Gd 8 Climate Change Quiz review

Hello, my dear students. Welcome back. As-salamu alaykum. Today, we are going to be doing the climate change quiz review. Okay, so it's not going to be teaching session. It's going to be review of some questions, okay? If you would like more comprehensive explanation, please go back and watch the videos that we've recorded during the online teaching. For now though, this is going to be quick quiz review. All right? So, let's get ready and let's do it together. So, this is going to be the grade eight climate change quiz review. And for those of you who don't have your books for any reason, let's say you left it at school or you lost it, have taken the courtesy to put the book pages that you need for the test over here. Feel free take print of the screen or to study directly from it. So, you can pause the video and just study these pages. Let's just go through it. Here we go. So, they include the answers as well. There we go. And there you go. That's the last page. So, please feel free to pause these pages and read through them. Okay, so let's go through the questions. What is the main purpose of greenhouse effect on Earth? Okay, so the greenhouse effect is the effect obviously of trapping the the temperature due to greenhouse gases. So, the the main reason is to obviously warm up the planet so it can be good enough for for creatures to live, including plants, animals, and humans. So, it's not to block all the sunlight. It's not to make the Earth colder during the summer. it's not to help the moon stay in the orbit. It's to keep the planet warm enough for life, okay? Let's go to the next one. Which of these greenhouse gas mentioned in the text? Okay, so the text I've just shown you, which ones are examples of greenhouse gases? Methane certainly is. Methane CH4. You don't have to know the formula, but methane is definitely greenhouse gas. Another one is nitrogen oxide, not nitrogen on its own. we've got carbon dioxide as well, and we've got water vapor, H2O. That's also an example of greenhouse gas. But these ones on their own are not greenhouse gases. Let's go. What would happen if the earth to the earth if there were no greenhouse gases at all? Remember greenhouse gases are responsible for trapping the heat. And this heat is what helps creatures survive here on earth. So without it, there'd be no life here on earth. so what would happen if there was no greenhouse gases? There would be no change in temperature. There would be. The earth would be lot cooler. The planet would be too cold for life. Absolutely. The planet would be giant desert. no, the oceans well, it kind of would become giant desert in way because there would be no plants, nothing, but the oceans would boil away. No. So the the the proper answer here is that the planet would be too cold because there would be no greenhouse effect. There would be no trapping of heat. how do scientists use ice cores to study the climate of the past? Well, ice cores are these samples of ice that the the scientist take from ice that's been around for millions of years, so including the North Pole and the South Pole. And they have little tiny bits of bubbles and dust particles stuck in inside them. And if you look at those samples of air, the bubbles, you can analyze the atmosphere and see how much carbon dioxide was in it. You can see what kind of chemical composition it had, and so therefore where can find out what the climate was like. So, the main thing is to analyze the air particles and the dust trapped in the ice. When tree has grown rings that are very close together, what does it tell us about the climate change? So, obviously one way of figuring out the history of the climate is to look at the rings of trees. And when the rings are very close together, it means it was very cold and very dry. But when it's warm and wet, the rings are very far apart, which means it was like it had lot of water. so, when they're very close together, it's cold and dry. What short-term effect did the eruption of Mount Pinatubo have on Earth in 1991? Well, it doesn't matter what mountain it was. when there's an eruption, there's usually little bit of cooling. The reason why is because when volcanoes erupt, they have this big, huge cloud of ash and particulates that goes into the atmosphere, and this blocks the sunlight. So, sunlight cannot come in anymore, and sunlight is what makes the warmth here on Earth. So, without sunlight, you can bet that it's going to be cooler. And so, what happened was it caused the global temperature to drop by 1° Fahrenheit, which is the same as 1° Celsius. During an age an ice age, how much cooler was Earth's climate compared to today? So, remember Earth goes through an ice age approximately every 100,000 years, and during an ice age, the temperature is about 5 to 15° cooler. Okay? So, that's the answer there, 5 to 15°. What is the definition of global warming according to the text? It is the gradual increase of the Earth's temperature. That's what global warming is. Global means the world and warming means it just gets more and more and more. The temperature increases. Let's keep going. Which human activity is responsible for about 9% of greenhouse gas emissions in the United States? Well, in the United States it is agriculture and raising livestock. And what we mean by livestock here is cows, sheep, camels, yeah, horses, chicken, all of that. They release lot of methane gas cuz the bacteria in the guts, once they eat or feed on the remains of food, that's what's released. The gases that are released. And so, the same thing happens when things die. bacteria feeds on it and releases methane gas, which is greenhouse gas. Okay? Why does deforestation, cutting down trees, lead to more carbon dioxide in the atmosphere? Well, what do trees do? Trees are natural filters. Trees, what they do is they take carbon dioxide from the air, they trap it, they turn it into wood, and they turn it into glucose or sugar, okay? And so, once you burn that wood or you cut it down or you, you know, you get rid of the tree, essentially what you're doing is you are releasing carbon dioxide into the atmosphere. But if you're cutting the tree as well, you're also preventing carbon dioxide from being absorbed into the tree. So, not only are you releasing carbon dioxide by burning the tree, but you're also that's one way of like thinking about it, but also like just by cutting down the tree, you're preventing carbon dioxide from being absorbed. Trees are essentially filters of carbon dioxide. Okay? So, which one is it then? Cutting down trees makes the wind hotter? Uh-uh. Trees produce greenhouse gases when they are alive? Mm-mm. well, they do, but like it's very negligible. It's such small amount. Trees naturally absorb carbon dioxide for photosynthesis. Absolutely. Roots of trees release carbon dioxide when they grow. Mhm. Okay. Let's keep going. We're doing very well. What are fossil fuels such as coal and petroleum formed from? Fossil fuels are formed from the remains of ancient organisms. So, that includes plants, animals, and even maybe humans. Dinosaurs. Are animals. according to the CO2 concentration graph, what has happened since 1950? Well, it doesn't matter whether it says 1950 or 1940 or even 1900, the carbon dioxide levels have risen. They keep increasing and increasing and increasing. So, the level of carbon dioxide has risen far above historical norms. Absolutely. Okay. What is carbon footprint? We're doing very well. The carbon footprint is essentially the amount of greenhouse gases emitted through human activity. So, basically, if say, for example, I'm making car, and you ask, "What is the carbon footprint of the car? The how does the car have carbon footprint?" You see the amount of carbon dioxide released during the manufacturing of that car, during the making of that car, and during the usage of that car, the total amount is called the carbon footprint. Okay? When you are designing building, when you are making new invention, you got to think about that as an engineer. You got to think about that as an architect. You got to think about that as human being. When you are deciding on something to do, like project or whatever, you always think about what is the carbon footprint of that, right? So, this is something essential that we always have to think about is the amount of greenhouse gases emitted through human activity. which natural cycle can impact the climate by changing how much sunlight the Earth receives? Well, that is the Milankovitch cycle, which is the tilting of the Earth. So, variations in the Earth's tilt, which naturally happen with time. How do scientists use fossil fossils found in Antarctica to understand climate history? Remember, the fossils found in Antarctica can tell us about the history of Antarctica and the history of the climate. They use fossils to see if any dinosaurs like the snow. Fossils show that Antarctica has always been covered in ice. no. In fact, the opposite. they use fossils to build new islands in the ocean. That's just silly. Fossils of form where the plants suggest it was once warmer. Absolutely. So, what they found was there were lot of plants that don't exist in snow, but they exist in warm weather. Now, those fossils suggest that those plants were there because it was lot warmer back then. And that's the end of