water and carbon cycles aqa a level geography paper 1

Explain the 'system concept' relating to the water cycle

The water cycle can be views as a system made from inputs, outputs, stores and flows

Main input is precipitation and outputs are evapotranspiration and runoff.

Water stored in places such as atmosphere, rivers and groundwater

Flows such as infiltration, percolation move water between stores.

Closed system on global scales so not water is lost or added

Explain the 'system concept' relating to the carbon cycle

The carbon cycle is a system made of inputs, outputs, stores and flows

Carbon enters atmosphere through outputs e.g. respiration and combustion.

Stored in the atmosphere, lithosphere, hydrosphere and biosphere

Photosynthesis and decomposition are flows and move carbon between stores

Closed system on global scale- not lost or gained overall

Outline the inputs, outputs and stores in the water cycle

Main input = precipitation

Outputs = evapotranspiration and river discharge into oceans

Stores= lithosphere, cryosphere, hydrosphere and atmosphere

Move through stores with flows e.g. infiltration, percolation and surface runoff

Explain the inputs, stores and outputs of the carbon cycle

Inputs to the carbon cycle = respiration, combustion and volcanic eruptions → release carbon into the atmosphere

Main stores = atmosphere, oceans, biosphere and lithosphere

Outputs = photosynthesis or carbon sequestration in oceans and sediments

Explain 'positive feedback' in relation to the water cycle

Positive feedback is when the effects caused are amplified an example in the water cycle is global warming. This leads to more evaporation, increasing atmospheric water vapour. This water vapour is a greenhouse gas, enhancing the greenhouse effect, causing more warming and evaporation

Outline 'negative feedback' in relation to the water cycle

Negative feedback in the water cycle is when the change is nullified and helps return the cycle back to its equilibrium state. An example could be an increase in evapotranspiration due to higher temps leading to cloud formation. This reduces solar radiation, lowering the global temps reducing evaporation

Outline 'positive feedback' in relation to the carbon cycle

Positive feedback is when the effects caused are amplified an example in the carbon cycle is rising global temperatures. This can cause permafrost to melt, releasing stored CO2 and methane. These greenhouse gases enhance the greenhouse effect → further warming and more permafrost melt

Explain 'negative feedback' in relation to the carbon cycle

Negative feedback in the water cycle is when the change is nullified and helps return the cycle back to its equilibrium state. An example in the carbon cycle is afforestation. This can lead to carbon dioxide increasing leading to an increase in photosynthesis. As plants absorb more CO2, atmospheric levels of CO2 decrease, returning the carbon cycle back to its equilibrium state.

Explain the term 'dynamic equilibrium' in the water cycle

Dynamic equilibrium in the water cycle refers to a balanced state where the inputs, outputs and stores remain relatively constant over time. Although water moves through each process, the overall amount in each store stays stable unless disrupted by external factors such as climate change or human activity

Outline the term 'dynamic equilibrium' in the carbon cycle

Dynamic equilibrium in the carbon cycle refers to a balanced state where the amount of carbon moving between stores remains relatively stable over time. Although carbon moves through each process like photosynthesis and respiration, the total amount in each store stays constant unless disrupted by human activity or natural events

Explain what is meant by stores in relation to the water cycle

Stores refer to where water is held for periods of time. Includes atmosphere ( as vapour), oceans, rivers, lakes, groundwater and glaciers. Water is stored before moving to other parts of the cycle through processes such as evaporation, precipitation and runoff

Explain what is meant by stores in relation to the carbon cycle

Stores refer to where carbon is held for varying periods of time. Includes atmosphere (as CO2), oceans (dissolved) lithosphere (fossil fuels and sedimentary rocks) biosphere (living organisms and soil). Carbon moves between these stores through processes such as photosynthesis, respiration and combustion.

