Lesson video

Hello, my name is Mr. Marshall.

I'm here today to teach you all about the Gobi Desert.

So grab everything that you need for today's lesson, and let's get going.

By the end of today's lesson, you will be able to describe what the Gobi Desert is like, explain why it is growing in size, and give examples of action that is being taken to reduce this desertification.

There are five key terms for today's lesson, and those are "desert," "monsoon," "desertification," "climate change," and "erosion." "Desert" refers to an area of land that is extremely dry and receives less than 25 centimetres of rain per year.

"Monsoon" refers to a seasonal change in wind direction that brings a very rainy season or a very dry season.

"Desertification" is the process by which semi-arid land becomes drier and turns into desert.

"Climate change" refers to a large-scale and long-term change in the planet's climate, including weather patterns and average temperatures.

"Erosion" refers to the process of Earth's surface, for example, rock or soil being worn away and transported from its original site.

There are two learning cycles for today's lesson.

I'm gonna start with learning cycle 1, which is what and where is the Gobi Desert? Now, the Gobi Desert is an extremely large desert, and actually it covers parts of northern China and southern Mongolia, as if to give you a real glimpse into just how big it is.

So the Gobi Desert is the largest desert in the entirety of Asia and one of the largest deserts in the world.

As Aisha says, it covers an area of 1.

3 million kilometres squared, and that's actually five times the size of the UK.

So once again, you get a real sense of its large extent.

Now, deserts are areas of land where there is little or no rainfall.

And actually, if we divert our attention to the map in front of you and we look at the yellow colour, which is showing us the deserts, they can actually be found on each and every single continent around the world.

Now, deserts can be hot and they can be cold depending on their location.

In fact, Antarctica is an example of a cold desert.

What about Gobi Desert then? Well, the Gobi Desert is also a cold desert because of its northerly location and high altitude but it still has some very high summer temperatures.

It is situated on a plateau around 910 to 1,520 metres above sea level.

So it has a very high altitude.

Time now for a learning check.

And it says that Sam and Lucas are having a conversation about deserts, and who is correct? Sam says, "Deserts can be both hot and cold." Lucas says, "Deserts are only found in very hot climates." What you need to do then right now is pause the video whilst you consider as to who is correct.

And the correct answer was Sam.

Now remember, yes, deserts can be both hot and cold.

Deserts are defined by their extremely low rainfall, less than 25 centimetres of rainfall per year, so their temperature can be either hot or cold.

For example, Antarctica is what's known as a cold desert, and so too is the Gobi Desert as well.

So really, really well done if you're able to identify Sam as the correct answer.

Now, deserts are formed in a variety of different ways, and the Gobi Desert is an example of a desert which has been formed from the effect of a rain shadow.

Let me explain what that's all about.

So first of all, most of China has a monsoon climate.

In the summer, monsoon winds bring moisture from the Indian Ocean in the southwest and cause rain over much of China and most of south Asia.

Let's have a look at that map that you can see on the screen in front of you, and you can see those strong winds blowing up from the southwest, from the Indian Ocean.

Now what happens is this string of mountains, known as the Himalayas, blocks those monsoon winds, and as a result, it creates a rain shadow where there is very little rainfall.

So the rain is dumped in front of those Himalayan mountains, and as a result, that area is extremely wet as well as parts of south Asia and other parts of China to the east of those mountains.

However, the area behind the Himalayan mountains is extremely dry, and this is why we find the Gobi Desert there, because it is formed by a rain shadow.

So monsoon winds also bring moisture from the Pacific Ocean during the summer months.

The Gobi Desert is located a long, long way away from the Pacific Ocean, and so receives very little of its rainfall.

Once again, let's have a look at that map right there, and we can see those strong winds coming from the Pacific Ocean in the southeast.

And once again, we can see the huge distance it is that the Gobi Desert is from the Pacific Ocean, and so therefore it doesn't receive any or much of that moisture.

Places further inland then are usually drier than those at or near the coast.

And when we start looking at the climate of town, cities, and regions nearer the sea, we see that it is a lot more moist when compared with, for example, the Gobi Desert and other inland regions.

So temperatures in the Gobi Desert vary a lot during the year.

