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 "Deforestation in the Tropical 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 the causes and changing rates of deforestation.

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

The keywords are deforestation, biodiversity, and subsistence farmers.

Deforestation, this is the large scale removal or clearing of forests.

Biodiversity, this is a measure of how many different species live in an ecosystem.

Subsistence farmers, these are farmers that grow only enough food for themselves.

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

The first question we are going to explore in today's lesson is, what is happening to tropical rainforests? Deforestation is the large-scale removal or clearing of forests, often leading to their permanent destruction.

Around the world, especially in the tropical rainforest, this is a growing crisis.

Vast areas of lush biodiverse forests are being cut down for agriculture, urban expansion, and logging.

This not only threatens wildlife and plant species, but also contributes to climate change by reducing the earth's natural ability to absorb carbon dioxide.

Protecting our forest is crucial for the health of our planet and future generations.

Tropical rainforests are often referred to as biodiversity hotspots as they're home to over 50% of the world's plants and animal species.

These ecosystems host an incredibly diverse range of life forms, many of which are found nowhere else on earth.

This includes everything from the tallest trees and the smallest insects to iconic animals such as orangutans and jaguars.

However, deforestation of tropical rainforests pose significant threat to those remarkable biodiversity.

As rainforests are cleared for agriculture, logging and urbanisation, countless species lose their habitats.

It is estimated that around 1000 species are lost each year with many others facing the risk of extinction in the near future.

Species like the orangutan, jaguar, and numerous other plants and animals are classified as vulnerable or endangered due to habitat loss caused by deforestation.

The loss of biodiversity in tropical rainforest is not just a tragedy for the species involved, but also has far-reaching consequences for ecosystems and human societies.

Many species in rainforests play vital roles in maintaining the balance of the ecosystem, such as pollinating plants, controlling pests, and distributing seeds.

Without these species, entire ecosystems could collapse, disrupting food chains and vital services like soil regeneration and carbon storage.

Furthermore, many of the plants and animals found in rainforests have potential benefits for medicine, agriculture, and science, meaning their extinction could also hinder the advancement in these fields.

In short, deforestation of tropical rainforests is a threat to more than just the forest itself.

It jeopardises the biodiversity that sustains the planet, impacts the ecosystem that we all depend on, and diminishes the potential benefits that rainforests offer humanity.

Rainforests are called the lungs of the earth because they act as carbon sinks by taking in carbon dioxide and release oxygen.

When trees are cut down, the carbon dioxide they stored is released back into the air when the wood is burned or rots, making climate change worse.

Let's take a closer look at this.

Rainforest plants remove carbon dioxide from the atmosphere.

Trees store masses of carbon for years.

This reduces the greenhouse effect.

Deforestation reduces the amount of carbon taken by trees from the atmosphere.

Burning felled trees or letting them rot add stored carbon back to the atmosphere.

Every year around 10 million hectares of tropical rainforests are lost through deforestation.

To put that into perspective, this is an area roughly the size of Iceland, or about 15 Premier League sized football fields every minute.

This rapid loss of forest area has significant impacts on both the environment and global climate systems. As we can see in the graphic, the countries with the highest rates of deforestation are primarily located in tropical regions where rainforests are most prevalent.

These countries are often driven by factors like agriculture, mining, and urban development, which leads to the clearing of vast forest areas.

While these activities might bring short-term economic benefits, they have long-term environmental costs including loss of biodiversity, disruption of the water cycle, and increased carbon emissions that contribute to climate change.

The scale of deforestation is alarming, and it is crucial that we work together to find solutions that balance economic growth with the protection of our plants' vital ecosystems. Let's test our knowledge.

How much more tropical rainforests did Brazil lose then Bolivia in 2023? Is it: A, 0.

49 million hectares.

B, 0.

53 million hectares.

C, 0.

65 million hectares.

Or, D, 0.

73 million hectares.

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

Excellent, the answer is C, 0.

65 million hectares.

Well done if you managed to identify that correctly.

Over the years, deforestation rates have fluctuated for several reasons.

One being economic factors.

The demand for timber, crops, and minerals can either increase or decrease deforestation.

Political factors, government policies, land rights and enforcement laws have shaped the pace of deforestation.

