Lesson video

Hello and welcome.

My name is Ms. Harrison.

I'm so excited to be learning with you today.

Today's lesson is called "Threats associated with climate change in the rainforest." Grab everything you might need for today's lesson and let's begin our learning.

By the end of today's lesson, you'll understand that tropical rainforests are indirectly threatened by climate change.

Before we can begin this learning, we needed to define the keywords that we'll be using throughout today's lesson.

The keywords in today's lesson are climate change, indirect, and threat.

Climate change, this is a long-term shift in temperature, rainfall, and weather patterns which has had natural causes in the past but is now due to human activities.

Indirect, these are effects or consequences that are not immediately caused by an event or action but happen as a result of it.

Threat, this is something that poses a danger or harm to an environment, species, or ecosystem.

Now that we've defined these keywords, we can begin our learning.

The first question we're going to explore in today's lesson is, how does climate change affect rainforests? Tropical rainforests are considered biodiversity hotspots, meaning they are home to a huge variety of species.

They're essential for life on Earth because they provide a wide range of crucial environmental services.

First, tropical rainforests absorb CO2 from the atmosphere, playing a key role in reducing the amount of carbon dioxide, a greenhouse gas, and helping to mitigate climate change.

By absorbing carbon, these forests help regulate the Earth's climate and maintain a balance of gases in the atmosphere.

Secondly, tropical rainforests help regulate climates globally and locally.

They're often referred to as the lungs of the Earth because of their role in producing oxygen and stabilising atmospheric temperatures.

Rainforests also influence rainfall patterns, both for the local areas and beyond, by generating moisture that is released into the atmosphere.

Tropical rainforests also provide habitats for an incredible number of species, many of which can be found nowhere else on Earth.

The warm temperatures and consistent rainfall allow for rich diversity of plants, animals, insects, and fungi to thrive in these ecosystems. Many species rely on their unique conditions of the rainforest to survive, making the rainforest an irreplaceable part of the global biodiversity.

In addition, rainforests offer important resources to humans such as timber, fruits, medicine, and oils.

Many medicines used today come from plants found in tropical rainforests, and people around the world rely on these resources for their survival and economic activities.

Climate change refers to the long-term shift or alteration average temperature, rainfall patterns, and the frequency of extreme weather events on Earth.

Unlike short-term weather changes which can vary from day to day, climate change is about the trends and patterns that happen over decades or centuries.

Climate change can result in a higher than average global temperature due to the buildup of greenhouse gases like carbon dioxide in the atmosphere.

These gases trap heat, creating a greenhouse effect that warms the planet.

Changes in rainfall patterns may lead to more frequent droughts in some areas, while other regions may experience heavier rainfalls or increased flooding.

Extreme weather events such as hurricanes, heat waves, and blizzards may also become more common or intense due to climate change.

These shifts are already affecting ecosystems, food production, sea levels, and human activities, making understanding and addressing climate change a priority for the global community.

Climate change directly affects tropical rainforests in several ways.

I would like you to pause the video here whilst you have a think, how does climate change affect the tropical rainforest? And press play when you're ready to continue.

Excellent, the way climate change affects the tropical rainforest is by higher temperatures, increased frequency of storms, and changes in rainfall.

The 2023 Amazon drought was one of the worst in recent history and was caused by a combination of factors linked to climate change.

One major factor was rising temperatures, which made the region much hotter than usual.

These high temperatures caused more water to evaporate from rivers, lakes, and the soil, leading to drier conditions across the Amazon.

Another contributing factor was changing rainfall patterns.

The Amazon relies on regular rainfall to maintain its ecosystem, but climate change has caused shifts in these patterns, making rain less predictable and less frequent.

This has intensified drought conditions, with some areas experiencing much less rainfall than normal.

As a result of these extreme conditions, 7,000 wildfires were reported in the Amazonas state in September 2023.

The dry conditions made the forest more vulnerable to fires which can spread quickly and destroy large areas of rainforest.

These wildfires further damage the ecosystem, harming plants and animal life and releasing more carbon into the atmosphere, which contributes to global warming.

