Lesson video

Hello geographers.

My name's Mrs. Homagio, and I'm really looking forward to teaching you today.

I hope you're gonna enjoy the lesson and learn lots.

Let's get started.

Today's lesson is about weather hazards in the UK.

And by the end of the lesson, you will understand that the UK is affected by weather hazards and that there is evidence that weather is becoming more extreme within the UK.

There are three key words for today's lesson.

Weather, the day-to-day conditions of the atmosphere at a particular place.

For example, the temperature or the rainfall.

Climate, the average weather conditions of a place over a longer period of time.

And this is typically 30 years.

Extreme weather, when a weather event is significantly different from an average or usual weather pattern.

And this may take place during a day or over a longer period of time.

There are two parts to today's lesson.

The first one is what weather hazards affect the UK? And the second, are weather hazards becoming more common? Let's get started with the first.

A weather hazard is an extreme weather event that poses a risk to people, property, and the environment.

Can you think of any weather hazards? Have you experienced any weather hazards? You might want to pause the video now and have a quick discussion with the person next to you or your class.

An air mass is a large body of air with similar temperature and humidity throughout.

Weather hazards in the UK are affected by air masses.

And you can see here we have a map of the UK with the different air masses that are approaching from different directions.

The UK can be affected by several different air masses, which helps explain why the UK's weather can be so different from day to day.

Let's have a quick check.

True or false, extreme weather is weather that has never been experienced in a place before.

Is that true or false? Pause the video and have a think.

Did you say false? If so, correct.

But why? Pause the video and see if you can justify your decision.

You might have said something like extreme weather is weather that is significantly different from the average or usual weather for the time of year, but that doesn't mean it has never happened in that place before.

Can you think of six types of weather hazard the UK experiences? Pause a video and have a quick think.

Some of the ideas you might have come up with are strong winds, torrential rain, snowfall and ice, heat waves and droughts, and thunderstorms. We're going to look at each of these in a little bit more detail.

Firstly, strong winds.

So the UK frequently experiences strong winds, particularly in the winter, and these winds can lead to fallen trees, it can damage infrastructure, and it can cause widespread disruptions.

We've got an example of storm Ciaran in November in 2023.

Very, very strong winds, gusts reaching over 80 miles per hour.

Torrential rain.

Rainfall over a long period of time or shorter bursts of intense rainfall can lead to surface water, flash flooding, and river flooding.

And that flooding can cause big damages to homes, infrastructure, close roads, disrupt transport services, and potentially contaminate water supplies as well.

In October 2023, storm Babet brought intense rain which led to significant flooding in parts of Scotland and Northern England.

Snowfall and ice.

So the UK can experience heavy snowfall and icy conditions in winter.

And this is most common in the north and eastern regions of the UK, as that's where you get the polar and the Arctic air masses bringing the very cold air across to the UK.

This can lead to hazardous travel conditions, school and office closures, and it puts a real strain on emergency services as they try to get about and help people during these situations.

Some of you may remember the Beast from the East, which was in February and March of 2018, and it caused very, very heavy snowfall and freezing temperatures across the UK.

Heat waves and drought.

So extended periods of dry weather and very, very hot weather in the summer can cause problems. We might think we are enjoying it, but it can cause problems such as water shortages.

It can have an impact on agriculture and wildlife and people's health, particularly vulnerable people.

And for example, you may remember during the summer of 2022, parts of England experienced extreme temperatures.

Some areas reached around 40 degrees Celsius, and there was much less rainfall than normal, which led to drought conditions.

This heatwave actually shut some schools across the UK for a few days.

Thunderstorms. These can bring heavy rain, hail and lightning, and it can cause localised flooding and damage.

And there's an example in 2023 in August where parts of Southern England experience severe thunderstorms. Here's a check for you now.

What weather hazards affecting the UK are represented by these images? So think back over the ones we've discussed, and what do these images show? Pause the video and come back in a minute.

You might have said for the first one, snowfall and ice, the second one, heat waves and droughts, and the third one, torrential rainfall leading to flooding.

So your first task.

Complete this spider diagram identifying the main weather hazards the UK experiences.

So for each part of your spider diagram, include a brief summary of each hazard and the impacts it can have.

Here's an example for you.

Strong winds are frequently experienced during winter storms. It leads to fallen trees, damaged infrastructure, and widespread disruptions.

So pause the video and see if you can complete the further four examples of weather hazards in the UK.

So your answer may have included something similar to what you can see on my spider diagram.

Torrential rain.

Heavy or persistent rainfall can lead to flooding.

This can damage and disrupt infrastructure.

Snowfall and ice.

Heavy snow and icy conditions can lead to hazardous travel conditions and cause schools to close.

Heat waves and droughts.

Extended dry periods and extremely high temperatures can lead to water shortages which affect agriculture, wildlife, and people's health.

And thunderstorms bring in heavy rain, hail, and lightning.

And they can cause localised flooding and damage.

If yours look similar to this, well done, great job.

Let's move on now to the second part of the lesson.

Are weather hazards becoming more common? The State of the UK Climate report is published by the Met Office.

It's an annual publication, so it comes out each year, and it gives you an overview of indications of changes to the climate in the UK, and it reports on extreme weather events.

And you can see here this infographic gives us a few headline bits of information.

Let's have a look at it in a little bit more detail.

The 2023 State of the Climate report shows that the UK's weather has increasing extremes, and this is shown here.

2023 was the second warmest year on record in the UK.

The UK recorded its warmest June on record, and it had seven named storms with the most active start to the storm season.

And September to December in 2023 was the wettest period since 2000.

So we can see that that there 2023 is experiencing more extremes.

True or false for you then.

The State of the UK Climate report 2023 provides evidence that the UK's climate is changing.