Environmental factors, climate change and natural disasters influence deforestation rates.

Tropical rainforests weren't always heavily cleared.

This began to change the demand for land, for agriculture, and for resources like timber and iron increased.

Let's take a look at this.

In the pre-industrial era, there was small scale agriculture, but as we went into the industrial revolution, the demand for timber, agriculture, and infrastructure projects increased.

In the 20th century, we saw large-scale agriculture logging and mining happening, which increased deforestation rates.

However, in the 21st century, we've started to see that deforestation rates are slowing in some regions, and this is because of conservational efforts and environmental policies.

The graph on your screen is showing the changing rates of primary tropical forest loss between 2012 and 2023.

Non-fire related forest loss is the main cause of deforestation, ranging between 2.

5 and 3.

8 million hectares.

It's really important to know if deforestation is caused by forest fires because they cause rapid damage which releases more carbon and makes land harder to recover.

There was a sudden spike of 2.

4 million hectares being lost in 2016 for fire-related causes.

This was the largest amount throughout this whole period on this graph.

Then we've also noted that in 2016 and 2017, they were also the years with the highest non-fire related loss, reaching 3.

8 million hectares.

Which of the following factors have not contributed to increasing rates of deforestation? Is it: A, high demand for timber and agricultural products.

B, enforcement of laws that protect biodiversity.

C, increase in forest regeneration, for example, replanting projects.

Or, D, increase in droughts in tropical rainforest regions.

Pause the video here whilst you decide which of the factors have not contributed to increasing rates of deforestation, and press play when you're ready to continue.

Excellent, the answers are B, enforcement of laws that protect biodiversity, and C, increase in forest regeneration, for example, replanting projects.

Well done if you managed to identify those correctly.

True or false, deforestation rates in tropical rainforests have only increased over the past century with no periods of slowdown.

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

Excellent, this statement is false.

I would now like you to explain why this statement is false.

Pause here and press play when you're ready to check your answer.

Fantastic, the reason why this statement is false is because deforestation has always occurred.

However, there was a sharp spike in deforestation during the 20th century due to a growing demand of mining, agriculture, and logging.

However, in the 21st century, conservation efforts have produced some periods of reduced rates of deforestation.

Excellent work on this.

I hope you managed to explain that correctly.

I would now like you to use the graph to describe the trend of deforestation of tropical rainforests globally.

To help you answer this question, I provided a frame for you.

I would like you to discuss the trend.

Overall, is it increasing, decreasing, or fluctuating? Provide some evidence.

What numerical data can be used to support the trend? And provide an anomaly.

Is there a period that does not fit this trend? And you have to use evidence to support this statement.

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

Excellent, let's check our answers.

Your answer may have included some of the following points.

Overall, the total global loss of tropical rainforests fluctuates between 2012 to 2023.

Non-fire related tree loss was the main cause of deforestation with rates fluctuating between 2.

5 million hectares and 3.

8 million hectares with spikes in 2016 and 2017.

An anomaly occurs in 2016 when fire-related losses rose to 2.

4 million hectares from 0.

3 million hectares.

Fantastic, I hope you managed to include some of those points and use numerical data to support your answers.

We are now going to explore our second question of today's lesson.

What are the causes of deforestation? I would like you to pause here and have a think of what the causes of deforestation are.

Press play when you're ready to continue.

Fantastic.

Tropical rainforests are attractive to organisations and locals due to the vast amounts of untouched land and natural resources.

Here are some examples of the causes of deforestation.

Cattle ranching, urbanisation, expansion of roads, construction of energy sources, logging for timber, and mining for minerals.

I would now like you to add in the missing causes of deforestation.

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

Excellent, the missing labels are mining for minerals, cattle, ranching, and urbanisation.

Well done if you managed to identify those correctly.

Looking is the process of cutting down trees to harvest their wood, which is used in products like building materials, furniture, and paper.

Some trees such as tropical hardwoods like teak and mahogany are particularly valuable due to their durability and unique appearance.

These valuable woods make tropical rainforests a target for the timber industry with forests being cleared at an alarming rate.

Unfortunately, illegal logging is widespread in many rainforest regions.