The 2023 Amazon drought highlights the dangerous impact of climate change on sensitive ecosystems like the Amazon rainforest and the importance of addressing rising temperatures and changing rainfall patterns to protect our planet.

As you can see on the diagram on your screen, this is a choropleth map showing the extreme intensity of the drought from June to November 2023 in the Amazon rainforest.

I would like you to identify the causes of the Amazon's drought in 2023.

Was it A, increased volcanic activity; B, rising temperatures; C, rising sea levels; or D, changes in rainfall patterns? Pause the video here whilst you attempt this task and press play when you're ready to continue.

Fantastic, the answers are B, rising temperatures, and D, changes in rainfall patterns.

Well done if you managed to identify those correctly.

True or false? Climate change has not impacted tropical rainforests as temperature and rainfall patterns have remained the same.

Pause the video here whilst you decide if this statement is true or false and press play when you're ready to continue.

Fantastic, this statement is false.

I would now like you to explain why.

Pause the video here and press play when you're ready to continue.

Excellent, the reason why this statement is false is because climate change has affected tropical rainforests by increasing temperatures, changing rainfall patterns, and increasing the frequency of droughts.

For example, the Amazon rainforest experienced its worst recorded drought in 2023.

Well done if you managed to explain that correctly.

I would now like you to define climate change.

Andeep has said, "Are we talking about natural climate change or climate change resulting from human activities?" I would like you to address both in your answer.

Pause the video here whilst you attempt this task and press play when you're ready to continue.

Fantastic, let's check our answer.

Your answer should include the following points.

Climate change refers to long-term changes in the Earth's average weather patterns, which has happened many times in Earth's history from natural causes but which is now resulting from the increase in global temperatures due to human activities like burning fossil fuels.

Well done if you managed to explain that correctly.

We're now going to explore our second question of today's lesson, what are indirect threats to the rainforest? Direct threats are actions that immediately remove or destroy the rainforest vegetation.

One example is logging where trees are cut down for timber, which reduces the forest's size and disrupt the habitat for countless species.

Another direct threat is deforestation for farming or mining.

Trees are cleared to make way for agriculture such as crops like soy or palm oil, or to create space for cattle ranching.

Mining operations also remove large sections of rainforest for valuable resources like gold, copper, and other minerals.

These actions directly destroy the rainforest ecosystem and contribute to habitat loss and species extinction.

On the other hand, indirect threats don't immediately destroy the rainforest, but they will create conditions that make it more likely that the rainforest will be harmed.

For example, the increased global demand for minerals encourages mining in rainforest regions.

As demand for resources like gold, oil, and timber rises, more pressure is placed on forests to meet this need, often resulting in unsustainable practises.

Similarly, climate change caused by rising sea levels of carbon dioxide can increase temperatures and alter rainfall patterns, making rainforests more vulnerable to droughts and wildfires which can further degrade the environment.

Both direct and indirect threats are contributing to the rapid loss of the rainforest, making conservation efforts even more crucial to protecting these vital ecosystems. Climate change is an indirect threat to the health of rainforests because it creates conditions that make rainforests more vulnerable to damage.

One key way this happens is through a feedback loop.

As the Earth warms due to rising greenhouse gases, temperatures increase and rainfall patterns become unpredictable.

This can lead to droughts in areas that were once constantly wet, affecting the rainforest's ability to thrive.

When rainforests face drought, trees and plants suffer and then the growth slows down, making it harder for the ecosystem to thrive, causing ecosystem stress.

This drying of the forest can then lead to another problem, wildfires.

Rainforests are not naturally fire prone, but when they become dry due to climate change, they become more susceptible to fires which can quickly spread and destroy large areas of the forest.

As these fires burn, they release carbon dioxide and other greenhouse gases that were stored in the trees.

This increases the amount of carbon in the atmosphere, contributing even more to global warming.

This is where the feedback loop comes in.

The burning of trees releases carbon, which worsens climate change, which in turn makes the rainforest more vulnerable to droughts and fires.