Outline what is meant by inputs in relation to the water cycle

Inputs refers to the addition of water into the system. Main input is precipitation, including rain, snow, sleet and hail. Other inputs can include water melting from snow and ice or water from human activities such as irrigation

Explain what is meant by inputs in relation to the carbon cycle

Inputs refer to the addition of carbon into the system. Key inputs = CO2 in atmosphere through respiration, combustion and volcanic eruptions. Additionally, carbon is also absorbed by plants during photosynthesis and can be transferred from the atmosphere to the oceans through diffusion

Explain what is meant by outputs in relation to the water cycle

Outputs refer to the removal of water from the system. Main outputs = evapotranspiration→ combined process of evaporation from surfaces and transpiration from plants and runoff where water flows from land into rivers, lakes and oceans. These outputs help balance the water stored in various stores within the cycle

Outline what is meant by outputs in relation to the carbon cycle

Outputs refer to the processes that release carbon from the system. Main outputs = CO2 into atmosphere through respiration, combustion, volcanic activity. Additionally, carbon can be lost from the biosphere to oceans through diffusion and from land to atmosphere through decomposition

Explain what is meant by the term flows in relation to the water cycle

In the water cycle, 'flows' refer to the processes that transfer water between different stores. These are the movements of water, driven by gravity and energy from the sun. For example, infiltration is a flow where water moves from the surface into the soil, while percolation is the flow of water from the soil into permeable rock. Another key flow is surface runoff, where water moves across the land, often into rivers. Additionally, flows like throughflow involve the lateral movement of water within the soil layer, and groundwater flow describes the slow movement of water through rock formations.

Outline what is meant by the term flows in relation to the carbon cycle

Flows, in the context of the carbon cycle, refer to the movement of carbon between different stores. These stores include the atmosphere, oceans, biosphere, and lithosphere. These movements, also known as fluxes or transfers, occur through various processes. Photosynthesis, for instance, is a flow where carbon moves from the atmosphere into the biosphere as plants absorb CO2. In contrast, respiration is a flow where carbon moves from the biosphere back to the atmosphere.

Explain the global distribution of the major stores of water

The global distribution of water is uneven, with the majority stored in the hydrosphere, particularly the oceans. Oceans cover approximately 71% of the Earth's surface and hold about 97% of all water. The cryosphere, which includes ice caps, glaciers, and permafrost, contains a significant portion of freshwater, with large stores concentrated in polar regions like Antarctica and Greenland. Freshwater in the lithosphere (as groundwater) is also unevenly distributed, depending on geological factors like rock permeability and porosity, with some regions having large aquifers while others have limited groundwater storage.

Outline the size of the major stores of water

The hydrosphere is the largest store, holding approximately 96.5% of all Earth's water, with the vast majority in the oceans. This represents the immense scale of this store compared to others. The cryosphere, including ice caps and glaciers, accounts for around 1.7% of Earth's water, making it the largest store of freshwater, even though it's much smaller than the hydrosphere overall. The lithosphere (as groundwater) holds a significant, but smaller, portion of freshwater, estimated at about 1.6% of the total global water, highlighting the substantial amount stored underground. The atmosphere holds the smallest amount of 8% of freshwater available.

Explain the global distribution and size of the lithosphere as a major store of water

The lithosphere stores water primarily as groundwater, which is distributed globally but unevenly. Its presence is highly dependent on geology with porous and permeable rocks holding more water. The lithosphere holds a significant portion of the earth's fresh water. However, compared to the total global water store, it's a smaller percentage than the hydrosphere.

Explain the global distribution and size of the hydrosphere as a major store of water

The hydrosphere encompasses all of Earth's liquid water and its distribution is heavily concentrated in the oceans. Oceans cover approx 71% of the earth's surface, resulting in marine distribution. The hydrosphere is the largest water store containing 97% of the water on earth. This shows the large scale of this store

Explain the global distribution and size of the cryosphere as a major store of water

The cryosphere consists of frozen water and is concentrated in the polar regions. Major stores are in Antarctica as ice sheets. This also includes glaciers and permafrost. The cryosphere holds a significant proportion of of the earth's fresh water at 79% of freshwater. It is the 2nd largest store of water after oceans but the largest store of freshwater

Explain the global distribution and size of the atmosphere as a major store of water

The atmosphere's water content, primarily in the form of water vapour is distributed globally, but varies with temperature. Warmer equatorial regions hold more atmospheric water due to high evaporation rates whilst colder polar regions hold less. The atmosphere is the smallest of major water stores holding 8% of the 1% accessible freshwater. However, despite being a small portion, it is significant in the water cycle as it moves water around the planet through precipitation.

