I'm Neil.

And I'm Sam.

'No one is too small to make a difference'.

Do you know who said that, Sam?

Wasn't it climate change activist Greta Thunburg?

That's right! She went on to say  this in her message to world leaders.

'I don't want you to be hopeful.

I want you to act as if your house is on fire, because it is.'

Her speech reflected the feelings of many young people around the world who

think that not enough action is being taken on climate change.

And they might be right, judging by the record-breaking temperatures that hit

Canada and the north-west of the United States in July this year.

Greta Thunberg's plea to 'act like your house is on fire' became a reality for

residents of the small town of Lytton, Canada, which burned to the ground in

a shocking wildfire - a fire that is burning strongly and out of control.

So, was the Lytton wildfire yet another climate change wake-up call?

A wake-up call is the expression used to describe a shocking event that should

make people realise that action is needed to change something.

Maybe not, according to some climatologists who, worryingly, say that what happened in

Lytton should not even have been possible. So, in this programme, we'll be

asking if scientists have dangerously misunderstood the realities of climate change.

But first it's time for my quiz question

and it's about that extreme weather in Canada. It broke records when the

temperature in Lytton hit an all-time high on the 1st of July but just how

hot did it get? Was it

a) 39.6 degrees,

b) 49.6 degrees or c) 59.6 degrees Celsius?

All those temperatures look really  high, especially for snowy Canada!  

I'll say a) 39.6 degrees C.

OK Sam, we'll find out the answer later on.

Seeing your hometown burned  to the ground is bad enough,

but perhaps even worse, was the fact  that the wildfires were so unexpected.

According to weather pattern modelling done  by a team of Oxford University researchers,

such extreme heat was  impossible, in theory at least.

The research team was led by  climatologist Geert Jan van Oldenborgh.

Here he is in conversation with BBC World  Service programme, Science in Action.

This is a wake-up call beyond the  wake-up calls that we've had before.

Yes, it's a very big shock  in the sense that we thought  

we knew that how heat waves  react to global warming

and within which boundaries they 

are increasing. Of course  they're increasing in temperature

but it's a gradual process, we  thought. And then you get this thing  

and it's not gradual at all, it's a huge jump.

Professor van Oldenborgh had been studying the impact of global warming on

heatwaves - short periods of time when the weather is much hotter than usual.

Along with other climatologists, he thought that climate change was gradual

- changing or happening slowly over a long period of time.

But the Canadian heatwaves  caused him to think again.

Instead of being gradual, the temperature saw

a jump - or a sudden increase - of five degrees

and it's this sudden jump that's got Professor van Oldenborgh and his team worried.

By collecting data from all over the world, climatologists tried to

predict changes in the pattern of global warming.

But as Geert Jan van Oldenborgh told BBC World Service's Science in Action, the

heatwave in Lytton, didn't fit these predictions at all.

Everything looked like a nice, regular, gradual trend like we're used to up to

last year, and then you suddenly break all your

records by four or five degrees. I mean, this is something that's not supposed to

happen, and it has really shaken our confidence in how well we understand the

effect of climate change on heatwaves.

Despite all his research, Professor van Oldenborgh

is still unable to explain such extreme

and sudden changes in the

climate. And this, he says, has

shaken his confidence - made him

doubt something that

he was certain was true.

And it's this lack of understanding worrying

researchers because, as the story of the

town of Lytton shows, the

effects of climate change may be even worse than expected.

Maybe it's time we all took notice of Greta Thunberg's wake-up call to take

action on climate change.

Especially if even cold,  northern countries like Canada,

or Britain, for that matter, can  experience such extreme changes.

Speaking of which Neil, what was  the answer to your quiz question?

Ah yes! In my quiz question, I asked you  exactly how high the temperature reached

in the Canadian town of Lytton. What did you say, Sam?

I thought it was a) 39.6  degrees Celsius. Was I right?

Well, you were close but,  in fact, it got even hotter,

actually reaching 49.6 degrees Celsius,

the highest temperature ever recorded in Canada by at least 5 degrees.

