Water and Carbon Cycles - Links and Feedback

Summary

This video explores the interconnections between the water and carbon cycles, emphasizing their fundamental roles in sustaining life on Earth. It discusses how these cycles are influenced by each other and by human activities, such as climate change and deforestation. The script also delves into feedback mechanisms, illustrating how positive feedback loops can amplify climate change impacts, while negative feedbacks can help restore balance. Examples include the melting of permafrost releasing greenhouse gases and increased cloud cover reflecting sunlight to cool the Earth.

Takeaways

• 🌎 Water and carbon are essential building blocks for life on Earth and are continuously cycled through Earth's systems.
• 🔁 Both cycles involve a closed system with limited and fixed amounts of water and carbon on the planet.
• 🏞️ The lithosphere, biosphere, atmosphere, hydrosphere, and cryosphere serve as shared stores for both water and carbon cycles.
• 🌡️ The water and carbon cycles experience temporal changes, such as seasonal variations, and are influenced by spatial variations like climate zones.
• 💧 Water is a critical component in carbon cycle processes like photosynthesis and respiration, indicating a direct influence of the water cycle on the carbon cycle.
• 🌡️ Increased water vapor, a greenhouse gas, affects the carbon cycle by contributing to climate change.
• 🌊 Changes in the carbon cycle, such as those caused by climate change, can impact water stores like ice caps and glaciers.
• 🌳 Human activities like climate change, deforestation, and agriculture significantly disrupt the natural cycles of water and carbon.
• ➡️ Positive feedback loops, such as melting permafrost releasing more greenhouse gases, amplify changes within the cycles, leading to more severe effects.
• 🔁 The loss of sea ice due to warming oceans reduces albedo, causing more sunlight to be absorbed and leading to further temperature rises, another positive feedback loop.
• 🌱 Negative feedbacks, like increased photosynthesis at warmer temperatures absorbing CO2, work to diminish changes and restore balance to the cycles.

Q & A

What are the fundamental similarities between the water and carbon cycles?

Both water and carbon are essential building blocks for life on Earth, and both elements are continuously cycled around the Earth in closed systems with limited and fixed amounts respectively.

What are the common stores shared by the water and carbon cycles?

The Earth's lithosphere, biosphere, atmosphere, hydrosphere, and cryosphere serve as common stores for both the water and carbon cycles.

How do changes in the water cycle affect the carbon cycle?

Water is an essential component in processes like photosynthesis and respiration, which are part of the carbon cycle. Additionally, water vapor is a greenhouse gas that can influence the carbon cycle by affecting atmospheric temperatures.

How can changes in the carbon cycle impact water stores and transfers?

Changes in the carbon cycle, such as increased greenhouse gases due to human activities, can lead to global warming, which in turn can affect water stores like ice caps and glaciers.

What human activities can disrupt the natural water and carbon cycles?

Human activities such as climate change, deforestation, and agriculture can have significant impacts on both the water and carbon cycles by altering their natural processes and balances.

What is the concept of positive feedback in the context of the water and carbon cycles?

Positive feedback is a process that amplifies changes within a system. For example, increased temperatures due to climate change can lead to the melting of permafrost, releasing more greenhouse gases and further increasing temperatures.

Can you provide an example of a positive feedback loop involving the water cycle?

Yes, as ocean temperatures rise, increased evaporation can lead to higher concentrations of water vapor, a greenhouse gas, which in turn can cause further warming and more evaporation.

How does the loss of sea ice contribute to positive feedback loops?

Sea ice has a high albedo, reflecting sunlight and helping to cool the Earth. As sea ice diminishes due to warming, less sunlight is reflected, leading to more absorption of heat and further temperature rise.

What is the role of wildfires in creating positive feedback loops related to the carbon cycle?

Wildfires, intensified by droughts caused by climate change, release carbon dioxide into the atmosphere, contributing to the greenhouse effect and further warming.

What is the concept of negative feedback in the context of the water and carbon cycles?

Negative feedback works to diminish changes within a system, leading to a return to equilibrium. For example, increased temperatures could stimulate more photosynthesis, which absorbs carbon dioxide and can lead to cooling.

How does increased evaporation contribute to negative feedback loops?

Increased evaporation can lead to more cloud cover, which reflects sunlight and can cause a cooling effect, counteracting the initial temperature increase.