Outline the processes driving change in the magnitude of the lithosphere

Magnitude of water stored in the lithosphere, primarily groundwater is influenced by several key flows: infiltration of precipitation through the soil and permeable rocks increases the amount of water stored. However, groundwater flow can decrease storage as water moves to rives, lakes and oceans. Human activities also play a significant role such as abstraction as this reduces the volume of groundwater and land use changes like urbanisation which increases impermeable surfaces reducing drainage alters the amount of water reaching and stored in the lithosphere

Outline the processes driving change in the magnitude of the hydrosphere

The magnitude of the hydrosphere is primarily driven by balance between inputs and outputs. Precipitation increases the volume of water in the hydrosphere whereas evaporation decreases the hydrospheres volume and increases the atmospheric volume of water. Other factors such as melted ice from the cryosphere adds to the hydrosphere and human activities like dams alter the distribution and flow of water.

Outline the processes driving change in the magnitude of the cryosphere

The magnitude of the cryosphere changes due to changes in inputs and outputs. Inputs are snowfall, increasing the cryosphere's magnitude whereas outputs is snow or ice melt. This reduces the cryosphere's magnitude. Global warming significantly decreases the magnitude of the cryosphere as it melts the glaciers and ice

Outline the processes driving change in the magnitude of the atmosphere

The magnitude of atmospheric water changes due to evaporation from oceans, lakes, rivers and soils. This increases atmospheric water. This is driven by increased solar energy and temperature. However, condensation decreases the amount of water vapour therefore decreasing atmosphere water magnitude. When the vapour grows large enough, precipitation occurs removing water from the atmosphere as rain, snow or hail.

Explain the process of evaporation in the water cycle system

Evaporation is the process by which liquid water changes into a gas, water vapour and moves from the hydrosphere to the atmosphere. This requires energy, usually solar radiation which heats the water breaking the bonds holding the molecules together. The rate is influenced by temperatures, surface area, low humidity and wind speed. This is a critical component of the water cycle, influencing global and local climates

Explain the process of cloud formation in the water cycle system

Cloud formation occurs when water vapour in the atmosphere cools and condenses changing state from a gas to a liquid or solid. This happens as air rises, expands and its temperature decreases. Condensation is tiny particles providing surfaces for water vapour to adhere to. As more water condenses, the droplets saturate the air, grow together forming clouds.

Outline the cause of precipitation in the water cycle system

Precipitation is the release of water from the atmosphere due to water droplets forming clouds that become too heavy to be suspended. Precipitation can be rain, snow or hail. There are 3 types of rainfall: conventional, relief, frontal. Conventional rainfall is due to heating of the sun, warm air rises and condenses at high altitudes, changing state and falling as rain
Relief rainfall is when warm air is forced upward by a barrier such as mountains, causing it to condense at high altitudes and fall as rainfall. Frontal rainfall is when warm air rises over the cool air. Because the warm air is less dense and lighter, it condenses at higher altitudes and falls as rainfall.

Explain the role of cryospheric in the water cycle system

The cryosphere encompasses all frozen water on earth. This acts like a reservoir holding water in ice sheets, glaciers and permafrost.

Outline the role of cryospheric processes at hill slope in the water cycle

Cryospheric processes significantly influence water movement on a hill slope. Snow accumulation act as a temporary store, holding water that would otherwise flow quickly downslope. During snowmelt, water is released gradually increasing through flow and infiltration into the soil, thus recharging groundwater stores. In areas with frozen ground or permafrost, infiltration is reduced leading to increased surface runoff and soil saturation

Explain the role of cryospheric processes at the drainage basin in the water cycle

There are two main cryospheric processes: accumulation and ablation. Accumulation refers to the upper part of the glacier when inputs exceed outputs so more mass is gained than lost. Ablation is when the outputs exceed inputs so more mass is lost than gained. This changes the amount of water in the cryosphere, hydrosphere and atmosphere.

Outline the role of cryospheric processes at global scales in the water cycle

The cryosphere contains ice sheets, glaciers and permafrost. It is a major store of the earths freshwater and significantly affects the global water cycle by storing water as ice and releasing it when it melts. When stored, ice sheets reduce the sea levels as all the particles are concentrated. When they melt, water is a liquid and therefore takes up more space, this increases the sea levels. Snow and ice also reflect sunlight, this influences global temps and therefore affects evapotranspiration and precipitation.

Outline the inputs in the drainage basin open system

The drainage basin is an open system. Water enters its boundaries through precipitation. This includes rain, snow, sleet and hail. Amount and type of precipitation at the drainage basin is affected by climate, location and weather patterns. For example, in the river itchen, rainfall is the input of precipitation due to the mild maritime climate.