This creates a cycle that is difficult to break as each step makes the next one more likely.

If this cycle continues, rainforests could become more degraded, contributing to further climate change and loss of biodiversity.

In the cloud forests of the Andes, the forests depend on consistent cloud cover to maintain the moisture they need to thrive.

The cooler moist conditions created by the clouds are essential for the survival of many species such as orchids, frogs, and rare birds that are adapted to these humid environments.

However, as global temperatures rise due to climate change, the clouds are now forming higher up in the mountains.

The shift in cloud formation means that the lower regions where these species live are now becoming too dry.

Without the constant cloud cover, there is not enough moisture for the plants and animals that depend on it, leading to stress in the entire ecosystem.

Species like orchids, which need a high level of humidity, struggle to survive, while other creatures such as certain types of frogs and rare birds are facing a loss of habitat.

This change is particularly concerning because these species are often highly specialised to the specific conditions of the cloud forest.

As the climate warms and the clouds cover shifts, the habitat they depend on is shrinking and they're increasingly vulnerable.

This situation highlights how climate change can disrupt delicate ecosystems and even in remote areas like the Andes, putting immense pressure on biodiversity.

I would like you to think about some examples of ecosystem stress in the tropical rainforest.

Pause the video here whilst you attempt this task and press play when you're ready to continue.

Fantastic, some examples of ecosystem stress in the tropical rainforest are biodiversity loss, disruptive food webs, changes in water cycle, soil degradation, pests and diseases, wildfires, changes in carbon storage, and displacement of indigenous people.

I would now like you to add the missing labels of ecosystem stress to this diagram.

Pause the video here whilst you attempt this task and press play when you're ready to continue.

Excellent, the missing labels on this diagram are pests and diseases, displacement of indigenous communities, and changes in water cycle.

Well done if you managed to identify those correctly.

Biodiversity loss is a growing concern due to rising temperatures which are pushing many plants and animals towards extinction.

The impact of warmer climates is particularly evident in ecosystems that are sensitive to temperature changes such as tropical rainforests.

One major factor is that species in these ecosystems are often highly specialised to their environment.

For example, species that rely on high humidity, like many amphibians and certain plants, struggle to survive as temperatures rise and conditions become hotter and drier.

These species have evolved to live in environments with consistent moisture, and as the climate changes, their habitats are no longer suitable, making it difficult for them to thrive.

In tropical rainforests, the temperatures stay fairly stable throughout the year with minimal seasonal variation.

This stability means that many animals in these areas are not adapted to cope with hotter seasons or more extreme weather.

As the climate warms, animals like insects, birds, and mammals may find it harder to find food, reproduce, or even survive.

Rising temperatures also have significant impact on breeding and migration patterns.

Many species rely on specific temperatures to trigger breeding or migration.

But with warmer climates, these patterns are being disrupted.

For example, some animals may breed too early or too late, or they may migrate to areas that no longer provide the resources they need.

This disruption leads to reduced food availability and declining species survival.

As a result, rising temperatures are not only pushing species towards extinction, but they're also altering entire ecosystems and food webs, making it more difficult for biodiversity to thrive.

True or false? Rising temperatures improve the health of the rainforest biome because animals and plants are adapted to tropical conditions.

Pause the video here whilst you attempt this task and press play when you're ready to continue.

Fantastic, this statement is false.

I would like you to explain why.

Pause the video here and press play when you're ready to continue.

Brilliant, the reason why this statement is false is because higher temperatures put stress on rainforest ecosystems and can lead to reduced biodiversity as many animal species are adapted to stable rainforest temperatures and cannot tolerate an increase in temperature.

Excellent work on this.

When certain plants die or struggle to survive due to climate stress, it can lead to a disruption of an entire food web.

Plants are at the base of food webs and without them, the entire ecosystem begins to fall apart.

For example, when climate stress such as rising temperatures or drought causes certain plants to stop growing or die off, it directly affects the herbivores that rely on these plants for food.

These herbivores, such as insects, small mammals, and grazing animals, no longer have the food they need to survive, causing their populations to decline.

