Lesson video

Hello, again.

I'm Ms. Couves.

I'm so looking forward to teaching you today.

This unit is one of my favourites because it's all about saving our planet.

Our planet is such a special place filled with the most amazing wildlife.

I've been looking out to the window today to see all the wildlife in my garden.

There are butterflies and birds, and bees.

What can you see outside your window? Today, we are thinking about life cycle assessments.

A lifecycle assessment is what scientists use to assess the environmental impact of an item.

I am so excited for all the learning we're going to do today.

Let's get started.

So today, we are going to start off by recapping our knowledge on the things we have learned so far.

Then, we will learn what a lifecycle assessment is.

And then, we will compare takeaway coffee cups with reusable coffee cups.

And finally, we will evaluate which of the coffee cups is more environmentally friendly.

In this lesson, you will need an exercise book or paper, and a pencil.

If you don't have these things, pause the video now and go and get them.

First, let's recap what we already know.

What is a natural material? A natural material is a material that comes from a plant, an animal or the ground.

Can you remember the three examples? Cotton from plants, wool from an animal, and coal from the ground.

How much of this slide you can you remember? Pause the video and write down as much as you can.

A synthetic material is a material that is made by humans, including plastics, ceramics and glass.

Where do materials go that are thrown away? They go to landfill sites, where it takes them a really long time to break down.

The problems with landfill sites is that they produce harmful toxins and harmful pollutants.

Sustainability is about meeting the needs of people right now without sacrificing the ability of future generations to meet their needs too.

The three things that we can do to increase our sustainability is reduce, reuse and recycle.

So what is a lifecycle assessment? Coffee shops have started giving discounts for customers bringing their own cup.

As scientists, we need to work out if it's really better for the environment to bring your own cup.

If we think about this, we need to think about three things.

Firstly, how are the cups made? Secondly, how would the cups used? And thirdly, how are the cups disposed off? Pause the video and write down the three things scientists consider when they're making a life cycle assessment.

Let's compare our coffee cups.

To compare our coffee cups, we're going to look at five things and make a judgement on each one.

At the end, we're going to write an evaluation.

So it is as important that we make excellent list in our table.

Pause the video now and draw your table.

Press play when you're ready to continue.

This is my reusable coffee cup.

I want to know this reusable coffee cup is better than just using a paper cup very time I go for a coffee.

To do that, I need to think about the raw materials, the amount of material required to make the cup, whether it can be reused, whether it can biodegrade, and whether it can be recycled.

Lastly, if we think about our raw materials, the raw materials used to make my plastic travel mug, is crude oil.

Crude oil is a finite resource, and it's likely to run out soon.

The coated paper cup, the raw material is wood.

Wood is non-renewable, however, it's quicker to make a tree than it is to make crude oil.

So it is likely to run out eventually, but not as quickly as crude oil.

If we think about the travel mug and the paper cup, just in terms of the raw materials, which one is more environmentally friendly? Well, the crude oil is going to run out soon, but the wood will run out eventually.

So it is more sustainable to use the wood than it is to use the crude oil.

So if just in terms of the raw materials, it seems like the paper cup is better.

Pause the video and write down any notes in your table.

Now, pause the video and write your judgement about whether the paper cup or the reusable cup is better in terms of the raw materials.

Next, we're going to think about the amounts of material required.

To make my reusable cup, I need quite a lot of material.

It's quite heavy, there's quite a lot of material used.

The paper cup is much lighter and much less material is used.

Therefore, the raw materials are used up faster to make the travel mug than to make the paper cup if we were to make the same amount of each cup.

Pause the video and make any notes in your table.

Now I want you to think about your judgement.

If you compare the reusable travel mug with the coated paper cup, in terms of the raw material, how quickly the raw materials are used up, which one do you think is better? Pause the video now and write down your judgement.

Now we're going to think about whether it can be reused.