Outline the outputs in the drainage basin open system

A drainage basin is an open system. Water is lost through several outputs. The most significant is river discharge. This is the total volume of water flowing out of the basin through the main river channel and it tributaries. Another important output is evapotranspiration which is the combined loss of water to the atmosphere through evaporation from water bodies and the ground surface and transpiration from plants. A further output is groundwater flow which is when water slowly moves out of the basin through permeable rocks and aquifers. Water can also be removed from the drainage basin through abstraction.

Explain role precipitation in the drainage basin

Precipitation is the primary input of water into a drainage basin. It directly influence the magnitude of all other components within the system such as runoff, infiltration and groundwater recharge. High precipitation levels can lead to increased river discharge and a greater risk of flooding, however, low precipitation levels can lead to drought conditions. Precipitation can affect vegetation growth and soil moisture impacting evapotranspiration rates and the water balance within the drainage basin.

Explain the role of evapotranspiration in the drainage basin

Evapotranspiration is a critical process in a drainage basin as it represents the loss of water by evaporation and transpiration. High rates of evapotranspiration reduce the amount of water available for runoff and groundwater recharge equalling lower river discharge. This is influenced by temperature, vegetation and humidity. Seasonally, evapotranspiration rates vary, affecting soil moisture levels, influencing timing and magnitude of river flow with higher rates occurring in warmer months

Outline the role of runoff in the drainage basin system

Runoff is the movement of water across a land surface. It occurs when precipitation exceeds the infiltration capacity and transfers water to river channels. The volume and rate is influenced by peak discharge of a river, affecting the likelihood of flooding. Additionally, runoff transports sediments across the landscape and can impact the quality of water within the drainage basin

Explain stores and flows in the drainage basin open system

A drainage basin contains stores where water is held. Between stores are flows which is how water moves. Stores examples are … flow examples are through flow and infiltration. Stores and flows are interconnected and the change between stores depends on the balance of the flows

Outline the role of interception in the drainage basin

Interception is where vegetation captures precipitation before it reaches the soil and ground. This influences the timings in the drainage basin system and the amount of water reaching the surface. A larger interception rate decreases runoff, reducing the risk of flooding.

Explain the role of groundwater storage in the drainage basin

Groundwater storage is a significant store of water in the drainage basin system. It regulates river flow and provides steady supply of baseflow, sustaining river levels. Groundwater store is replenished by infiltration and percolation, contributing to overall water balance within the drainage basin.

Outline role channel storage in the drainage basin

Channel storage is the volume of water held in river channels. It temporarily holds water as it moves through the river drainage basin and smooths out variations in discharge caused by rainfall events. During storm events, it can help to reduce the risk of flooding by containing excess water.

Explain the role stemflow in the drainage basin

Stem flow is the process where intercepted water runs down tree trunks and steams of plants. Stem flow directs water to the base of the vegetation, concentrating the input of water to specific locations. This can increase infiltration locally, enhancing soil moisture levels around the plants. By concentrating water, groundwater recharge can also occur.

Outline the role of infiltration in the drainage basin

Infiltration si the process by which water on the ground surface enters the soil. It controls the amount of water that becomes surface runoff. High infiltration rate reduces runoff and the risk of flooding. Replenishes soil moisture, recharging groundwater. It is affected by soil type, vegetation cover, and saturation levels

Outline the role of channel flow in the drainage basin

Channel flow is the movement of water within a river channel. The volume and speed of the channel varies depending on precipitation, runoff and inputs. Can lead to flooding if channel capacity is exceeded. Efficiency is influenced by channel gradient, shape and roughness

Explain the concept of the water balance

The water balance is the balance between inputs and outputs in a drainage basin.

Explain the term 'runoff variation' in the water cycle

Runoff is the movement of water across a land surface. This varies over different timescales. short term variations are seen during and immediately after rainfall events, where runoff increases rapidly, potentially leading to flooding. Long term variations can occur seasonally with higher runoff in wetter seasons and less in drier seasons. Precipitation intensity, soil type, vegetation cover and human activities contribute to these fluctuations.

Outline the term 'flood hydrograph' in the water cycle

A flood hydrograph is a graph showing the discharge of a river over a period of time where the normal flow of a river is affected by a storm event. The graph plots the discharge against time. The shape of a flood hydrograph is influenced by various drainage basin characteristics such as size, shape, geology, soil type and land use. This affects how quickly water reaches the river channel.