The demand for timber remains high, and this illegal activity is driven by weak laws, poverty, and unclear land ownership.

In many cases, local communities and workers have little choice but to engage in illegal logging as a means of survival, while larger, often criminal organisations profit from the exploitation of these forests.

Illegal logging not only leads to the loss of valuable ecosystems, but it also exacerbates issues like deforestation, biodiversity loss, and climate change.

Illegal logging can prevent sustainable forest management practises from being put in place, making it even harder to protect rainforests for the future.

Logging poses several serious threats to tropical rainforests.

One of the most significant impacts is that it causes rainforests to become fragmented, breaking the forest into smaller, disconnected patches.

This fragmentation disrupts the habitat of many species, leaving animals without the space they need to find food, shelter, or mates, which can lead to population declines and even extinction for some species.

Another consequence of logging is increased soil erosion.

When trees are removed, the soil becomes less stable and is more easily washed away by rain.

This leads to landslides, particularly in areas with steep terrain which can damage surrounding ecosystems, agriculture, and communities.

Logging also increases the risk of forest fires.

When large of the forest are cleared, the remaining forest becomes more vulnerable to fires, which can spread rapidly and destroy large portions of the ecosystem.

Fires can also release massive amounts of carbon dioxide into the atmosphere, worsening climate change.

Finally, as trees are cut down, there are fewer trees left to absorb carbon dioxide.

This not only reduces the ability of forests to combat climate change, but also releases stored carbon into the atmosphere, further contributing to the warming of the planet.

Slash-and-burn farming is a method often used by subsistence farmers, particularly in tropical regions.

The process involves cutting down trees and burning forest areas to create fertile soil for crops.

The ash from the fire temporarily enriches the soil with nutrients making it suitable for farming in the short-term.

However, this practise has long-term negative impacts.

Repeated burning over time depletes the soil's nutrients, meaning farmers must continuously move to new areas of the forest to clear land for agriculture.

As a result, rainforests are destroyed, leading to deforestation and soil degradation.

Globally, slash-and-burn farming is responsible for about 15% of deforestation, significantly contributing to the loss of vital ecosystems. This also disrupts the carbon cycle as trees that once stored carbon are burned, releasing carbon dioxide into the atmosphere and contributing to climate change.

Which of the following is a characteristic of the slash-and-burn farming method? A, it involves planting crops and fields without using any fertilisers.

B, it clears land by cutting down trees and burning them to create space for farming.

C, it relies on advanced technology to harvest crops efficiently.

D, it preserves forest areas by planting new trees in the same spot.

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

Fantastic, the answer is B.

It clears land by cutting down trees and burning them to create space for farming.

Well done on this task.

Mining for valuable minerals such as gold, diamond, and other precious metals is another major contributor to deforestation.

To access these minerals, mining operations often use explosives and heavy machinery to clear large areas of rainforest.

This causes immediate disruption to the landscape and disrupts the habitat of countless species.

Once mining operations are completed, the land is often left abandoned with little effort made to restore it.

This lack of rehabilitation can lead to long-term environmental damage such as soil erosion, contamination of nearby water sources with toxic chemicals, and the loss of biodiversity.

The destruction caused by mining can take decades if not centuries to recover.

And in many cases, the land may never fully return to its original state.

In addition to habitat loss and soil degradation, mining also contributes to climate change by removing large amounts of carbon absorbing trees and releasing stored carbon during the process.

This makes mining a significant driver of both deforestation and global warming.

The Carajas mine in Brazil is one of the largest iron ore mines in the world, converting an area equivalent to 1.

3 million football pitches.

While mining operations like these can contribute to the economy by providing jobs and boosting industries, they come with significant environmental costs.

One of the most severe impacts of mining is the destruction of habitats.

Large areas of rainforests are cleared to make way for the mining activities, displacing local wildlife and threatening biodiversity.

As habitats disappear, species lose their home food, sources, and shelter, which leads to the decline in populations, and in some cases, extinction.

Mining also leads to soil erosion.

When forests are removed and heavy machinery is used, the soil becomes loose and is more easily washed away by rain leading to landslides and further degradation of the land.

Additionally, water pollution is a major issue in mining areas.