Well, I can reuse my travel mug, I use my travel mug every day, which means I don't have to use as many paper cups.

If I was using a paper cup every day, I would use 365 cups in a day, in a year whereas I just use the one cup.

So, if I can reuse it multiple times in its lifetime, less cups need to be produced and disposed off.

Scientists believe that a cup needs to be reused 20 times to make it more environmentally friendly than a paper cup.

That's a really useful fact, let's remember that one for later.

How many times does a cup, let me try again, how many times does a cup needs to be reused in order to make it more environmentally friendly than a paper cup? It needs to be reused 20 times.

Pause the video and make any notes in your table now.

Now, pause the video and write down your judgement.

Next, we need to think about what happens to the cup when we throw it away.

If the cup is biodegradable, it can be broken down by the environment.

If it's not biodegradable, it will exist for a really long time in landfill, like our plastic bottles.

Our reusable travel mug cannot be broken down naturally, and so it will exist for a very long time in landfill.

Our paper cup can be broken down naturally, so it's much, sorry, will exist for a short time in landfill.

The reusable travel mug will exist for a long time in landfill whereas the paper cup only will only exist for a short amount of time.

Pause the video and write down any notes in your table.

Thinking about that amount of time that the mug will spend in landfill, which one do you think is better for the environment? Pause the video now and write your judgement in your table.

The final thing that we need to think about is whether or not we can recycle the travel mug.

If we can recycle the mug, it doesn't go into landfill because it gets turned into another useful product.

My travel mug can be recycled into another useful material, so it is less likely to end up in landfill.

The paper cup, because it has a very thin plastic coating on the inside, can not be recycled into another useful material, so will end up in landfill.

Pause the video now and write down any notes in your table.

If the mug is recyclable, does that make it better or worse for the environment? Pause the video and write down a judgement in your table.

Now we've got lots of knowledge about our travel mug versus our paper mug, we are going to try evaluating our coffee cups.

That means, we're going to decide based on all the evidence that we have, which one is better.

And you're going to be able to tell people, "I think you should use this type of mug because.

." To help us with this, we're going to use this table.

Pause the video and draw this table into your notes.

Press play when you're ready to continue.

So firstly, let's think about the coated paper cups.

Why are the coated paper cups better? Well, I might say that they're better because they use more renewable resource, so it will take longer for the resource to run out, that makes it more sustainable.

Write down all the reasons you can think of in the first box.

Pause the video so that you can write them down.

Press play when you're ready to continue.

Now we're going to think about why travel mugs are better.

Well, I might say that travel mugs are better because you can reuse them.

In fact, I know that scientists say that the travel mugs are better for the environment if you use them more than 20 times.

If you reuse an item, it means you have to make less of them, that means we save all our natural resources, and we don't throw as much away.

Pause the video and write down all the reasons you can think of in the second box.

Press play when you're ready to continue.

Now, now we have all our evidence that paper cups are better and all our evidence that travel mugs are better, we need to decide which one's better.

Do we think that paper cups are better? Or do we think that travel mugs are better? What do you think? Why do you think that? Okay.

Now, you're going to turn that into a justification.

So you're going to say, "Overall, I think that is better because.

." And then you're going to give a reason.

It's really important as a scientist that you give a reason why when you're saying something is better, and that that reason comes from the evidence that you've looked at.

All the evidence you have is already in your table.

Okay.

I think we're ready to start writing.

I'd like you to pause the video and write your evaluation in full sentences.

Remember to use your planning table to help you.

Press play when you're ready to continue.

Our big question for today is related to our lifecycle assessment.

It is, should we be angry when people use cups that can only be used once? Have about think about your evaluation.

Do you think coffee shops should insist that everyone uses a reusable cup? Discuss your thoughts with your friends and family.

Well done on an excellent lesson today.

That evaluation was really complicated, but you did a great job.

Make sure you have a go at the quiz at the end to check how much you've learned.

See you next time.