Water and Carbon

Question 1

What are the global stores of water?

Answer 1

Hydrosphere
Cryosphere
Lithosphere
Atmosphere

Question 2

Talk about the hydrosphere

Answer 2

Hydrosphere – This includes all liquid water on Earth, such as oceans, lakes, and rivers. Oceans account for 96.5% of all global water but are saline and not suitable for human consumption.

Question 3

Talk about the cryosphere

Answer 3

Cryosphere – Composed of frozen water in glaciers, ice sheets, permafrost, and seasonal snow. 69% of all freshwater is stored here, but it is mostly inaccessible.

Question 4

Talk about the Lithosphere

Answer 4

Lithosphere – Water stored in rocks and underground aquifers, making up approximately 1.7% of Earth’s total water. Groundwater is a critical source for many regions, especially in arid climates.

Question 5

Talk about the atmosphere

Answer 5

Atmosphere – This is the smallest store, containing just 0.001% of global water in the form of water vapor. Despite its small size, it plays a crucial role in driving weather patterns and precipitation.

Question 6

How is freshwater distribute among the different stores? include %

Answer 6

Only 2.5% of global water is freshwater.
Within this freshwater fraction:
-69% is locked in the cryosphere (frozen in glaciers and ice sheets).
- 30% is stored as groundwater within the lithosphere.
-Surface and other freshwater sources account for only about 1% of global water stores.

Question 7

Talk about the different local water stores and how long they retain water.

Answer 7

Aquifers: Underground water stores can retain water from 200 to 10,000 years.

Glaciers: Typically store water for 20 to 100 years; they feed lakes that store water for 50 to 100 years.

Seasonal Snow and Rivers: Generally hold water for 2 to 6 months.

Soil Water: Holds water for only 1 to 2 months.

Question 8

Define the components of the cryosphere and their significance in the global water cycle

Answer 8

Ice Sheets: Massive glaciers covering more than 50,000 km²; only two exist in the world and they hold about 99% of Earth’s freshwater in frozen form.

Ice Caps: Smaller than ice sheets (less than 50,000 km²).

Alpine Glaciers: Found on mountain regions.

Permafrost: Soil that remains frozen for extended periods.

Sea Ice: Frozen ocean water.
The cryosphere is vital not only for water storage but also for regulating global climate patterns.

Question 9

What are the flows which drive changes in local stores of water?

Answer 9

Evaporation, condensation, infiltration, percolation, throughflow, surface runoff, groundwater flow, streamflow, and stemflow.

Question 10

What are the global processes which drive changes in stores of water?

Answer 10

Climate change (altering temperature and precipitation patterns), atmospheric circulation (affecting cloud formation and precipitation types), and cryospheric processes (e.g., ice melting and calving).

Question 11

Talk about local processes which drive changes in stores

Answer 11

Land use changes such as deforestation, urbanization, and agricultural practices (which alter infiltration, surface storage, and runoff).

Question 12

What are the global processes influencing the magnitude of water stores

Answer 12

Climate change
Clouds and Percipitation
Cryospheric processes
Storm events
Seasonal Changes

Question 13

Talk about climate change as a factor influencing global water stores

Answer 13

During the ice age, roughly a third of the Earth’s surface was covered in ice sheets and glaciers. This increased the magitude of crysospheres stores and lowered the hydrospheres store and seal levels were over 100m lower than present day.

Question 14

Talk about Clouds and Precipitation as a factor influencing global water stores

Answer 14

The global atmospheric circulation drives the formation of clouds and type of precipitation. The equator recieves more insolation and higher temperatures causing high rates of evaporation so the warm air rises. As it rises, it cools and condenses forming banks of towering clouds and heavy rainfall-

Question 15

How does the cryosphere influence the hydrosphere

Answer 15

The second largest store of water is ice and 95% is locked as the ice sheets of Antarctica and Greenland Any changes to the size (magnitude) of these sheets impact globally. The total melting of the ice sheets could result in a 60 m sea level rise, which is a lot of stored water. Melting of the ice sheets adds water to the hydrosphere store of the oceans. Ice shelves are further destabilized, which triggers ice calving, these icebergs subsequently melt; adding to the hydrosphere store and rising sea levels. This is a positive feedback loop

Question 16

Talk about Storm Events as a factor influencing global water stores

Answer 16

large amounts of rainfall saturates soil so infiltration cant occur increasing surface runoff.