Temperatures can reach more than 40 degrees Celsius in the summer but also fall to -40 degrees Celsius in the winter.

There can be snow on higher ground during colder months.

We are looking at a desert with a vast range of temperatures, perhaps even as large as 80 degrees Celsius between summer and winter.

These extreme temperature variations and lack of rainfall make the Gobi Desert a really, really challenging environment for animals, people, and plants to live in.

So this is climate graph in front of you of an area called Dunhuang, and it's a city on the edge of the Gobi Desert in northwestern China.

Let's have a look at it now.

So we can see if we follow that line graph, because the line graph is showing us temperature, we can see that temperatures are high in the summer.

Let's have a look at that on the graph, and we can see that the temperatures are highest between May and September.

But we can also see that they are below freezing in the winter.

Again, let's have a look at January and February as well as December, and we can see that that line graph dips below zero degrees.

Dunhuang receives less than 40 millimetres of rainfall each and every year.

Again, we can look at that on the climate graph by looking at the bar chart now.

And if we total up all those different bars, we can see that it adds up to less than 40 millimetres of rainfall each and every year.

And this is what classifies this area as a desert.

Remember, a desert is classified as an area with less than 250 millimetres of rainfall.

The northwest of England receives around 1,400 millimetres of rainfall each year, so you really get a sense of just how dry Dunhuang actually is.

So a quick learning check.

It says, "True or false? Temperatures in the Gobi Desert are very hot all year round." What you need to do then is pause the video whilst you consider, and then select your answer.

And the correct answer was false.

Now, once again, I'd like you to pause the video here whilst you consider as to why or how the statement is false.

What should the true statement be? And the answer was, "Temperatures in the Gobi Desert can be very hot during the summer but fall to well below freezing during the winter months." So really, really well done if you're able to get those two answers correct.

Now, perhaps surprisingly, the Gobi Desert isn't covered in sand, as you would normally expect from a desert.

Most of the Gobi Desert is actually covered in bare rock, as the image in front of you does a great job in illustrating.

As a result, very few plants can grow in this harsh climate of poor soil quality and really extreme climate as well.

Little vegetation, by which I mean plant life and water, means that not many animals can survive in the desert either.

Animals that live here are especially evolved to deal with the climate and the conditions found there.

And these are animals such as camels, gazelles, and snow leopards.

Few people are also able to live in the desert, in the Gobi Desert, and as a result, it is very sparsely populated, by which I mean not many people live there.

And the population density, though, is beginning to increase.

Many of the people living there are nomadic herders, moving around from one area to the next, looking for new areas for their livestock, by which I mean their cattle or their sheep or their goats to graze.

And as Izzy says, "The word 'Gobi' means 'waterless place' in Mongolian." Remember, the Gobi Desert is not just found in China, it is also found in the neighbouring country of Mongolia, in the southern part of Mongolia.

So the Gobi Desert experiences regular dust and sandstorms, particularly in the springtime.

That satellite imagery you can see in front of you is doing an excellent job in showing you the powerful winds and the desert storms that you find across the Gobi Desert.

So sand and dust from the Gobi Desert can be carried thousands of kilometres by the wind, and this does actually cause air pollution far away in some parts of China, including major, major cities such as the capital city of China, Beijing, and Shanghai as well, a really major city on the east coast of China.

Now, winter storms are also a common feature in the Gobi Desert, and these winter storms are called dzuds.

It's a Mongolian term, and it essentially refers to or means severe winter conditions.

They are accompanied by freezing temperatures, snowfall, and frozen ground.

The ground freezes, which means that farmers can't plant the land and animals can't graze.

So you really begin to get a sense of just how difficult the conditions are in the Gobi Desert, when we look at their extreme summer as well as their extreme winter climate and conditions for plants, animals, and people.

So another learning check.

And it says, "Which of the following statements correctly describe the Gobi Desert?" I need you to select two answers.

So pause the video here, read through the four options, and select what you consider to be the two correct answers.

Best of luck.

And the two correct answers were A and C.

So it is a cold desert, and C, it is located at a high altitude.

Remember, it is found a long way above sea level, between 900 and 1,200 metres above sea level.

So really, really well done if you're able to select those two correct answers.