As the number of herbivores declines, it creates problems for their predators, such as carnivores like wolves, big cats and birds of prey that rely on herbivores for food.

If the prey species become too scarce, the predators struggle to find enough food to eat, which can lead to further imbalances in the ecosystem.

Additionally, many plant species rely on pollinators like bees, butterflies, and birds for reproduction.

If pollinator populations also begin to decline, plant reproduction is further reduced.

Without pollinators to fertilise flowers, many plants cannot produce seeds or new growth, leading to even fewer plants in the ecosystem, which further harms herbivores and the predators that depend on them.

In this way, climate stress on plants causes a ripple effect that can disrupt the whole food web, affecting species all the way up the chain.

This shows how interdependent life in an ecosystem truly is and how climate change can have wide-reaching effects on biodiversity.

Climate change is having a significant impact on water cycles in the tropical rainforest, which are vital ecosystems for regulating water flow and maintaining balance in the environment.

One major effect of rising temperatures is that they lead to faster evaporation from water bodies such as rivers, lakes, and soil.

This means that the available water in the rainforest is lost more quickly, reducing the amount of moisture that can be absorbed by plants, trees, and the soil.

As a result, less water is available for both the ecosystem and the organisms that depend on it.

In addition to increased evaporation, altered rainfall patterns are experiencing more intense rainfall, which can lead to flooding, while others are facing droughts as rainfall becomes less predictable.

These changes make it more difficult for the rainforest to maintain its usual water balance, which can negatively affect plant growth, animal habitats, and even the availability of clean water for human use.

Changes in vegetation also have an impact on the water cycle.

As the forest faces stress from climate change, some plants may die or fail to grow as quickly as before.

This reduces the amount of water that can be absorbed by plants and trees, which in turn affects the groundwater levels.

The loss of vegetation also reduces the ability of plants to release water into the atmosphere through transpiration, further disrupting the water cycle.

Soils in the tropical rainforests are low in nutrients because of the rapid cycling of nutrients between plants, animals, and the soil.

Plants absorb nutrients and when they die, decomposition quickly returns the nutrients to the soil, keeping it fertile.

However, climate change is disrupting this process.

Changes in rainfall patterns, including droughts, have led to drier soils.

As the soils dry, it becomes hard-packed and infertile, reducing its ability to support plant growth.

The lack of moisture also slows decomposition, meaning fewer nutrients are returned to the soil and plants then struggle to grow.

This leads to further degradation of the rainforest ecosystem as fewer plants can grow, affecting animals that depend on it.

How does a reduction in rainfall affect the soil in the tropical rainforest? Is it A, increases soil fertility, making easier for plants to grow; B, causes soil to become dry, infertile, and hard-packed; C, improves soil moisture, enhancing plant growth; D, has no effect on soil quality? Pause here whilst you decide which statement is correct and press play when you're ready to continue.

Fantastic, the correct answer is B.

It causes soil to become dry, infertile, and hard-packed.

Well done on this task.

As temperatures and humidity levels change due to climate change, tropical rainforests are seeing more outbreaks of pests and diseases.

Rising temperatures and increased habitat destruction are allowing diseases to spread into new areas that were previously unaffected.

Plants in tropical rainforests are adapted to local pests, but the introduction of new pests and diseases can cause significant damage.

These new pests spread easily in changing climates and many trees and plants which haven't evolved defences against them start to die.

The spread of new diseases weakens key plant species, which disrupts the food webs and impacts overall biodiversity.

As certain plants die off, herbivores that rely on them for food may struggle to survive, and animals that depend on those herbivores will also be affected.

This ripple effect can weaken the entire ecosystem, making it less resilient to further climate change.

In the Amazon rainforest, warmer temperatures due to climate change have allowed pests like the cocoa pod borer to spread into new areas.

This pest, which damages cacao crops, has become a serious threat to both agriculture and the forest health.

The spread of the cocoa pod borer is damaging crops particularly in the cacao industry, which is a major economic activity in the region.