Question 17

Talk about seasonal changes as a factor influencing global water stores

Answer 17

Spring + summer- More vegetation so more interception, ad less rainfall so hard, impermeable ground therefore more surface runoff, Autumn and Winter- less vegetation, and more rainfall. Frozen ground may be impermeable. Snow takes time to melt so increases lagtime

Question 18

What are the local processes influencing global water stores?

Answer 18

Deforestation
Agriculture
Urbanisation
Irrigation- water abstraction

Question 19

Talk about deforestation as a factor influencing global water stores

Answer 19

less interception by trees so surface runoff increases. The soil is no longer held together by roots so soil water decreases and transpiration decreases

Question 20

Talk about Agriculture as a factor influencing water stores

Answer 20

Pastoral Farming- relating to livestock, trample the ground reducing infiltration. Arable Farming- ploughing increases infiltration as looser soil which decreases surface runoff however digging ditches increases surface runoff. Irrigation- moving water by human intervention, can lead to groundwater depletion

Question 21

Talk about urbanisation as a factor influencing water stores

Answer 21

impermeable surfaces reduce infiltration and increases surface runoff reducing lag-time and increasing flood risk.

Question 22

Talk about irrigation and water abstraction as a factor influencing water stores

Answer 22

Irrigation can deplete groundwater supplies (e.g., the Ogallala Aquifer, USA).

Water Abstraction- reduces volume of water surface stores. Increases in drier seasons. lowers water table

Question 23

Talk about the concept of a drainage basin and explain why it is considered as an open system

Answer 23

A drainage basin is the land area drained by a river and its tributaries. It is considered an open system because:
Inputs: Water is gained through precipitation (including relief, frontal, and convectional rainfall).
Outputs: Water is lost through processes like evapotranspiration and runoff.
Stores: Water is held in various forms such as soil water, groundwater, river channels, and interception on vegetation.
This balance of inputs and outputs can vary, affecting local water storage and leading to phenomena like droughts or floods.

Question 24

What is the water balance equation?

Answer 24

PRECIPITATION = TOTAL RUNOFF + EVAPORATION ± STORAGE CHANGE

Question 25

what is the water balance dependent on?

Answer 25

The water balance of an area will change dependent on the physical factors especially during seasonal variation of temperature and precipitation which effects the change in storage. It can be applied to explain droughts and floods.

Question 26

What factors influence the soil water budget and why does it vary annually?

Answer 26

The soil water budget represents the balance between inputs (precipitation) and outputs (evapotranspiration) that affect soil water storage. Its variability is influenced by: Annual weather patterns (amount of rainfall versus dry periods). Soil characteristics such as type, depth, and permeability. Land use practices that alter the natural infiltration and storage capacity. These factors together determine whether a season results in a water surplus or deficit.

Question 27

What is a flood hydrograph?

Answer 27

A flood hydrograph is a graphical representation of a river’s discharge in response to rainfall

Question 28

What are the key components of flood hydrographs?

Answer 28

Discharge: The volume of water passing a point per second (measured in cumecs). Rising Limb: The portion where discharge is increasing. Falling Limb: The portion where discharge decreases after the peak. Lag-Time: The delay between peak rainfall and peak river discharge. Baseflow: The underlying flow from groundwater. Stormflow: The rapid overland flow and throughflow from intense rainfall.

Question 29

What natural factors influence runoff variations and flood hydrograph characteristics?

Answer 29

Rainfall Intensity: High intensity can quickly saturate soil, reducing infiltration and increasing surface runoff. Geology: Impermeable surfaces or geology with low permeability enhances throughflow. Drainage Density and Basin Size: Smaller, circular basins with high drainage density allow water to reach the central channel faster, reducing lag-time. Temperature: Lower temperatures reduce evapotranspiration, leading to higher runoff. Vegetation Cover: Forests intercept rainfall, reducing runoff and dampening peak discharge.

Question 30

In what ways do water and carbon cycles interact?

Answer 30

Phytoplankton Activity: Warmer ocean temperatures initially boost phytoplankton growth, which absorbs CO₂ and releases dimethylsulphide (DMS) that increases cloud formation and cools ocean surfaces. Ocean Acidification: Over time, increased CO₂ absorption lowers ocean pH, adversely affecting organisms like molluscs that rely on bicarbonate ions for shell formation, thus reducing the ocean’s capacity as a carbon reservoir.

