WATER AND CARBON CYCLE 20 MARKERS
Outline the process of photosynthesis in the carbon cycle [4 marks]
Photosynthesis is a fundamental part of the carbon cycle. Carbon dioxide is taken in from
the atmosphere by plants, which reacts with the chlorophyll in the leaves and creates
glucose. The glucose is then used for plant growth. Plant growth acts as a carbon sink, as it
takes carbon out of the atmosphere. Oxygen is released as a by-product of photosynthesis,
which maintains the balance between carbon and oxygen in the atmosphere.
Outline the process of decomposition in the carbon cycle [4 marks]
Decomposition refers to the breakdown of organic matter by bacteria or fungi, which are
collectively known as decomposers. During decomposition, carbon dioxide is released,
mainly into the atmosphere. Decomposition is heavily temperature dependent, as warmer
temperatures are characterised by much higher rates of decomposition a there is more
microbial activity. However, the presence of water is also a key feature in the rate of
decomposition and the release of carbon.
Explain the concept of dynamic equilibrium in relation to the carbon cycle [4 marks]
Dynamic equilibrium refers to the tendency towards a natural state of balance within the
carbon cycle. The carbon cycle is a closed system, as no carbon enters or leaves the
system, it is simply recycled around the system. However, dynamic equilibrium is often upset
by events such as wildfires, or human activity including deforestation. This causes
interference in the carbon cycle which is evidenced through global warming.
How far do you agree that changes to the carbon cycle will lead to increasingly severe storm
events? [9 marks]
Storms begin in an area of low pressure from surface heating. Changes to the carbon cycle,
particularly due to human activity, will lead to increasingly severe storm events to a certain
extent.
As populations have grown significantly over time, the combustion of fossil fuels and
deforestation has increased. This means that more carbon dioxide is being released into the
atmosphere and there are less trees photosynthesising, acting as a carbon sink and
sequestering carbon into the biosphere. Increased levels of carbon dioxide in the
atmosphere have led to a more pronounced greenhouse effect over the world. This has
increased temperatures around the globe, therefore causing greater levels of
evapotranspiration. This means that there is an increased level of moisture in the air
providing latent heat. Rising it causes moisture to be released by condensation, so the
continuation of this process is what drives storms. Storms are typically found in areas such
as Southeast Asia and west of central America, due to their warmer climates, close to the
equator. As temperatures increase across the world from changes to the carbon cycle, it is
likely that there will be an increase in storm intensity further from the equator. For example,
by 2100 there is predicted to be up to an 11% increase in average intensity of storms.
On the other hand, higher temperatures as a result of human activity will also cause an
increase in evaporation on land. This increase in aridity is often linked to an increase in
wildfires, which creates a positive feedback loop as less plants are sequestering carbon and
atmospheric temperatures therefore increase. This reduces water in the hydrosphere, which
can lead to an increase in desertification which affects areas around the world that are
already arid. This means that there is less moisture content in the atmosphere available to
fuel the storms, which means that there would not be an increase in severity of storm events
over time, despite the warmer climates. Therefore, changes to the carbon cycle are linked
with the spread of aridity, rather than an increase in severity of storm events.
, WATER AND CARBON CYCLE 20 MARKERS
In conclusion, I agree that changes to the carbon cycle will lead to increased severity of
storm events. Human activity is particularly responsible for these changes as the magnitude
of atmospheric carbon increases. However, increased global temperatures is also linked to
the spread of aridity, therefore this conclusion is partial.
Assess the impact of farming practices on the carbon budget. [9 marks]
Farming practices, including for cattle and for crops, are having impacts on the carbon
budget to a certain extent. As populations are increasing over time and demand for
resources are as well, these impacts on the carbon budget are becoming more marked.
The Amazon rainforest stores up to a fifth of the carbon in the planet’s biomass, therefore
deforestation of the rainforest has had significant impacts on the carbon budget. 80% of
deforestation in the Amazon is a result of cattle ranching. As a result, much of the carbon
that was being sequestered in the biosphere has now been released into the atmosphere.