So we're now to our two practise questions for the first learning cycle.

And the first question says, "Mark the location of the Gobi Desert on the map in front of you." And the second question says, "Explain what the Gobi Desert is like and why it is a challenging environment." So what I'd like you to do then now is pause the video whilst you attempt these two practise questions.

Best of luck.

And in terms of feedback then, well, first of all, let's have a look at the map.

And this is where the Gobi Desert is located and where it should have been marked on your map.

You can see that it crosses both the northern part of China as well as the southern part of Mongolia.

Really, really well done if you are able to identify the Gobi Desert on your map.

In terms of the second question, this is the feedback your answer may have included.

I've said that the Gobi Desert is a cold desert located in a high altitude plateau in northern China and southern Mongolia.

It receives very little rainfall during the year because it lies in the rain shadow of the Himalayas.

There are a wide ranges of temperature in the desert.

Temperatures can reach more than 40 degrees Celsius in the summer and fall well below freezing in the winter.

The Gobi Desert also regularly experiences sand, dust, and winter storms. All of these factors make the Gobi Desert a very challenging environment.

So really, really well done if you're able to include anything like that in your own answer.

We're down to our second and final learning cycle, and this is all to do with why is the Gobi Desert actually growing in size? Now, "desertification" is used to describe the process of land turning into desert.

It often happens in the areas around existing deserts where the land is already less fertile and fairly dry.

So desertification is causing the Gobi Desert to rapidly increase and expand in size, and it's beginning to grow southwards across China.

And this is causing massive problems for both the people and the environment.

As Aisha says, around 27% of China's land area is covered in desert, and this area is, in fact, increasing in size.

There are six key reasons why the Gobi Desert is growing due to desertification.

Let's have a look at those right now.

So the first is deforestation.

This is the removal of vegetation.

Overgrazing by farm animals.

So agriculture, perhaps the intensive farming of crops.

Mining.

Rising population density as more and more people are perhaps moving into semi-arid areas bordering a Gobi Desert.

And finally, climate change, which is causing our climate patterns to change drastically.

We are now gonna spend a little bit of time looking at each and every one of these causes.

Now, people have lived in the Gobi Desert for thousands of years.

But with an increasing global population as well as an increasing population in China, population density in the Gobi Desert has risen in recent years, and this is causing environmental problems. Because with more people living in an area, it means that the resources are used up much faster and more of those resources are being used.

So limited resources such as wood and water are all being consumed by this growing population.

More land is also being used for human activities such as mining and agriculture, which also depletes water supplies.

We should remember that China's economy is really growing over the past 30, 40, 50 years, and therefore human activities in areas which were once not explored are beginning now to be exploited.

So as Lucas says, the Gobi Desert is a rich source of coal, copper, and other minerals.

And China, just like many other countries around the world in terms of their natural resources, are trying now to exploit those natural resources.

Because they can sell those on the open market, they can make money, they can use those goods or resources to actually produce other materials and products as well, which, again, can be used to create money, income, jobs, et cetera.

Human activities such as mine and deforestation and overgrazing result in the loss of vegetation cover, as the image in front of you does a great job in actually illustrating.

But how does this happen? Well, first, bear and dry soil is much more vulnerable to erosion by both wind and water.

And as we know already, the Gobi Desert can experience some very high strong winds.

Remember as well that, without plant life, there are no roots holding that soil together.

So by removing that vegetation, by perhaps deforestation or overgrazing, we're actually removing the ability to hold that soil together, and therefore the soil is much more vulnerable to being washed away perhaps by rainfall or being blown away by strong winds.

As a result, over time, the land becomes less fertile, as nutrients and soil is washed away or blown away, and therefore fewer plants can grow as a result.

It is therefore more difficult for plants, animals, and people to live there as a result.

Now climate change is a massive cause of desertification, and climate change really does affect the temperatures and rainfall patterns all around the globe.

Droughts, which means long periods without rainfall, are becoming more frequent and long lasting.

So dry areas are becoming drier with less rainfall, higher temperatures, and those semi-arid areas, which once boarded the Gobi Desert are now becoming desertified, turning into desert areas.

Now, because of desertification, as the Gobi Desert grows, sandstorms are happening more and more often and becoming more severe.