Question 31

Talk about the feedback loops of both carbon and water cycles.

Answer 31

Changes in water temperature and circulation patterns influence both water storage and carbon sequestration, creating complex feedback loops that affect global climate.

Question 32

What is the importance of carbon?

Answer 32

Carbon is an essential building block for all life on Earth by playing a major role in regulating global climate particularly temperature and the acidity of rain.

Question 33

Name some forms of carbon?

Answer 33

- Carbon Dioxide- gas found in oceans, soils and the atmosphere and as a waste product. - Methane- greenhouse gas found in rocks, oceans and soils. - Hydrocarbon- found in sedimentary rocks. - Calcium Carbonate- common substance found in limesrone rock and shells. - Carbon Biomolecules- organic molecles forming 50% of dry mass

Question 34

Talk about the lithosphere as a store of carbon

Answer 34

Rocks, Fossil Fuels, Soils - 100,000 GtC The largest store, mainly as sedimentary rocks (limestone) and fossil fuels (coal, oil, gas). Extraction and combustion release stored carbon into the atmosphere.

Question 35

Talk about the hydrosphere as a store of carbon

Answer 35

Oceans - 38,000 GtC Oceans store carbon as dissolved CO₂, organic matter, and deep-sea sediments. They generate ~50% of the Earth’s oxygen, absorb 25% of CO₂ emissions, and capture 90% of excess heat; warmer waters hold less CO₂, exacerbating climate change.

Question 36

Talk about the cryosphere as a store of carbon

Answer 36

Ice, Permafrost - 1,500 GtC Carbon is locked in ice and permafrost. Melting releases both carbon and methane, creating a positive feedback that amplifies global warming.

Question 37

Talk about the biosphere as a store of carbon

Answer 37

Includes living organisms and organic matter in soils. Forests, especially tropical and mangroves, are key carbon sinks; deforestation reduces their capacity to sequester CO₂.

Question 38

Talk about the atmosphere as a store of carbon

Answer 38

CO2, Methane, other gases - 560 GtC Acts as the medium regulating Earth’s climate; human activities have increased CO₂ levels significantly since 1950, driving global temperature rises.

Question 39

Talk about processes driving changes in carbon stores at plant scale

Answer 39

Photosynthesis: Plants convert CO₂ and water into glucose and oxygen using sunlight, temporarily storing carbon in biomass. Respiration: Both plants and animals respire, converting glucose and oxygen back into CO₂, which is released into the atmosphere.

Question 40

Talk about the processes driving changes in carbon stores at sere scale

Answer 40

Vegetation Succession: The process on bare rock where pioneer species colonize and gradually lead to a climax community; carbon cycling becomes more complex with numerous transfers among plants, soils, and organic matter. Decomposition: Dead organic matter is broken down by decomposers, returning CO₂ to the atmosphere or soil. Combustion: Wildfires (natural or human-induced) release stored carbon back into the atmosphere through burning.

Question 41

Talk about processes driving changes in carbon stores at continental scale

Answer 41

Ocean–Atmosphere Exchanges: Oceans absorb CO₂ via diffusion; the physical pump (thermohaline circulation) and burial processes (e.g., formation of limestone from shells) redistribute carbon globally. Weathering and Erosion: Carbonation weathering (rainwater mixed with CO₂ forming carbonic acid) breaks down rocks, transferring carbon from lithosphere to hydrosphere.

Question 42

Talk about ocean processes and carbon dioxide

Answer 42

Physical Pump- CO2 is taken from the surface via diffusion into the deep ocean stores via currents. Thermohalne citculation distributes carbon around the planet. Cold water absorbs more carbon so as water moves toward the poles more Co2 is absorbed. Burial and compaction- Corals and other shelled sea creatures take C02 from the water and convert it into calcium carbonate to form shells. When they die they accumulate on the sea beds. Some dissolve releasing C02 and some compact into limestone.

Question 43

Talk about natural climate change as an impact on the carbon cycle

Answer 43

During the Quaternary, climates oscillated between glacial and interglacial periods—patterns reflected in ice core CO₂ records. Higher CO₂ levels enhance the greenhouse effect, raising temperatures and triggering permafrost melt, increased plant growth, droughts, reduced albedo, and more wildfires, which in turn influence CO₂ levels. Conversely, glacial periods lock CO₂ in ice, and reduced photosynthesis and decomposition lower atmospheric CO₂, weakening the greenhouse effect.