True or false? Pause the video and make your decision.

Hopefully you said true, but why? Can you tell me why? Pause the video and come back when you've decided.

You might have said something similar to this.

Climate is the average conditions over a long period of time, and the report shows that average temperatures have increased.

And it may be that you've included an example.

I put 2023 had the warmest June, and 2014 to 2023 was 1.

25 degrees Celsius warmer than 1961 to 1990.

What do these choropleth maps tell us about the UK's rainfall? So a choropleth map uses a colour scale to represent data, and in this case, we have the colour blue on the scale to represent the number of very wet days experienced in the UK.

There are three maps because it is showing us three different time periods: 1961 to 1990, 1991 to 2020, and 2014 to 2023.

As we look at these maps, we can see that there is an increase in the number of very wet days experienced in the UK, and that is because there are more areas coloured darker blue in the time period 2014 to 2023 than there are on the previous two maps.

Let's have a look at these choropleth maps now telling us about the UK's temperature change.

Again, there are three maps for the three different time periods, and a coloured scale this time representing the number of days in the UK per year that are 28 degrees Celsius or higher.

These maps show us that there are an increasing number of days where temperatures exceed 28 degrees Celsius per year in the UK.

And we can see this because on the map for 2014 to 2023, there are more areas of the UK that are shaded the darker orange and red colours compared to the previous two maps.

2023 was another year of significant weather events.

Some facts for you now.

It was the second warmest year on record for the UK, it had the UK's record warmest June, and there was a September heat wave.

In terms of rainfall, it was the seventh wettest year on record.

March, July, October, and December were all top 10 wettest months on record.

And it also had the most active start to the storm naming season.

Let's have a bit of a check now then.

Which statements correctly describe what the State of the UK Climate report in 2023 evidences? A, average UK summer temperatures are increasing, B, number of extremely hot days in the UK is increasing, C, the UK average rainfall amounts are decreasing, and D, the number of extremely wet days shows no change.

Pause the video here, discuss the statements, and see which ones you think are correct.

Did you say A and B? If so, well done.

Average UK summer temperatures are increasing, and the number of extremely hot days in the UK is increasing.

Increasing emissions of greenhouse gases into the atmosphere due to human activity is causing temperatures to rise.

And we can see that on the graph to the right.

The temperatures are going up as there is an increase in concentration of greenhouse gases, and this is particularly evident from 1960 onwards.

Rising temperatures has an impact on weather hazards.

Scientists have observed that there is an increase in frequency and intensity of extreme weather.

This is a proportional bar chart to show the number of loss events taking place between 1980 and 2019.

Now some of these are not relevant to this lesson, for example, geophysical events, but some of these are.

The general trend of these loss events is that they are increasing.

If we focus on the meteorological events, so the green sections of the bar chart, and the climatological events, the yellow sections of the bar chart, we can see that over time, they are increasing in terms of the number of loss events.

So they are having a bigger impact across the world.

The jet stream and the Gulf Stream both influence weather in the Northern Hemisphere where the UK is found.

The jet stream is a powerful band of wind high in the atmosphere, and the Gulf Stream is an ocean current.

The position of the jet stream affects the weather experienced in the UK.

It acts a little bit like a boundary between air masses.

If it sits to the south of the UK, it is likely we will experience colder temperatures.

If it sits to the north of the UK, it's likely temperatures will be warmer.

If it sits over the UK, we are likely to experience wetter and windier weather.

The Gulf Stream makes UK winters milder and wetter than other parts of Northern Europe.

Global warming is changing the strength of the Gulf Stream and the jet stream, and one result of that is that weather systems may well remain over the UK for a longer period of time, and that's known as atmospheric blocking.

The impact of that is that there is a greater chance of extreme weather events taking place.

Quick check for you now.

What do these two images show, and how do they link to weather hazards becoming more common in the UK? For the first one, you may have said climate change leading to an increase in global temperatures, and the jet stream and Gulf Stream are weakening, making extreme weather more likely in the UK.

Final task now for today's lesson.

Two questions for you.

Number one, what evidence is there to show that the UK is experiencing more extreme weather? And because this is about the UK, you should refer to data evidencing changes specifically to the UK, and you might want to consider temperature and rainfall data.

Question number two, why is the UK experiencing more extreme weather events? Pause the video and see if you can find answers to these two questions.

Your answer to question number one may have looked something like this.

UK temperatures are showing an increase in extremes of temperature.

2014 to 2023 had a greater number of days of temperatures over 28 degrees Celsius, or 2023 was the second warmest on record, or UK rainfall is increasing.

2014 to 2023 had more days of exceptional rainfall than previously.

Question number two, why is the UK experiencing more extreme weather events? Your answer might have included something like this.

Climate change due to increased greenhouse gases is leading to an increase in global temperatures, global warming.

Scientists have linked this to an increase in the frequency and intensity of extreme weather.

The jet stream is changing due to global warming.

This can lead to atmospheric blocking over the UK, meaning that weather systems sit over the UK for extended periods of time, increasing the likelihood of extreme weather events.

Well done if you had answers that were similar to that.

Lots of learning taking place in today's lesson.

Let's have a little look at the summary.

So weather hazards are extreme weather events.

The UK experiences a range of weather hazards including thunderstorms, torrential rain, heat waves, and droughts.

There is evidence to show that extreme weather is increasing.

There are more days over 28 degrees Celsius recorded between 2014 to 2023 than previously.

Increasing frequency and intensity of extreme weather events in the UK and globally is related to global warming.

Global warming and its impact on the jet stream and Gulf Stream are affecting UK weather.

Well done today, I hope you have enjoyed the lesson, and I hope you now understand a little bit more about weather hazards in the UK.

I look forward to seeing you again soon.