Outline changes in the water cycle over time

Over time changes in the water cycle can occur from storm events. This can increase precipitation and cause rapid increases in surface run off and river discharge, leaving the stores and flows unbalanced. Another change in the water cycle is seasonality, this affects evapotranspiration rates, precipitation which impacts the river discharge and groundwater recharge. A further change in the water cycle is farming practices. This is because practices such as irrigation which can divert water from rivers and deforestation which can reduce interception, increasing surface runoff.

Explain the term 'natural variation' in the water cycle

Natural variation refers to the fluctuations in the movement of storage of water due to natural processes. These processes can be storm events or seasonal changes. Storm events cause an increase in rainfall, which leads to increased runoff, river discharge and potential flooding. Seasonal changes are more predictable variations in precipitation, temperature and evapotranspiration, such as more evapotranspiration and less precipitation in the summer or monsoon seasons where it rains continuously for months.

Outline changes in the water cycle due to storm events

When storm events occur, they often increase the intensity of rainfall. This means that there is an increase in inputs into the water cycle. This leads to saturated ground and means that there is an increase in runoff. Furthermore, increased precipitation leads to increased river discharge. This combined with increased runoff can lead to floods.

Explain changes in the water cycle due to seasonal changes

Seasonal changes affect the water cycle due to varying inputs and outputs. In winter months, less evapotranspiration will occur due to lower temperatures and limited solar radiation. more precipitation will enter the water cycle. In the summer months, more evapotranspiration will occur and solar radiation will burn the clouds removing the water vapour from the atmosphere meaning that very little precipitation occurs.

Outline changes in the water cycle due to farming practices

Change in farming practices such as ploughing perpendicular to channels means that more infiltration occurs and less runoff occurs. Additionally, irrigation systems, increase the infiltration and transpiration rate of water as when it is sprayed the plants intercept and absorb it.

Explain changes in the water cycle due to land use change

When land use changes to be urbanised, the water cycle changes due to the ground becoming more impermeable. This reduces the infiltration that can occur and

Outline changes in the water cycle due to water abstraction

Water abstraction significantly alters the water cycle. A key change is the reduction in surface water stores. For example, abstraction for irrigation directly lowers river and lake levels. Additionally, groundwater abstraction impacts subsurface stores, leading to a decline in the water table. This can reduce baseflow, which is the contribution of groundwater to river discharge, causing some rivers to have reduced flow or even dry up. Finally, in coastal regions, excessive abstraction can cause saltwater intrusion into freshwater aquifers, contaminating them and disrupting the balance between freshwater and saltwater within the cycle.

Explain the hydrosphere as a major store of carbon

The hydrosphere is a major carbon store, primarily due to the oceans. Oceans dissolve CO2 directly from the atmosphere. This is enhanced in colder waters, driving a physical pump where cold, carbon rich water sinks. Marine organisms play a key role. Phytoplankton absorb CO2 for photosynthesis, transferring carbon through the food web. Dead organisms sink, storing carbon in sediments, potentially forming limestone.

Outline the cryosphere as a major store of carbon

The cryosphere, compromising earth's frozen water is a significant carbon store. A key component is permafrost which contains a vast amount of organic carbon. This carbon is from dead plant and animal matter that has been frozen and prevented from fully decomposing. As a result, carbon accumulates over thousands of years forming a store.

Explain the lithosphere as a major store of carbon

The lithosphere is a very large carbon store. Most of this carbon is found in rocks. Sedimentary rocks like limestone store carbon from shells and skeletons of marine organisms. Carbon is also stored in fossil fuels like coal, oil and gas

Outline the atmosphere as a major store of carbon

The atmosphere is a significant store of carbon holding CO2 and CH4. It holds about 800gt of carbon playing a key role in the carbon cycle. Carbon enters the atmosphere through processes like respiration, combustion and volcanic activity. It is removed through photosynthesis and absorption by oceans. It is important as it affects earth's climate.

Explain how flows and transfers at plant scale change the magnitude of carbon stores

At a plant scale, carbon flows through processes like photosynthesis and respiration. During photosynthesis, plants absorb carbon dioxide from the atmosphere and store it as carbon in biomass. This increases the biomass carbon store. When plants respire, carbon is released back into the into that atmosphere reducing the store. If plants die or decompose, carbon is transferred to the soil, changing the magnitude of soil carbon stores. These flows cause constant changes in carbon storage at a small scale.