Question 44

Talk about cold and warm climates as an impact on the carbon cycle

Answer 44

**Cold Conditions-** cold water can hold more Co2. However, it can also freeze exposing more rock to chemical weathering. Respiration and photosynthesis processes are reduced by cold conditions and decomposers effectivness reduces. **Warmer Conditions-** This increases the rate of decomposition increasing carbon transfer. Warm conditions melt permafrost releasing carbon. This enhances the greenhouse effect and atmospheric warming- positive feedback

Question 45

Talk about wildfires as an impact on the carbon cycle

Answer 45

Transfer carbon from biosphere to atmosphere as CO2 is released through burning. They have an important role in the carbon cycle as they can encourage the growth of plants in the long-term due to the release of nutrient rich ash. There is much debate due to wether we should extinguish human activities as global warming is providing better conditions for wildfires to occur.

Question 46

Talk about the volcanic activity as an impact on the carbon cycle

Answer 46

Carbon stores within the eartg is released during volcanic eruptions mainly as gas. They contribute a relativley low proportion of CO2 to overall carbon cycleThe 1815 Mt Tambora eruption in Indonesia produced so much sulfuric dioxide gas, it blocked radiation from the sun lowering global temperatures bu 0.7 degrees. In this way, volcanos can influence the carbon cycle y reducing photosynthesis rates. over 130 million metric tonnes a year

Question 47

Talk about fossil fuel extracton and combustion

Answer 47

Hydrocarbons store carbon in the lithosphere for long periods. Carbon from the atmosphere is used by marine organisms to form shells and skeletons, which, after death, sink and become fossil fuels over time. Humans have long extracted these fuels for energy, but the rate has significantly increased, moving carbon from the lithosphere to the atmosphere. Industries like Canada’s tar sands now contribute to about half of global carbon emissions.

Question 48

Talk about burning hydrocarbons as an impact on the carbon cycle

Answer 48

Burning fossil fuels disrupts the climate. CO₂ levels rose from 320 ppm in the 1960s to over 418 ppm by 2022—the highest ever recorded. Before industrialisation, CO₂ levels were stable and cyclical. Now, greenhouse gases like CO₂, methane, and water vapour trap more heat. Human activities have driven nearly all greenhouse gas increases over the last 150 years.

Question 49

Talk about land use as an impact on the carbon cycle

Answer 49

- Deforestation- used to clear for farming and housing. - Farming Practices- Pastoral farming releases C02 and animals respore and produce methane, Ploughing can also increase CO2 stored in soil and machinery as fuel. Monoculture farming lowers biodiversity. Agriculture emits more CO2 than transport globally. - Urbanisation- Urban areas account for 97% of all anthropogenic carbon dioxide emissions, contributes include transport, industry and cement making Changes to the magnitude of carbon stores over time are called fluxes and may happen rapidly or over thousands of years. However human activity is causing an unprecedented flux in the levels:

Question 50

What is carbon capture and storage

Answer 50

Carbon Dioxide is is captured and transported via a pipeline to underground or ocean stores. Once in ocean it will sink and remain there for many years until entering the geological cycle

Question 51

Talk about wetland restoration as a carbon capture and storage

Answer 51

Rehabilitation of degraded wetland so that soils, vegetation and habitat are a close approximation of the origional natural condition. Wetland restoration provides habitats and controls erosion and flooding. Restoring mangroves, salt marshes and seagrasses reduces greenhouse gas emissions and enhances biodiversity.

Question 52

Talk about the carbon cycles impacts on climate change

Answer 52

During the Quaternary, climates oscillated between glacial and interglacial periods—patterns reflected in ice core CO₂ records. Higher CO₂ levels enhance the greenhouse effect, raising temperatures and triggering permafrost melt, increased plant growth, droughts, reduced albedo, and more wildfires, which in turn influence CO₂ levels. Conversely, glacial periods lock CO₂ in ice, and reduced photosynthesis and decomposition lower atmospheric CO₂, weakening the greenhouse effect.

Question 53

Talk about the impact of the carbon cycle on land

Answer 53

- Formation and development of soil in the form of organic matter, introduces important nutrients and provides structure. It also is essential for plant growth. - Source of energy in the form of wood and fossil fuels