Toxic chemicals and heavy metals used in the mining process often end up contaminating nearby water sources, which can harm both aquatic life and local communities who rely on these water supplies for drinking and farming.

In summary, while mines may provide economic benefits, they also cause severe environmental damage including habitat destruction, soil erosion, and water pollution.

Rainforests are home to some of the world's largest rivers which make them prime location for building hydroelectric power dams. These dams generate electricity by harnessing the energy of moving water, but their construction can have severe environmental and social consequences.

One of the most significant impacts of building dams is the flooding of large areas of rainforest.

This often leads to the displacement of Indigenous communities who have lived in these forests for generations.

These communities rely on the land for food, shelter, and cultural practises.

And flooding their land can destroy their way of life.

The construction of dams can also lead to the destruction of habitats for countless plants and animal species.

When forests are flooded, the ecosystems are disrupted and wildlife leave their homes, food sources and migration routes often leading to population declines and even extinction.

Additionally, the building of dams can cause changes to water flow and disrupt sediment transportation downstream.

The natural flow of rivers is altered, which can affect water availability for people living downstream.

This disruption can lead to a variety of problems including erosion, changes in water quality, and impact on fish population.

True or false, deforestation is primarily caused by small scale farmers cutting down forests for subsistence farming.

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

Excellent, this statement is false.

I would now like you to explain why the statement is false.

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

Fantastic, the reason why the statement is false is because while subsistence farming does lead to some deforestation, it is mostly caused by large-scale commercial activities such as logging and mining.

Slash-and-burn agriculture is responsible for around 15% of deforestation globally.

Which of the following on negative impacts of building dams in rainforest areas.

Is it: A, restores forest ecosystems by creating new habitats.

B, displacement of Indigenous communities.

C, increases soil erosion leading to increased landslides.

Or, D, increases biodiversity by creating more forested areas.

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

Excellent, the answers are B, displacement of Indigenous communities and C, increases soil erosion leading to increase landslides.

Well done if you manage to identify those correctly.

Cattle ranching is responsible for 50% of global deforestation, making it one of the leading drivers of rainforest destruction.

Large areas of forest are cleared to create pastures for cattle, and this has a range of negative environmental impacts.

First, deforestation is a direct consequence of cattle ranching, as vast tracts of land are cleared for grazing.

This not only destroys rainforests, but also disrupts the biodiversity of these ecosystems. Many species, including those found nowhere else in the world lose the habitats which can lead to extinction.

Another significant issue is soil degradation.

The continuous grazing of cattle can wear down the soil removing vital nutrients, making it more prone to erosion.

Without the tree cover to stabilise the soil, rainfall washes away the top soil, which impacts plant life and can lead to desertification in some areas.

Cattle ranching also contributes to increased greenhouse gas emissions primarily through methane emissions from cattle digestion, and the clearing of forests that would otherwise store carbon dioxide.

This contributes to global warming and climate change.

Finally, the conversion of rainforests into cattle ranches disrupts the local water cycle.

Trees play a crucial role in absorbing and releasing water into the atmosphere, and their removal can lead to changes in rainfall patterns, droughts, and reduce their water availability for both ecosystems and local communities.

Road construction is one of the most destructive causes of deforestation because it opens up previously inaccessible rainforest areas.

Once roads are built, they provide easy access for activities like logging, mining, and agriculture, which lead to widespread exploitation of these fragile ecosystems. A prime example is the Trans-Amazonian Highway in Brazil, which stretches over 4,000 kilometres and cuts through the heart of the Amazon rainforest.

While the highway was originally built for development purposes, it has led to significant environmental damage, particularly by making it easier for illegal activities such as illegal logging to thrive in previously remote areas.

This has caused widespread forest lost, habitat destruction, and biodiversity decline.

The creation of roads also leads to fragmentation of the rainforest, which isolates wildlife populations making it harder for species to migrate, find food, and breed.

Moreover, roads can increase the spread of invasive species, alter local water cycles, and contribute to soil erosion.

True or false? Cattle ranching helps reduce deforestation by preserving large areas of the forest for grazing land.

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.

Brilliant work.

The reason why this statement is false is because cattle ranching is a major driver of deforestation, accounting for approximately 70% of deforestation globally.

