
0.001 percent
How does water leave the atmosphere?
As precipitation
What is the primary method of water transfer from plants to the atmosphere?
Transpiration
What is the significance of fossil fuels in the carbon cycle?
They act as carbon sinks that endure for millions of years.
What is the slow carbon cycle?
- The long-term movement of carbon
- Includes rocks, soils, oceans, and the atmosphere
It contrasts with the fast carbon cycle, which includes processes like photosynthesis and respiration.
How can the global water cycle be regarded as a ‘closed system’?
- The total amount of water remains constant
- Water continuously cycles through evaporation, condensation, and precipitation
The water is not lost or gained; it merely changes states and locations.
Why is water vapour described as a ‘greenhouse gas’?
- It absorbs and emits infrared radiation
- It contributes to the greenhouse effect
- It regulates the Earth’s temperature.
It plays a significant role in climate and weather patterns.
What is an aquifer?
- A geological formation that can store and transmit groundwater
- Allows water to flow through it.
Critical for supplying freshwater for drinking and irrigation.
Distinguish between melting and sublimation.
Melting - where solid ice turns into liquid water
Sublimation - the transition of solid ice directly into water vapour
Sublimation is common in cold, dry conditions.
State two ways by which water is transferred from vegetation to the atmosphere.
- Transpiration through leaf pores (stomata)
- Interception loss from leaves and branches
These processes contribute to the moisture content in the atmosphere.
Outline the main differences between the fast and slow carbon cycles.
Give two examples for each
Fast cycle: involves rapid processes e.g:
- photosynthesis
- respiration
Slow cycle: involves long-term geological processes e.g:
- weathering
- sedimentation
The fast cycle operates on timescales of days to years, while the slow cycle operates over millennia.
What are phytoplankton and why are they important in the carbon cycle?
3 roles they play in the carbon cycle
Microscopic marine plants that:
- Perform photosynthesis
- Absorbing carbon dioxide
- Producing oxygen
As a result they are vital for the carbon cycle
They are a key component of oceanic ecosystems and contribute significantly to global carbon fixation.
What is the role of plate tectonics in the carbon cycle?
Cause movement of carbon between the Earth’s crust, atmosphere, and oceans through processes such as:
- Volcanic eruptions
- Formation of sedimentary rocks
This movement can sequester carbon over geological timescales.
What is the water balance equation?
(Flows of water in a drainage basin over time)
Precipitation (P) = Evapotranspiration (E) + Streamflow (Q) ± Storage
This equation summarizes the flows of water in a drainage basin over time.
What are the principal flows in the water cycle?
Name all 7
- Precipitation
- Evaporation
- Transpiration
- Run-off
- Infiltration
- Percolation
- Throughflow
These flows connect various stores of water within the cycle.
What are the main stores in the water cycle?
Name all 7
- Ocean
- Cryosphere
- Groundwater
- Surface water
- Soil moisture
- Atmosphere
These flows connect various stores of water within the cycle.
What forms can precipitation take?
- Rain
- Snow
- Hail
- Sleet
- Drizzle
Each form of precipitation affects the water cycle differently.
What impacts the intensity of precipitation?
(What defines “intensity” of precipiation + one potential effect)
The intensity of precipitation is influenced by the amount of water falling in a given time, with high-intensity events exceeding the soil’s infiltration capacity.
This can lead to rapid run-off and potential flooding.
What is the dew point?
The critical temperature at which air becomes saturated with water vapour, leading to condensation.
It is essential for cloud formation and precipitation processes.
What is transpiration?
The diffusion of water vapour from the stomata (leaf pores) of plants into the atmosphere.
It contributes significantly to atmospheric moisture.
What is condensation?
The phase change where water vapour changes to liquid water when air is cooled to its dew point.
This process is crucial for cloud formation.
What is the environmental lapse rate (ELR)?
The rate at which air temperature decreases with an increase in altitude, averaging about 6.5 °C per km.
It influences weather patterns and cloud formation.
What is the dry adiabatic lapse rate (DALR)?
The rate at which a parcel of dry air cools as it rises, approximately 10 °C per km.
This rate applies until condensation begins.
What is the saturated adiabatic lapse rate (SALR)?
The saturated adiabatic lapse rate (SALR) is the rate at which saturated air cools as it rises, approximately 7 °C per km, due to the release of latent heat during condensation.
This rate is lower than the DALR because of the heat released.
What is interception in the context of the water cycle?
Interception is the process where vegetation temporarily stores precipitation on leaves, branches, and stems before it either evaporates or reaches the ground as throughfall.
It affects the amount of water that reaches the soil.
What factors affect interception loss?
- Interception storage capacity
- Wind speed
- Vegetation type
- Tree species
These factors determine how much rainfall is intercepted and lost before reaching the ground.
What is groundwater flow?
Groundwater flow is the movement of water through soil and rock layers, which eventually emerges at the surface as springs or seepages.
It plays a crucial role in maintaining water supplies.
What is ablation in cryospheric processes?
Ablation is the loss of ice from snow, ice sheets, and glaciers due to melting, evaporation, and sublimation.
It contributes to river flow in high latitudes and mountains.
What is ablation in the context of cryospheric processes?
Ablation is the loss of ice from snow, ice sheets, and glaciers due to melting, evaporation, and sublimation.
What is the average flux of carbon from the atmosphere to land plants and phytoplankton via photosynthesis?
Around 120 gigatonnes (GT) a year.
What are the products of photosynthesis?
- Glucose * Oxygen
What is respiration in the carbon cycle?
The process in which carbohydrates fixed in photosynthesis are converted to CO2 and water.
What does the process of weathering involve?
The in situ breakdown of rocks at or near the Earth’s surface by chemical, physical, and biological processes.
What is carbonation?
A process where atmospheric CO2 dissolves in rainwater to form carbonic acid, which slowly dissolves limestone and chalk.
What is the role of decomposer organisms?
They break down dead organic matter, extracting energy and releasing CO2 back into the atmosphere.
What is combustion?
The reaction of organic material with oxygen that releases CO2 and other gases.
What are the two mechanisms by which oceans sequester carbon?
- Physical (inorganic) pump * Biological (organic) pump
How does the physical carbon pump operate?
It involves the mixing of surface and deep ocean waters, creating an even distribution of carbon through downwelling.
What is the biological pump in the context of oceans?
The process by which marine organisms, like phytoplankton, use sunlight and CO2 to produce organic material.