Outlines

00:00

🌎 Water and Carbon Cycles: Essential Building Blocks

This paragraph introduces the fundamental importance of water and carbon cycles for life on Earth. Both elements are essential for life and are continuously cycled through Earth's systems in a closed loop. They share similar stores such as the lithosphere, biosphere, atmosphere, hydrosphere, and cryosphere. The cycles are subject to temporal and spatial changes, with variations influenced by factors like climate and human activities. The paragraph also discusses how water is a critical component in carbon cycle processes like photosynthesis and respiration, and how water vapor acts as a greenhouse gas, influencing the carbon cycle. Human activities such as climate change and deforestation can disrupt these cycles.

05:01

🔥 Positive Feedback Loops in Climate Change

The second paragraph delves into the concept of positive feedback within the carbon cycle, using the example of temperature rise due to climate change. It explains how this can lead to the melting of permafrost, releasing more greenhouse gases and further increasing temperatures. The paragraph also discusses how increased ocean temperatures can lead to higher evaporation rates, adding more water vapor—a greenhouse gas—to the atmosphere. It mentions other impacts such as the release of dissolved CO2 from oceans and the decrease in sea ice, which reduces albedo and leads to more sunlight absorption and temperature rise. The paragraph also touches on how temperature rise can lead to droughts and increase the frequency and intensity of wildfires, releasing more CO2 and creating additional positive feedback loops.

10:03

❄️ Negative Feedback and Dynamic Equilibrium

The final paragraph contrasts positive feedback with negative feedback, which works to diminish changes and restore balance. It uses the example of increased temperatures potentially leading to more photosynthesis, which would absorb CO2 and reduce greenhouse gases, thus cooling the planet. The paragraph also discusses how increased evaporation can lead to more cloud cover, which reflects sunlight and creates a cooling effect, counteracting the initial temperature increase. This illustrates the role of negative feedback in maintaining dynamic equilibrium between the water and carbon cycles.

Keywords

💡Water Cycle

The water cycle, also known as the hydrologic cycle, is the continuous movement of water on, above, and below the surface of the Earth. It includes processes like evaporation, condensation, precipitation, and runoff. In the video, the water cycle is discussed as a fundamental system that shares stores with the carbon cycle, such as the lithosphere, biosphere, atmosphere, and hydrosphere. The water cycle is essential for life on Earth and is influenced by and influences the carbon cycle, particularly through processes like photosynthesis and respiration.

💡Carbon Cycle

The carbon cycle is the biogeochemical process by which carbon is cycled through the Earth's biosphere, geosphere, hydrosphere, and atmosphere. Carbon is exchanged among these systems through processes like photosynthesis, respiration, and decomposition. The video emphasizes the carbon cycle's importance as a building block for life and its interconnection with the water cycle, especially in processes that require water for carbon transfers to occur.

💡Feedbacks

Feedbacks in the context of the video refer to the processes that can either amplify or diminish changes within a system. Positive feedbacks exacerbate changes, leading to a more severe outcome, while negative feedbacks counteract changes, leading to a stabilization or return to equilibrium. The video discusses various feedbacks related to the water and carbon cycles, such as the melting of permafrost and increased evaporation, which can influence climate change.

💡Greenhouse Gases

Greenhouse gases are gases in the Earth's atmosphere that trap heat by absorbing and emitting radiant energy within the thermal infrared range. This leads to the greenhouse effect. The video mentions water vapor as a greenhouse gas and discusses how its increased presence in the atmosphere can affect the carbon cycle. Other greenhouse gases like carbon dioxide and methane are also implicated in the feedback loops that drive climate change.

💡Permafrost

Permafrost is soil that remains frozen for at least two consecutive years, often containing large amounts of carbon in the form of organic matter. The video explains that the melting of permafrost due to temperature rise can release more greenhouse gases into the atmosphere, creating a positive feedback loop that contributes to global warming.

💡Albedo

Albedo refers to the measure of the reflectivity of a surface, which determines how much sunlight is reflected back into space. In the video, it is mentioned in the context of sea ice, which has a high albedo and reflects a significant amount of sunlight. The loss of sea ice due to warming temperatures reduces albedo, leading to more sunlight being absorbed and contributing to further warming.

💡Evaporation

Evaporation is the process by which water changes from a liquid to a gas or vapor. The video discusses how increased evaporation rates, due to warmer temperatures, can lead to higher levels of water vapor in the atmosphere, which is a greenhouse gas, thus contributing to the greenhouse effect and climate change.

💡Photosynthesis

Photosynthesis is the process by which green plants and some other organisms use sunlight to synthesize foods with carbon dioxide and water, releasing oxygen in the process. The video explains that photosynthesis requires water and is a crucial part of the carbon cycle. It also mentions that increased temperatures could lead to more photosynthesis, which acts as a negative feedback by absorbing carbon dioxide from the atmosphere.