This land is then replaced by cattle farms, which means there are no longer trees
sequestering carbon, and the rainforest becomes a carbon source. These changes to the
carbon budget increase global temperatures as extra carbon in the atmosphere contributes
to the greenhouse gas effect. Therefore, destruction of the rainforest for cattle ranching is
having detrimental impacts for the carbon budget and causing significant changes for the
climate.
Farming practices contribute to 10% of global carbon emissions, particularly as a result of
crop farming. When soil is ploughed, the layers invert which causes air to mix into the soil
and decomposition to increase. This means that more soil organic matter is being
decomposed so more CO2 is being released into the atmosphere. Crop farming also
requires land, therefore it is common for areas of land to be deforested and replaced with
farmland. Although the crops replacing the trees have the potential to sequester large
amounts of carbon, they cannot store as much in comparison to woodland as they are much
smaller. Therefore, farming for crops also contributes significantly to the changes in the
carbon budget.
In conclusion, farming practices are having a significant impact on the carbon budget, as
cattle ranching and crop farming contribute to an increase in CO2 in the atmosphere.
However, crop farming may contribute less in comparison to cattle ranching, as crops are
still able to store some carbon in the biosphere.
The changes in the carbon cycle are more marked (significant) on land than in either the
oceans or atmosphere. Discuss [20 marks]
The carbon cycle is a cycle in which carbon is transferred between different stores on Earth
by different processes, such as photosynthesis and decomposition. Carbon dioxide levels in
the carbon cycle have seen major changes over time, and are currently the highest they
have been in human history. This has had significant impacts on land, oceans and the
atmosphere, as high carbon levels are associated with devastating consequences, such as
global warming.
On the one hand, land has been and is currently being impacted significantly by rises in
levels of carbon dioxide. Anthropogenic activities, such as land use changes, have resulted
in a shift in the size of carbon stores, as carbon moves from the biosphere to the
atmosphere. As populations have increased over time, there is a higher demand for food
and resources, therefore there has been an increase in deforestation for farmland. Farming
practices are responsible for 10% of the global carbon releases, which is linked to the
warming of our climate over time due to the enhanced greenhouse effect. This is because
forests typically act as larger carbon sinks than crops on agricultural land. When trees are
Outline the process of photosynthesis in the carbon cycle [4 marks]
Photosynthesis is a fundamental part of the carbon cycle. Carbon dioxide is taken in from
the atmosphere by plants, which reacts with the chlorophyll in the leaves and creates
glucose. The glucose is then used for plant growth. Plant growth acts as a carbon sink, as it
takes carbon out of the atmosphere. Oxygen is released as a by-product of photosynthesis,
which maintains the balance between carbon and oxygen in the atmosphere.
Outline the process of decomposition in the carbon cycle [4 marks]
Decomposition refers to the breakdown of organic matter by bacteria or fungi, which are
collectively known as decomposers. During decomposition, carbon dioxide is released,
mainly into the atmosphere. Decomposition is heavily temperature dependent, as warmer
temperatures are characterised by much higher rates of decomposition a there is more
microbial activity. However, the presence of water is also a key feature in the rate of
decomposition and the release of carbon.
Explain the concept of dynamic equilibrium in relation to the carbon cycle [4 marks]
Dynamic equilibrium refers to the tendency towards a natural state of balance within the
carbon cycle. The carbon cycle is a closed system, as no carbon enters or leaves the
system, it is simply recycled around the system. However, dynamic equilibrium is often upset
by events such as wildfires, or human activity including deforestation. This causes
interference in the carbon cycle which is evidenced through global warming.
How far do you agree that changes to the carbon cycle will lead to increasingly severe storm
events? [9 marks]
Storms begin in an area of low pressure from surface heating. Changes to the carbon cycle,
particularly due to human activity, will lead to increasingly severe storm events to a certain
extent.
As populations have grown significantly over time, the combustion of fossil fuels and
deforestation has increased. This means that more carbon dioxide is being released into the
atmosphere and there are less trees photosynthesising, acting as a carbon sink and
sequestering carbon into the biosphere. Increased levels of carbon dioxide in the
atmosphere have led to a more pronounced greenhouse effect over the world. This has
increased temperatures around the globe, therefore causing greater levels of
evapotranspiration. This means that there is an increased level of moisture in the air
providing latent heat. Rising it causes moisture to be released by condensation, so the
continuation of this process is what drives storms. Storms are typically found in areas such
as Southeast Asia and west of central America, due to their warmer climates, close to the
equator. As temperatures increase across the world from changes to the carbon cycle, it is
likely that there will be an increase in storm intensity further from the equator. For example,
by 2100 there is predicted to be up to an 11% increase in average intensity of storms.