To protect the crops, farmers are resorting to using polythene sleeves to cover the cacao pods.

While this can help reduce damage from the pests, it is expensive and labor-intensive solution.

Wildfires in the Amazon are primarily caused by human activities, particularly deforestation and farming.

As forests are cleared for agricultural use, vegetation becomes dry and more susceptible to fire.

Climate change is making forests even drier, increasing the likelihood of wildfires occurring naturally.

These fires have devastating effects on the ecosystem.

They destroy habitats, degrade soil, and disrupt food chains, as many species lose their homes and food sources.

Wildfires also emit large amounts of CO2 into the atmosphere, further contributing to global warming.

They can alter rainfall patterns, reducing the amount of moisture in the environment, making it harder for the rainforest to regenerate.

Overall, wildfires weaken the entire ecosystem, making it more vulnerable to further damage.

In 2019, the Amazon experienced more than 89,000 fires, and with the majority being caused by human activity, particularly deforestation and agriculture.

These fires burned over 7.

6 million hectares of forest, which is a huge area and highlights the scale of destruction.

The wildfires had severe consequences.

They destroyed habitats, causing many species to lose their homes, and they degraded the soil, making it less fertile and harder for the forest to regenerate.

In addition, these fires released an alarming 228 megatons of CO2 into the atmosphere, further contributing to global warming and climate change.

During this period, satellite imagery and GIS layers showed the intensity and spread of wildfires, with many occurring between the 21st and 22nd of August in 2019, a critical time for assessing the extent of damage.

This event demonstrated the link between human activities and increasing risk of wildfires in the Amazon.

Rainforests are losing their ability to store carbon.

Climate stress is making trees grow more slowly.

Dead trees don't store carbon.

Deforested areas store even less carbon.

More wildfires release more carbon dioxide.

And hot conditions mean decomposers work faster, releasing more carbon dioxide.

Some parts of the Amazon rainforest now emit more carbon dioxide than they absorb.

Instead of mitigating climate change, for example, by reducing the concentration of greenhouse gases in the atmosphere, some tropical rainforest regions are now actually adding to global warming.

This is a climate change feedback loop.

As we can see on our graph, this is showing the different parts of the Amazon and their carbon dioxide emissions per year.

If an area has negative numbers, this means that the area absorbs more carbon dioxide.

This makes it a carbon sink.

Positive numbers mean the area releases more carbon dioxide, making it a carbon source.

Many indigenous communities have lived in rainforests for thousands of years, and some rainforest environments are actually adapted to being managed by humans.

For example, clearing patches of the forest in a sustainable way can allow new trees to grow, helping to maintain the balance of the ecosystem.

However, as rainforests continue to decline due to climate change and deforestation, these communities are facing significant challenges.

For example, as temperatures rise and rainfall patterns shift, rivers and other water sources are drying up, making it harder for these communities to access clean water for drinking, farming, and daily life.

The destruction of forests and the loss of species means that the trees and animals these communities depend on for food are disappearing.

Increased temperatures also affect plant growth and wildlife populations, leading to a decrease in available resources.

With their land becoming increasingly uninhabitable, many indigenous groups are forced to migrate in search of resources, leaving behind the traditional ways of life and cultural heritage.

These impacts show the strong connection between human communities and the environment.

For thousands of years, humans have been integral to the health of rainforests, but now their survival is threatened by the ongoing decline of these vital ecosystems. I would like you to identify two ways climate change will negatively impact indigenous communities in the tropical rainforest.

Is it A, loss of food sources as trees and animals disappear; B, local fish supplies increase due to warmer temperatures; C, water shortages as rivers dry up; D, more space to build homes as trees die out? Pause the video here whilst you attempt this task and press play when you're ready to continue.

Fantastic, the two ways climate change will negatively indigenous communities is A, loss of food sources as trees and animals disappear, and C, water shortages as rivers dry up.

Well done on this task.

I would now like you to identify the regions that emit more carbon dioxide than they absorb.