💡Respiration

Respiration is the process by which living organisms convert biochemical energy from nutrients into adenosine triphosphate (ATP) and then release waste products. In the context of the video, respiration is mentioned as a process that cannot occur without water, linking it to the water cycle, and it also plays a role in the carbon cycle by releasing carbon dioxide back into the atmosphere.

💡Deforestation

Deforestation is the removal of a large area of forest or trees without sufficient reforestation. The video mentions deforestation as a human activity that can disrupt the natural water and carbon cycles. It reduces the number of trees available for photosynthesis, which in turn affects the carbon cycle, and can also alter local water cycles by changing rates of evaporation and transpiration.

💡Cryosphere

The cryosphere comprises the parts of the Earth's surface where water is in its frozen state, including ice caps, glaciers, and sea ice. In the video, it is discussed how changes in the carbon cycle, driven by climate change, can impact the cryosphere by causing ice caps and glaciers to melt, which can lead to rising sea levels and contribute to changes in the water cycle.

Highlights

Water and carbon cycles are essential building blocks for life on Earth.

Both water and carbon are continuously cycled around Earth systems in a closed system at a global scale.

The Earth's lithosphere, biosphere, atmosphere, hydrosphere, and cryosphere are shared stores for both cycles.

Water and carbon cycles experience temporal and spatial changes.

Water is an essential component in the transfers within the carbon cycle.

Water vapor is a greenhouse gas that affects the carbon cycle.

Changes in the carbon cycle can impact water stores and transfers.

Human activities like climate change and deforestation significantly impact both cycles.

Agriculture impacts both the water and carbon cycles.

Positive feedback loops amplify changes within systems.

Melting of permafrost due to temperature rise releases more greenhouse gases.

Increased ocean temperatures can lead to increased evaporation and greenhouse gas concentrations.

Warmer oceans can release dissolved CO2, contributing to positive feedback loops.

Decrease in sea ice due to warmer oceans leads to reduced albedo and temperature rise.

Increasing levels of drought and wildfires due to temperature rise release carbon dioxide.

Negative feedback loops have a diminishing effect and lead to dynamic equilibrium.

Warmer temperatures can increase photosynthesis, absorbing CO2 and leading to a cooling effect.

Increased evaporation can lead to increased cloud cover, reflecting sunlight and causing a cooling effect.