On the other hand, higher temperatures as a result of human activity will also cause an
increase in evaporation on land. This increase in aridity is often linked to an increase in
wildfires, which creates a positive feedback loop as less plants are sequestering carbon and
atmospheric temperatures therefore increase. This reduces water in the hydrosphere, which
can lead to an increase in desertification which affects areas around the world that are
already arid. This means that there is less moisture content in the atmosphere available to
fuel the storms, which means that there would not be an increase in severity of storm events
over time, despite the warmer climates. Therefore, changes to the carbon cycle are linked
with the spread of aridity, rather than an increase in severity of storm events.
, WATER AND CARBON CYCLE 20 MARKERS
In conclusion, I agree that changes to the carbon cycle will lead to increased severity of
storm events. Human activity is particularly responsible for these changes as the magnitude
of atmospheric carbon increases. However, increased global temperatures is also linked to
the spread of aridity, therefore this conclusion is partial.
Assess the impact of farming practices on the carbon budget. [9 marks]
Farming practices, including for cattle and for crops, are having impacts on the carbon
budget to a certain extent. As populations are increasing over time and demand for
resources are as well, these impacts on the carbon budget are becoming more marked.
The Amazon rainforest stores up to a fifth of the carbon in the planet’s biomass, therefore
deforestation of the rainforest has had significant impacts on the carbon budget. 80% of
deforestation in the Amazon is a result of cattle ranching. As a result, much of the carbon
that was being sequestered in the biosphere has now been released into the atmosphere.
This land is then replaced by cattle farms, which means there are no longer trees
sequestering carbon, and the rainforest becomes a carbon source. These changes to the
carbon budget increase global temperatures as extra carbon in the atmosphere contributes
to the greenhouse gas effect. Therefore, destruction of the rainforest for cattle ranching is
having detrimental impacts for the carbon budget and causing significant changes for the
climate.
Farming practices contribute to 10% of global carbon emissions, particularly as a result of
crop farming. When soil is ploughed, the layers invert which causes air to mix into the soil
and decomposition to increase. This means that more soil organic matter is being
decomposed so more CO2 is being released into the atmosphere. Crop farming also
requires land, therefore it is common for areas of land to be deforested and replaced with
farmland. Although the crops replacing the trees have the potential to sequester large
amounts of carbon, they cannot store as much in comparison to woodland as they are much
smaller. Therefore, farming for crops also contributes significantly to the changes in the
carbon budget.
In conclusion, farming practices are having a significant impact on the carbon budget, as
cattle ranching and crop farming contribute to an increase in CO2 in the atmosphere.
However, crop farming may contribute less in comparison to cattle ranching, as crops are
still able to store some carbon in the biosphere.
The changes in the carbon cycle are more marked (significant) on land than in either the
oceans or atmosphere. Discuss [20 marks]
The carbon cycle is a cycle in which carbon is transferred between different stores on Earth
by different processes, such as photosynthesis and decomposition. Carbon dioxide levels in
the carbon cycle have seen major changes over time, and are currently the highest they
have been in human history. This has had significant impacts on land, oceans and the
atmosphere, as high carbon levels are associated with devastating consequences, such as
global warming.
On the one hand, land has been and is currently being impacted significantly by rises in
levels of carbon dioxide. Anthropogenic activities, such as land use changes, have resulted
in a shift in the size of carbon stores, as carbon moves from the biosphere to the
atmosphere. As populations have increased over time, there is a higher demand for food
and resources, therefore there has been an increase in deforestation for farmland. Farming
practices are responsible for 10% of the global carbon releases, which is linked to the
warming of our climate over time due to the enhanced greenhouse effect. This is because
forests typically act as larger carbon sinks than crops on agricultural land. When trees are