Is it A, Central Amazon; B, Eastern Amazon; C, Northern Amazon; D, Southern Amazon; E, Western Amazon? Pause the video here whilst you attempt this task and press play when you're ready to continue.

Excellent, the answers are A, Central Amazon, B, Eastern Amazon, and D, Southern Amazon.

Well done on this task.

True or false? Rainforests are increasing their ability to store carbon, even as trees die from drought, heat stress or wildfires.

Pause the video here whilst you attempt this task and press play when you're ready to continue.

Fantastic, the answer is false.

I would like you to explain why.

Pause here and press play when you're ready to continue.

Excellent, the reason why this statement is false is because when trees die from drought, heat stress or wildfires, they release carbon dioxide into the atmosphere instead of absorbing it, reducing the forest's ability to store carbon and contributing to climate change rather than mitigating against it.

Well done if you managed to explain that correctly.

I would now like you to complete this table about ecosystem stress in the tropical rainforest resulting from climate change.

I would like you to focus on wildfires, biodiversity loss, and pests and diseases.

I would like you to provide a description and an example for each.

Pause here whilst you attempt this task and press play when you're ready to continue.

Excellent, let's check our answers.

Your answers might include some of the following points.

For wildfires, wildfires in the Amazon are mainly caused by humans.

Climate change makes the forest drier, increasing the fire risk.

These fires release carbon dioxide and destroy habitats, threatening species.

In 2019, the Amazon experienced more than 89,000 fires.

They burned over 7.

6 million hectares, destroying habitats and degrading soil.

Biodiversity loss, changes in climates affect species' habitats, leading to a decline in biodiversity as plants and animals struggle to adapt or find suitable environments.

In the Andes cloud forests, rising temperatures cause clouds to form higher up, leaving lower areas too dry for orchids, frogs and rare birds.

Pests and diseases.

Climate change causes warmer temperatures and altered humidity, enabling pests and diseases to spread faster, threatening plants and animal life.

The Amazon rainforest has warmer temperatures which have allowed pests like the cocoa pod borer to spread, damaging crops and impacting forest health.

Well done on that task, you've done brilliantly.

We've now come to the end of our learning in "Threats associated with climate change in the rainforest," and you've done amazingly.

Before we end this lesson, let's summarise everything we've learned in today's lesson.

Climate change refers to long-term changes in temperature and weather patterns that are altering ecosystems across the globe.

For the tropical rainforest, climate change is having a particularly significant impact.

Rising temperatures and altered rainfall are two of the most noticeable effects of climate change.

These changes place enormous stress in the ecosystem as rainforests are typically adapted to a very specific climate.

Higher temperatures can lead to droughts and erratic rainfall can disrupt the delicate balance needed to support the wide variety of plant and animal life.

As a result, these indirect threats to the health of the rainforests put immense pressure on the species that call it home.

The consequences are far-reaching.

Biodiversity loss is a major issue as species struggle to survive in the changing conditions.

Many plants and animals are unable to adapt quickly enough to warming temperatures and changing weather patterns, leading to declines or even extinctions.

As species disappear, the rainforest's resilience weakens and its ability to provide critical services like absorbing carbon dioxide, regulating water, and sustaining complex food webs is greatly diminished.

Adding to this, there are positive feedback loops in the system.

These are cycles where the impacts of climate change actually accelerate the problem.

For instance, when the rainforest is distressed, whether by drought, fire, or other factors, it releases more carbon dioxide into the atmosphere.

This is because trees which act as carbon sinks die or are burned in wildfires, reducing the forest's capacity to absorb carbon.

As more carbon dioxide is released, the atmosphere warms further, intensifying the impacts of climate change.

This creates a vicious cycle that continues to increase global temperatures and further disrupts the rainforest ecosystem.

In the long term, the effects of climate change in the tropical rainforest are not only a concern for the rainforest itself, but also for the entire planet.

The loss of biodiversity, weakening ecosystems, and increasing atmospheric carbon dioxide further exacerbate global climate change, leading to more widespread environmental instability.

Well done on today's lesson, you've done brilliantly, and I look forward to learning with you again very soon.