Outline how flows and transfers at sere scale change the magnitude of carbon stores

At sere scale, (ecological succession stage), flows and transfers like photosynthesis, respiration, decomposition and biomass accumulation affect carbon stores. As a sere develops, vegetation grows and photosynthesis increases, storing more carbon in plant biomass. Overtime, dead organic matter adds carbon to the soil through decomposition. These processes increase the magnitude of both biomass and soil carbon stores. In contrast, early stages of sere have smaller carbon stores due to limited vegetation.

Explain how flows and transfers at continental scale change the magnitude of carbon stores

At a continental scale, flows and transfers such as deforestation, fossil fuels combustion and land use change can significantly alter carbon stores. For example, large scale deforestation in South America reduces biomass carbon stores and increases atmospheric CO2. Similarly, industrial activities across continents release stored carbon from fossil fuels into the atmosphere. On the other hand, afforestation and carbon sequestration projects can increase land-based carbon stores. These large scale changes impact the balance of carbon between land, ocean and atmosphere.

Outline the concept of photosynthesis in the carbon cycle

Photosynthesis is a crucial part of the carbon cycle which facilitates the transfer of carbon from the atmosphere to the biosphere. Plants, algae and some bacteria use sunlight energy to convert carbon dioxide and water into glucose (simple sugar and oxygen). Photosynthesis happens when plants absorb CO2 from the atmosphere, acting as a carbon sink. This carbon is then stored as glucose, used for growth and respiration. The carbon can be stored for varying amounts of time. When trees and plants are cut down or die, their stored carbon is released back into atmosphere through decomposition. Photosynthesis regulates the concentration of CO2 in the atmosphere influencing the earth's climate

Explain the concept of respiration in the carbon cycle

Respiration is a key process in the carbon cycle. It involves the release of CO2 back into the atmosphere. It is the opposite of photosynthesis. Living organisms break down glucose and oxygen to obtain energy. Through this process, CO2 is produced as a waste product. this CO2 is then released back into the atmosphere. The rate of respiration can be influenced by factors like temperature, which is high can increase respiration rates

Outline the term concept of decomposition in the carbon cycle

Decomposition is when organisms die and bacteria or fungi break down their organic matter. This process releases carbon back into the atmosphere as CO2. The rate of decomposition can be affected by factors such as temperature and moisture. Decomposition tends to be faster in warmer and damper conditions and slower in colder and drier conditions

Explain the term combustion in the carbon cycle

Combustion is a chemical process of releasing carbon stored as CO2 into the atmosphere. This process requires oxygen and a fuel source. Commonly this is achieved by burning fossil fuels like coal, oil and natural gas. When these are burned large amounts of carbon stored is released into teh atmosphere. Combustion is a natural process but human activities have increased this rate primarily due to the burning of fossil fuels

Outline how carbon sequestration in the ocean changes the magnitude of stores in the carbon cycle

Carbon sequestration is the removal and storage of CO2 from the atmosphere to storage in the ocean. This decreases the magnitude of carbon stored in the atmosphere and increases the magnitude of carbon stored in the oceans. Oceans are a significant store of CO2 becuase they directly absorb it from the atmosphere. This increases the carbon stored in the hydrosphere. Additionally, some marine life such as phytoplankton use CO2 for photosynthesis adding it to their biomass and increasing the biospheric store of carbon in the oceans.

Explain how carbon sequestration in sediments changes the magnitude of stores in the carbon cycle

Carbon sequestration in sediments is a long term process that significantly alters the magnitude of carbon stores. It primarily involves the accumulation of carbon-rich organic matter, e.g. remains of dead marine organisms. Over time, this material is buried and compacted. This form as sedimentary rock like limestone. This process effectively transfers carbon from the active stores into long term stores within the lithosphere, dramatically increasing the magnitude of the lithospheric carbon store.

Outline how weathering changes the carbon cycle

Weathering is a group of processes that breaks down rocks. It plays a significant role in the carbon cycle . Chemical weathering removes CO2 from the atmosphere. An example could be atmospheric CO2 dissolving in rainwater forming acid rain. This reacts with rocks like limestone, dissolving the rock and releasing calcium ions and bicarbonate ions into rivers which eventually flow into the ocean. In the ocean, these ions can be used by marine organisms to form skeletons which eventually become part of sedimentary rocks, storing the carbon long term.