Transcripts

within this video we're going to

consider

some of the links that exist between the

water and carbon cycles

and we're also going to think about how

some of those links can be demonstrated

by the concept of different feedbacks

that occur

as a result of changes so if you think

about what maybe the water and carbon

cycle have in common

to start with the first most obvious

thing

that applies to both of those cycles is

that both water and carbon

we can consider them as being essential

building blocks for life on earth

without water or without carbon

life can't exist on the planet so

they're very very fundamental

both of these elements are also

continuously

cycled around the earth systems

in a closed system at a global scale

so we have a limited amount of water and

a fixed amount of carbon

on the planet and both of those cycles

can be considered as systems with stores

and transfers and flows

moving either water or carbon between

the main stores

water and carbon cycles also share

similar stores so for example

the earth's lithosphere is a store of

both water and carbon

the same for the biosphere the same for

the atmosphere

and the hydrosphere and the cryosphere

as well

both of these cycles also experience

changes and they experience

changes temporally or changes over time

so for example seasonally the water

cycle and carbon cycle experience

changes in the long term they are

experiencing dynamic

equilibrium certainly if we factor out

human activity

these cycles can also experience spatial

variations

so for example we can consider how

perhaps rates of

evaporation or rates of photosynthesis

are also much

higher in areas with warmer climates

such as in the tropics

in order to understand the links we can

also consider the fact that water is an

essential component

in some of the transfers happening

within the carbon cycle

so for example photosynthesis and

respiration

can't happen without the presence of

water

so you could argue that the water cycle

is in fact influencing the carbon cycle

we can think about it the other way as

well

water vapor is a greenhouse gas so that

in turn is going to affect the carbon

cycle because

with increased amounts of water vapor in

the atmosphere

the carbon cycle will be affected a

result of climate change

changes that take place within the

carbon cycle can also impact on water

stores and transfers

so for example any warming that might

happen

as a result of changes to the carbon

cycle as a result of climate change

that could impact maybe the stores of

water such as ice caps and glaciers

cryosphere would be affected by and both

of these

cycles can be impacted or influenced by

similar human activities

so if we take the two activities of

climate change that we've mentioned

and also deforestation both of those

activities can have significant impacts

on disrupting

the natural water and carbon cycles that

exist on the planet

agriculture would be another example of

a human activity that has an impact on

both of those cycles

in order for us to understand some of

these links in a little bit more detail

it's important that we also consider the

different types of feedback

that link these two cycles together

so perhaps if we start by considering

the concept of

positive feedback

positive feedback is a feedback that has

an

amplifying effect so any changes that

happen

within a system if it experiences

positive feedback those changes are

going to get more and more severe

each time we can think about how some of

these operate within the carbon cycle

so let's take for example the

temperature rise that happens

as a result of climate change

if we think about what the knock-on

effects of that temperature rise could

be

we can start to unpick some of the

feedbacks so for example

as a result of temperature rises caused

by

climate change we might experience the

melting

of permafrost this could happen

in high latitude areas like northern

canada

northern russia as a result of the

melting of that permafrost

we are going to release more greenhouse

gases

so more greenhouse gases

are going to end up in our atmosphere

as a result of the melting of that

permafrost

and we can see if we think back to what

we know about the enhanced greenhouse

effect

then if we've got more greenhouse gases

in our atmosphere that in turn

is going to lead to a temperature rise

so there we have

one example of positive feedback

we can think about the impact of this

temperature rise having other influences

as well

so as a result of temperature rise we

also might find

that ocean temperatures will increase

if ocean temperatures increase that in

turn

could lead to there being increased

levels of

evaporation we know that water vapor

is a greenhouse gas and therefore we can

see

how that in turn would lead to increased

concentrations of greenhouse gases in

our atmosphere

now these ocean temperatures might cause

other things to happen as well

another example might be that as oceans

get warmer

any co2 that has been dissolved within

the ocean is going to be released as

that ocean gets warmer

that in turn is going to add carbon

dioxide

into our atmosphere thereby creating

another

of these positive feedback loops

another impact of the increase in ocean

temperatures

might be to cause a decrease in the

amount of sea ice

as oceans get warmer the extent

and the coverage of that sea ice is

going to diminish now sea ice is

normally

very reflective it has what we call a

high albedo it reflects a lot of

sunlight but if the sea ice disappears

then that reflectivity is going to be

lost so we can think about the loss of

sea ice

leading to reduced albedo

in simple terms that means that more

sunlight

is going to be absorbed

at the earth's surface if that happens

we will also

experience a temperature rise so there

we have another

positive feedback loop you can also

maybe consider

how some of these impacts might

affect the biosphere so as a result of

temperature rise

we might have increasing levels of

drought

areas are likely to become hotter and

drier as a result of climate change

that in turn could lead to the increased

intensity or frequency of wildfires

and those wildfires in turn are going to

release

carbon dioxide which will create another

of these positive feedback loops so we

can see that as a result of

one change which is the increase in the

temperature

as a result of human activity the result

of this

one change we get several

positive feedback loops occurring and

this would amplify

those changes causing the temperature

rise to happen more and more quickly

it's also important that we can consider

the concept of

negative feedback as well so negative

feedback does the opposite

to positive feedback it actually has a

diminishing

effect so any changes that take place

within a system

are going to be diminished and

ultimately negative feedback

that leads to dynamic equilibrium

these are feedbacks that occur that

bring things back to normal

so again if we started with our initial

situation where by maybe we had

increased

temperatures so we think about that

concept of global warming again

and we think about temperatures

increasing as a result of that

that could kick-start some negative

feedbacks

so one of the things that might happen

as a result of those warmer temperatures

is um more photosynthesis

could happen temperature is a

determining factor in the rate of

photosynthesis

so if that happened that would absorb

greenhouse gases and particularly carbon

dioxide from our atmosphere

so we'd have fewer greenhouse gases

in the atmosphere as a result of

photosynthesis

if that was to happen we would

ultimately

experience a cooling effect

and we wouldn't crucially get this link

back to the increased temperatures that

wouldn't happen

so the increase in temperature has

kick-started a negative feedback

which has brought things back to normal

it's diminished that change and it's

brought about

some dynamic equilibrium now there

aren't as many

negative feedbacks as there are positive

feedbacks in relation to the water and

carbon cycles

but another important one actually links

back to one that we mentioned a moment

ago which was

increased levels of evaporation

now as well as putting water vapor into

the atmosphere

increased evaporation will also

lead to increased cloud cover

clouds play an important role in terms

of reflecting

any sunlight

that might hit them they don't reflect

all of it obviously but they do reflect

some sunlight

and as a result of that we would

experience

again a cooling effect not

taking us back to that initial change

which was the increase

in temperature so we can see here how

some of those

negative feedbacks also help us to

understand

some of the links between the water and

carbon cycles