Phew, that is hot! Ugh well, we'd better recap the vocabulary

from this programme, because we might

be hearing these words a lot more in the future.

Let's start with a wildfire, which is an

out-of-control fire that  is burning the countryside.

A wake-up call is an event which should make people realise that action needs to

be taken to change a situation.

A heatwave is a period of days or weeks when

the weather is much hotter than usual.

A jump is a sudden increase.

Whereas gradual means happening slowly over a long time.

And finally if something shakes your confidence

it makes you doubt something that you

thought was true.

That's it for our look at one  of the hottest years on record.

Bye for now.

Bye!

Hello. This is 6 Minute English  from BBC Learning English. I’m Neil.

And I’m Sam.

These days, our lives are filled with

devices that were unimaginable  only a few years ago

– the sorts of things you read  about in science-fiction novels,

but never thought you’d own.

Yes, like those robots that vacuum  your floor or voice-activated lights

– we call many of these things ‘smart tech’.

But while they can help with  the little tasks at home,

some people are wondering whether  they can help fight climate change.

Yes, smart homes, regulating things like the  temperature, are a step in the right direction.

Using AI to learn when the house is occupied  and the optimal time to fire up the heating,

is one way to limit wasteful use of resources.

The problem comes from the origin of the  energy which powers these home systems.

If it’s fossil fuels, then  digging them up – an informal way

of saying removing something from the earth

- and burning them creates carbon emissions.

I suppose that’s why many people are trying  to find more renewable forms of energy

to reduce their carbon footprint.

Well, it’s interesting that  you mentioned carbon footprint,  

because my question is about that today.

How many tonnes of carbon dioxide  are humans responsible for emitting  

into the atmosphere every year?

Is it more than: a) 30 billion; b) 40 billion; or c) 50 billion?

Well, Neil, that all sounds like a lot to me,

but I’ll go straight down the middle and say

b) 40 billion tonnes.

OK, Sam, we’ll find out the correct  answer at the end of the programme.

So, you mentioned earlier that people are  looking into ways to use more renewable energy,

but there are also some problems  with that form of energy production.

Yes – for example, many of these technologies  rely on certain weather conditions,

which affect the levels of energy production.

Dr Enass Abo-Hamed, CEO of H2go,  is working on a project on Orkney,

an island off the coast of Scotland, testing  ways of storing renewable forms of energy.

Here she is on the BBC World Service programme  Crowd Science, speaking with Graihagh Jackson,

talking about the limitations  of renewable energy sources.

Renewable energy is intermittent by its nature  because it’s dependant and relying on the weather.

When the Sun shines and when the wind blows,  

and these by nature are not  24-hour 7 reliable constant.

And that means that demand doesn’t always  meet supply of renewables – it can mean

that we get blackouts, but  on the other hand, it means

that when the Sun is up and we  are producing all that power or  

when the wind is blowing and were producing power,

we might not be able to use that energy -  there’s no demand for it - and so it’s wasted.

So, Dr Enass Abo-Hamed said the  renewable energy is intermittent,

which means that something is not  continuous or has many breaks.

She also said that because there isn’t  always a steady stream of energy,

we can get blackouts – periods  of time without energy.

People like Dr Enass Abo-Hamed are trying to find  solutions to make renewable energy storage devices

– which would make the supply  of energy more constant.

Smart tech can also help with this  problem with renewable sources.

Now, of course, not only can  computers be used to design

efficient models, but smart tech can also be

used to improve performance

after things like wind  turbines have been installed.

Here is Graihagh Jackson, science  broadcaster and podcaster,

speaking about how smart  tech can improve efficiency

on BBC World Service programme, Crowd Science:

Some engineers use something called a digital  twin. This is really interesting, actually.

This is where lots of sensors  are attached to the wind turbine,

so it can be modelled on a  computer in real time. And then,

using machine learning, you can  then simulate what’s happening

to the wind turbine in specific  weather conditions. And

this is important because it means they can  make sure they’re performing their best.

Graihagh Jackson used the  expression 'in real time', which means

without delay or live.

And she also mentioned machine learning,

which is the way computers change their  behaviour based on data they collected.