Subtitles section Play video Print subtitles Hello, this is 6 Minute English from BBC Learning English. 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.