Rather than preserving forest, large areas are cleared to create grazing land, contributing to habitat loss, soil erosion, and releases carbon dioxide.

Well done if you managed to explain that correctly.

I would like you to identify the cause of deforestation described.

Subsistence farmers burn areas of rainforest to make space to grow crops.

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

Fantastic, the answer is A, slash-and-burn.

Well done if you identified that correctly.

Which of the following countries has agriculture contributing to more than 60% of forest loss? Is it: A, Brazil.

B, Indonesia.

C, Peru.

D, Democratic Republic of Congo.

Or, E, Costa Rica? Pause the video here and press play when you're ready to continue.

Excellent, the answer is A, Brazil, and C, Peru.

Well done.

I would like you to look at the statement on your screen.

It says castle farming is the least destructive cause of deforestation.

I would like you, one, to place a cross on the line representing your opinion.

And two, justify your opinion and use evidence to support your opinion.

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

Fantastic, let's check our answers.

I asked you to place a cross on the line representing your opinion on the statement.

I placed my cross here, but your choice may be different from this one.

I then asked you to justify your opinion.

You might have written, "I strongly disagree with the statement that cattle farming is the least destructive cause of deforestation.

In fact, it is one of the most harmful causes of deforestation, and its impact is much worse than many other factors.

Cattle farming is responsible for around 50% of global deforestation, especially in places like the Amazon rainforest.

Large areas of forest are cleared to create space for cattle to graze, and this destroys vital habitats for wildlife.

Once trees are removed, the soil loses its nutrients, meaning that it becomes much harder for plants to grow back, forcing farmers to clear even more land over time.

This leads to a cycle of constant deforestation.

On top of this, cattle farming also contributes massively to climate change.

Not only does clearing forests release carbon dioxide into the atmosphere, but cows also produce methane, which is an even more harmful greenhouse gas.

While mining is a significant cause of deforestation, it does not have the same widespread impact as cattle farming.

Mining does destroy large areas of the forest and cause pollution, but affects a much smaller area compared to the vast stretches of land cleared for cattle ranching.

Mining is usually concentrated in specific regions, whereas cattle farming leads to deforestation on a much larger scale.

In conclusion, cattle farming is by far one of the most destructive causes of deforestation.

It causes long-term damage to the environment and contributes to global warming, making it far more harmful than causes like mining." Well done on this task.

You've done brilliantly.

I hope you managed to include some of those points in your answers, and you managed to include a conclusion at the end.

Fantastic, we've now come to the end of our learning in the lesson "Deforestation in the Tropical Rainforest." You've done brilliantly.

Before this lesson ends, let's summarise everything that we've learned today.

Deforestation is a process of clearing forests for other land uses such as agriculture, mining, urban development, or logging.

The widespread destruction of forests is harmful to ecosystems, leading to the loss of biodiversity and is destruction of vital ecological functions.

As trees are cut down, the carbon dioxide stored in them is released, contributing significantly to climate change.

In recent years, deforestation rates have remained high, particularly in tropical regions like the Amazon Rainforest, despite ongoing efforts to reduce these.

The main cause of deforestation includes agriculture, particularly cattle ranching, mining, and the construction of hydroelectric dams and logging for timber.

All of these activities contribute to forest loss and the degradation of vital ecosystems. Cattle ranching alone is responsible for approximately 50% of global deforestation as vast areas of the forest are cleared for grazing land.

Mining and dam construction also require large tracks of land to be cleared, often leaving behind long time environmental damage once the resources are extracted.

Logging both legal and illegal remove valuable timber from forests further exacerbating deforestation.

The impact of deforestation is severe.

Wildlife loses its natural habitats leading to a decline in species population and even extinction.

The loss of forest also disrupts the water cycle, affecting rainfall patterns and local water supplies.

Additionally, deforestation accelerates climate change as fewer trees remain to absorb carbon dioxide from the atmosphere.

In conclusion, deforestation is a critical environmental issue with far-reaching consequences, including the loss of biodiversity, disruption to ecosystems, and the worsening of climate change.

Despite efforts to reduce deforestation, it remains a major challenge that requires global cooperation and action.

Well done on today's lesson.

You've done brilliantly, and I look forward to learning with you again very soon.