Outline combustion as a factor changing the carbon cycle

Combustion is a process that releases stored carbon into the atmosphere, significantly altering the carbon cycle. It involves the burning of organic materials in the presence of oxygen, producing CO2. Naturally, wildfires contribute to combustion, transferring carbon from the biosphere to the atmosphere. However, the largest impact on the carbon cycle comes from human activities like burning of fossil fuels, these release vast amounts of previously stored carbon at an unprecedented rate.

Explain how volcanic activity is a factor in changing the carbon cycle

Volcanic activity releases carbon stored in the earth's lithosphere into the atmosphere changing the carbon cycle. During eruptions, CO2 is released from the mantle. This transfers carbon from long term storage into the atmospheric store increasing it. Overall contribution is less than human emissions, large eruptions can cause significant short-term increases in the atmosphere

Explain the global size distribution of the carbon cycle

The global carbon cycle involves stores of vastly different sizes and uneven distributions. The largest store is the lithosphere. This contains carbon in rocks and fossil fuels. The oceans are the 2nd largest and have dissolved CO2 and marine organisms. In contrast, the atmosphere has a relatively small store. It contains carbon mainly as CO2 and CH4. The biosphere holds the least amount of carbon.

Explain hydrocarbon fuel extraction and burning as a factor in changing the carbon cycle

The extraction and burning of hydrocarbon fuels significantly alters the carbon cycle. These fuels formed over millions of years represent as vast store of carbon within the lithosphere. When these fuels are burned for energy, the stored carbon is rapidly released into the atmosphere. This transfers of carbon from long term geological store to the atmosphere is the primary driver of the increase in atmospheric CO2

Outline deforestation as a factor changing the carbon cycle

Deforestation is the clearing of forests. It changes the carbon cycle as carbon uptake is reduced and carbon emissions increase. Trees absorb CO2 from the atmosphere through photosynthesis and they act as carbon sinks. When forests are cleared, this carbon sink is dismissed and stored carbon is released often through burning which increases the amount of CO2 in the atmosphere. Deforestation also reduces biodiversity, altering water cycles, further impacting the carbon cycle.

Explain land use changes as a factor changing the carbon cycle

Changes in land use such as changing forests to agriculture or urban areas alters the carbon cycle. These changes often involve removing vegetation, which reduces photo synthesis. Additionally land use changes such as agriculture of cattle increase carbon released into the atmosphere through the emittance of methane. This changes the carbon cycle as more carbon is released than stored.

Outline farming practices as a factor in changing the carbon cycle

Farming practices can influence the carbon cycle in many ways. One way is through ploughing of land. This can release CO2 from soil organic matter , increasing atmospheric carbon. Another way farming can influence carbon cycles is through cattle. This is becuase cattle release CH4 (methane) this increase the carbon in the atmosphere.

Explain the role of positive feedback in the atmosphere of water and carbon

Positive feedback loops amplify changes in the atmosphere, driving it away from a state of equilibrium. An example in the atmosphere is the ice albedo effect. Rising temperatures, initiated by atmospheric CO2 causes ice to melt. Ice has a high albedo effect. This causes solar radiation to be reflected back into space when the ice melts, it exposes darker ocean water or land. This absorbs more solar radiation, increasing absorption, further warming the atmosphere leading to more ice melt. This loop amplifies to initial warming.

Outline the ways to mitigate the impact of climate change

Mitigating climate change involves reducing the sources or increasing the sinks of greenhouse gases. One key strategy is changing energy supplies from fossil fuels to renewable sources like solar, wind or hydroelectric. This reduces CO2 emissions from electricity generation, transportation and industry. Another approach is afforestation. This involves planting more trees, these absorb CO2 from the atmosphere through photosynthesis, and store it in their biomass. A further method to mitigate the impact of climate change is through international agreements such as the Paris agreement. This aims to coordinate global efforts to reduce emissions through nationally and internationally determined contributions.

Explain the concept of a carbon budget

A carbon budget is the balance between the inputs and outputs of carbon from a carbon reserve of system over a given period. This tracks the flow of carbon. Inputs are emissions from burning fossil fuels, volcanic eruptions, respiration. Outputs are photosynthesis, ocean sequestration, and burial of organic matter. Human activities have disrupted the global carbon budget, leading to a significant increase in atmospheric CO2. This concept is important in helping understand climate change as it helps quantify how much carbon can be emitted while still limiting global warming.

