Middle school Earth and space science - NGSS
Earth's temperature and weather patterns have changed rapidly over the past century. This process, known as climate change, is caused mainly by human activities, especially CO₂ emissions. To avoid the worst impacts of climate change, we need to both reduce emissions and remove excess CO₂ from the atmosphere. Created by Khan Academy.
Want to join the conversation?
- Did you know that if the temperature of earth rose by 3° C then the crops would die out, if the temperature rose by 8° then all of the animals on earth would go extinct.
Even though these rises doesn't look like much, but they can be deadly. Right now scientists are trying to invent a new kind of car, Fuel Cell Car, it runs on Hydrogen and its exhaust is water vapor instead of Carbon dioxide. These kind of cars rely on electricity to combust the hydrogen and same as a car running on oil it goes *BOOM!!* than the car propels forward. The problem of this is there are almost no hydrogen refill stations, plus hydrogen is a rare kind of gas on earth. There another kind of car that runs on Ethanol a kind of oil that comes from plants like peanuts, corn, sunflower. The carbon dioxide they make is less than normal oil that the cars right now make. Scientists are trying to make Ethanol out of non-consumable parts of the plant like the leaves on the corn not its seeds.(7 votes)
- Why do many people say global warming is a hoax?(0 votes)
- Some people think that, instead of global warming, the Earth is going through cycles of warmth and cold (which is based in truth), because during the age of the dinosaurs, the earth was much hotter than it is today.following the age of the dinosaurs, the earth's temperature started tofall, culminating in the ice age. Since then, temperatures have risen, so people think today's rising temperatures are because the earth is entering another warm cycle.(6 votes)
- how did the wolly mamouths die(1 vote)
- Woolly mammoths became extinct largely due to climate change. Most woolly mammoths went extinct for the same reasons that most other megafauna went extinct 10,000 years ago. A combination of over-predation and climate change most likely killed off woolly mammoths.(5 votes)
- Are Anaerobic digesters the answer to global warming.(2 votes)
- while we are on a kinda deep topic, what does everyone think will happen after we die? (honest question, I know what I belive but I wanna hear about everyone else)(2 votes)
- HOw come the greenhouse gases can get in but cant get out. If something can get in it should able to get out? RIght??(1 vote)
- The greenhouse gases come from natural and manmade processes on Earth. The greenhouse gases absorb energy, which traps the energy in the atmosphere. As more greenhouse gases are produced more energy is trapped.(3 votes)
- now im not saying that climate change isnt real but we are still technically in a ice age because the polar caps are not fully melted yet so we can expect for those to melt but human activity is speeding up the process. although because of this "ice age" that we are in I feel as though people who blame climate change for the polar caps melting dont know that the caps are also melting naturally. so I guess what im saying is that people dont know the whole story. next time you hear something you dont know fully about do some research(1 vote)
- To educate those who look inside of the comment section this is partially wrong. The reason earth is heating up faster than usual is because of natural cycle of temperature ages. The ice ages? One of those. The dinosaurs? Very warm and humid. Its just a natural cycle. Almost all of the blame is being put on industry when actually most of it is from the planet. Some of it is from Co2 but almost all of it is just a cycle.(1 vote)
- [Narrator] Have you ever tried to imagine what the world was like in the distant past? Maybe you'd like to explore the age of the dinosaurs when the earth was much hotter than it was today. Perhaps you'd prefer when temperatures dropped too much colder than today. You could track a mammoth alongside our early ancestors who evolved around the end of the last ice age. We know about all of these ancient climate trends because scientists learned how to estimate them using evidence from ice cores, tree rings, and other natural phenomena. We now know that for most of human history, people could expect a pattern that looks something like this graph from the National Aeronautics and Space Administration which shows how temperatures changed each year in comparison to this line, which represents the average global annual temperature from 1880 to 1899. When we look at the time period between 1880 and 1940, we can see that some years temperatures would be higher than this average, some years they would be lower, but they generally swing back to a pretty comfortable state. Around the 1950s, though, the global average temperature began to climb to unprecedented levels. Our ancient temperature records never showed such a sudden increase. When we look at the time period from 1950 to today, we can see that while temperatures still swing back down some years, these colder years are still much hotter than the average temperatures in the past. Researchers noticed a change in the concentration of greenhouse gases in the Earth's atmosphere. These greenhouse gases trap heat from the sun in our atmosphere, similar to how a greenhouse allows sunlight to pass through its glass walls but prevents the heat it creates from leaving. This greenhouse effect is what keeps our planet warm and habitable enough for life. However, the amount of one particular greenhouse gas was rising, carbon dioxide or CO2. CO2 is naturally one of the most notable greenhouse gases besides water vapor, but we can also release CO2 by burning wood or fossil fuels like coal and oil. Over time, humans have increasingly relied on these fuels to power things like planes, cars, and trains as well as to generate electricity. As a result of these human activities, more CO2 is being released into the atmosphere than ever before, much more than is normally released by the Earth and at a much faster rate. The increasingly heavy blanket of greenhouse gases is trapping excess heat in our atmosphere rather than allowing more of it to radiate into space as normal. This is what's causing Earth's average temperature to rise beyond what scientists would expect based on historical patterns. While scientists once referred to this process as global warming, most now prefer the more general term, climate change. A world that's a little bit warmer on average might not seem like such a big deal, but we've learned that even a small shift in the planet's natural processes can have drastic consequences. When studying the early signs of climate change, scientists predicted that as cold places like North and South Pole got warmer, the ice would begin to melt. All of that frozen water suddenly flowing into the oceans would cause sea levels to rise, which would affect the planet's weather system. Have you heard all the news about weird weather in the past few years? Snow in places that's usually warm and dry, or drought in places that are usually cold and rainy, huge fires during extremely hot summers, severe storms battering coastlines and flooding cities. Many of these natural hazards used to be somewhat rare, but now they're becoming more common, exactly as climate scientists predicted. People have relied on relatively consistent weather patterns for generations, so they aren't prepared to adapt to these changes in their local environment. Communities that are already feeling the effects of climate change are worried that they're gonna lose their homes, their livelihoods, or their sources of food and water. Scientists are working on technologies that can help us remove some of the excess CO2 from the atmosphere, but in the meantime they recommend that we emit less CO2 in the first place. This would allow us to limit how much the global average temperature increases, giving communities time to adapt to changes in their surroundings. Of course, it's complicated to change the way our societies work. To help reduce CO2 emissions, you may see some people advocating for tweaking individual behaviors, like eating plant-based diets or using low carbon transportation methods. You may see others saying that since large organizations in highly populated countries emit the most CO2, we need to push them to make more wide raging institutional changes. As someone who works in environmental science, I know that sorting through all of these different facts and opinions on climate change can be overwhelming. It's difficult to think about living in a world that may be very different from what I've always known in the past. I've found it helpful to both adopt simple sustainable habits in my own life, while also seeking out community groups that work on bigger initiatives. It's easier to imagine the future when you help others to shape it. Now that we've taken some time to think about Earth's past and what's happening to it in the present, try looking towards the future of our planet. What is your ideal future? And how can you help to make it happen?