So when strong wind hits, then it picks up that sand and dust, and it creates a huge amount of material which is blown across very, very large distances.

This sand and dusk can have devastating impacts on human health, agriculture, and industry.

The image in front of you is a well-known example.

It does a great job in illustrating what I've just described there.

It's a dust storm in Beijing.

Now, Beijing is the capital city of China, and it lies over 1,000 kilometres away from the Gobi Desert.

So we can see then the devastating impact that strong winds in an area over 1,000 kilometres away can have on people living in a capital city like China.

It's a time there for a learning check.

And it says to complete the text.

Now, you've got three gaps there in that paragraph.

What I need you to do then is pause the video here whilst you read through that short paragraph and try your best to complete the three gaps.

Best of luck.

And the correct answers were, "Human activities such as agriculture, mining, deforestation, and overgrazing use water and result in the loss of vegetation cover.

Bare and dry soil is more vulnerable to erosion by wind and water." So really, really well done if you're able to get those three answers correct.

To try to combat desertification, China is implementing a number of different strategies to try and slow down the expansion of the Gobi Desert.

Now this is known as China's "Great Green Wall" afforestation programme.

And you can see the effect on the right hand side through that moving map.

Now, "afforestation" just refers to the planting of trees.

"Deforestation" refers to cutting down trees.

"Afforestation" refers to the planting of trees.

Now, in 1978, the Chinese government recognised the problem and started a project to plant billions of trees along the southern border of the desert.

The aim is that the Great Green Wall of trees will actually help to slow and reduce desertification.

Trees also have the added benefit of absorbing carbon dioxide from the atmosphere, which also helps in tackling climate change.

So it's really dealing with two massive problems in one.

The project is due to be completed by 2050, by which time the wall of trees will actually stretch for almost 5,000 kilometres.

So you can really see how China is taking a proactive step to the problem of both climate change and desertification through this enormous project of theirs.

But China hasn't stopped there.

It's also trying other different strategies to reduce and slow down desertification.

Strategies to use and store water more efficiently, to try to manage numbers of livestock to reduce overgrazing and thereby reduce the amount of vegetation removal, and finally trying to grow more drought-resistant crops.

Now, taking action against climate change can also help to combat desertification.

So really again, it's a solution which is trying to solve two problems in one.

So time now for a learning check.

And it says, "What is the Great Green Wall of China?" What you need to do right now then is pause the video whilst you try to recall that piece of information and give what you think is the correct answer.

And the correct answer was as Sam says.

She says, "A project by the Chinese government to plant billions of trees along the southern border of the Gobi Desert to try and reduce desertification." Really, really well done if your answer matched Sam's.

So we're on now to our two final practise questions for our final learning cycle.

And the first one says to explain how human activities are causing the Gobi Desert to increase in size.

And the second question says, "Describe one way in which people are taking action to help reduce this desertification." So what you need to do then right now is pause the video whilst you attempt these two practise questions.

Best of luck.

And now for some feedback.

So the feedback for the first question.

Your answer may have included something like this.

It says, "Human activity such as agriculture, mining, deforestation, and overgrazing use water and result in the loss of vegetation cover.

Bare and dry soil is more vulnerable to erosion by wind and water.

This causes the land to change into desert.

This process is called desertification." And now the answer for the second.

And again, your answer may have included something like this.

"One way in which the Chinese government is taking action is by planting billions of trees to create a wall across the southern border of the Gobi Desert.

The aim is that these trees will also help to reduce desertification as well as absorb carbon dioxide from the atmosphere, which also helps to tackle climate change." So really, really well done if you included anything like that in your own answer.

We're on now to our learning summary.

And what do you need to know from today's lesson? Well, the Gobi Desert is a large cold desert that covers parts of northern China and southern Mongolia.

The Gobi Desert is a rain shadow desert and is formed by the blocking of rainfall by the Himalayan mountains.

Different factors make the Gobi Desert a challenging environment to survive in.

Human activities are causing the Gobi Desert to increase in size.

But different actions are being taken to try and reduce desertification in and around the Gobi Desert.

So really, really well done during today's lesson.

It was a pleasure teaching you.

And I will see you again on the next lesson.

Goodbye.