Outline the impact of the carbon cycle on land

The carbon cycle significantly influences various processes on land. Photosynthesis is a key part of the cycle. It drives plant growth, forming the base of terrestrial food webs and ecosystems. Changes in land use such as deforestation for agriculture/ urbanisation disrupts the carbon cycle, releasing stored carbon, reducing the capacity of land to act as a carbon sink. This increases atmospheric CO2 levels and climate change , affecting terrestrial ecosystems through changing temperatures and precipitation patterns which can cause issues such as wildfires furthering impacting the carbon cycle on land.

Explain the impact of the carbon cycle in the oceans

The ocean plays a crucial role in the carbon cycle, regulating global climate by absorbing CO2 from the atmosphere. CO2 from the atmosphere dissolves in the ocean. Phytoplankton use this dissolved CO2 for photosynthesis, reducing the atmospheric carbon levels. The carbon is also stored in deep ocean sediments for long periods of time, acting as a carbon sink. However, increased CO2 can lead to ocean acidification, harming marine life such as corals and shell fish.

Outline the impact of carbon cycle in the atmosphere

The carbon cycle controls the amount of CO2 in the atmosphere. CO2 is a greenhouse gas that helps trap heat and keep the earth warm. If too much CO2 builds up it can lead to global warming. Human activities like burning fossil fuels are increasing atmospheric CO2, disrupting the natural cycle.

Outline the impact the carbon cycle has on global climate

The carbon cycle regulated the levels of greenhouse gases like CO2 in the atmosphere. When more CO2 is released than absorbed, global temperatures rise. This can lead to climate change effects such as rising sea levels and extreme weather. Natural processes like photosynthesis and ocean absorption help balance the climate.

Explain the role of carbon stores in supporting life on earth

Carbon stores as forests and soils provide carbon for plants through photosynthesis. This supports food chains by producing oxygen and energy for animals and humans. Oceans store dissolved carbon which supports marine ecosystems. Long term stores like fossil fuels also releases energy when used by animals.

Outline the relationship between the carbon cycle and the atmosphere

The carbon cycle moves carbon between the atmosphere, land and oceans. Plants take in CO2 from the atmosphere for photosynthesis. Respiration and combustion return carbon to the atmosphere. This exchange helps regulate earth's temperature and climate

Explain the role of negative feedback in the atmosphere of water and carbon

Negative feedback helps balance the carbon and water cycles. For example, more CO2 can increase plant growth, which removes more CO2 through photosynthesis. Warmer temperatures may lead to more evaporation, increasing cloud cover, which can reflect sunlight and cool the earth. These processes help prevent drastic climate changes.

Outline the link between positive feedback in the carbon cycle and climate change

Increased temperatures can lead to more carbon being released from permafrost. This adds more CO2 to the atmosphere, causing further warming. The cycle of warming and release of carbon is an example of positive feedback

Explain the link between negative feedback in the carbon cycle and climate change

Higher CO2 levels can increase plant growth through enhanced photosynthesis. More plants absorb more carbon, reducing atmospheric CO2. This helps to cool the climate slightly, acting as negative feedback, reducing the effect of climate change

Explain the link between positive feedback in the water cycle and climate change

Warmer temperatures increase evaporation rates. This adds more water vapour to the atmosphere, which is a greenhouse gas. More water vapour traps more heat, causing more warming. This cycle continues creating positive feedback.

Outline the link between negative feedback in the water cycle and climate change

Higher temperatures increases evaporation rates, which can lead to more cloud formation. More clouds reflect sunlight back into space, which can reduce surface temperatures and slow warming.

Outline human interventions in the carbon cycle

Afforestation adds trees which absorb carbon through photosynthesis. Carbon capture and storage trap CO2 from power stations underground. Switching to renewable energy reduces emissions from fossil fuels. Sustainable farming can improve soil carbon storage

Outline the global distribution and size of the biosphere in the carbon cycle

The biosphere includes all living organisms and is found across continents and oceans. Tropical rainforests like the amazon, store large amounts of carbon in vegetation and soils. Grasslands and temperate forests also act as carbon stores. Oceans contain marine life which contributes to carbon storage in the biosphere.