Big History Project
WATCH: The Atmosphere and Climate
Explore climate change on a geologic time scale, and consider recent human impacts on climate and the atmosphere. Created by Big History Project.
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- How come more of the videos on the Khan academy don't have a similar instructional style? With simple visuals accompanying lecture about the topic? Is this only good for certain kinds of learners? Thanks, T.S.(6 votes)
- Instructional style is because it was what was used when khan started on
You Tube and is what is shown statistically, Students might be learning
here based on how khan teachers and they have just kept with the style.
They have Implemented the visual.(2 votes)
- This wouldn't happen if if weren't for humans but since we can't go back is there a way to reverse it I mean like make the ice build up and water levels going down ,and the temperature going back to normal is there a way to do it plus is there a way to solve our problem ,is there a way to still use our resources but use less of it?(3 votes)
- Yes, but the sad part is, even if freezing the water back works, its only temporary, and will cost more money and maybe even release more CO2 to power the machine, and it will have to be done numerous time. There are many ways to solve the problem though. Most of the world's countries are actually moving toward renewable energy at a very fast rate, and there are even countries who are 100% renewable like Iceland. Another way would be, taking the carbon emissions and sending them down the earth to react with rocks, to make carbonates, the government can even take CO2 from the air and use it for energy, but going Vegan is the best way to slow climate change down, as Meat Production releases tremendous amounts of methane, there are so many ways to solve global warming, but the stupid politicians are what is stopping us from doing so. The corrupt politicians just want money.(7 votes)
- what are the layers of the atmosphere(3 votes)
- How did it , impact the environment(2 votes)
- Things people should know not a loot=D(2 votes)
- Are there any videos describing how climate change occurs? What are the factors behind it? How do we know that it's just us who plays a big impact on Global Warming? I'm wondering; how do these natural disasters form? Also, I've always questioned about acid rain.(1 vote)
- On Khan Academy, there's a short playlist in the Environmental Science section that covers climate change, ozone depletion, and some other things. https://www.khanacademy.org/science/ap-college-environmental-science/x0b0e430a38ebd23f:global-change
The reason I've heard for why climate change may cause more natural disasters to form is that once the global temperature increases, it's easier for water to evaporate into the atmosphere, and this makes it easier for large storm systems and hurricanes to form. Acid rain comes from random chemicals in the atmosphere (most often caused by air pollutants) mixing with water and lowering the pH of rain. This can be dangerous for ecosystems that need a specific pH to function well, such as rivers for example.(2 votes)
- Wait, what grade is this for?!(1 vote)
- Do changes in temperature affect CO2 levels (?) and, if so, how is this dealt with in a time series model that measures the effect of CO2 on temperature?(1 vote)
- Do you any more ways to save the planet , bobby ? That can be done at home ?(1 vote)
- how do scientists measure rain water?(0 votes)
NARRATOR: The Earth has always experienced climate change. Variations in the planet's tilt and its orbit around the sun produce climate patterns called Milankovitch cycles. In the last few million years, the cycle has alternated between cold periods called Ice Ages and warmer periods called Interglacials. Scientists use a number of techniques to study climate. Pollen grains preserved in lake and bog sediments tell us about flora that thrived in the past. The rings of trees, thicker in warm wet years and thinner during cold dry ones, record the climate. Ice core samples, containing bubbles of ancient air, store data that goes back about one million years. And the chemistry of ocean sediments can provide an estimate of water temperatures going back 65 million years to the time of the dinosaurs. At the peak of the last Ice Age, about 21,000 years ago, an ice sheet covered most of Europe and North America. Our current geologic epoch, the Holocene, is an interglacial period that began 12,000 years ago. When the ice melted, numerous species of plants and animals prospered in the warmer climate. The stable temperatures of the Holocene enabled humans to develop agriculture. Eventually, humans began to impact the environment by clearing timber and depleting soil resources. Still, the atmosphere largely stayed the same throughout the agrarian era. Subtle natural climate changes had been normal but even changes of only a few degrees in average regional temperature can affect the biosphere, opening and closing waterways and influencing migrations. Human impact on the global climate increased sharply after the Industrial Revolution. Average temperatures began to rise in the early 20th century. This was largely caused by carbon dioxide emissions from the burning of fossil fuels such as coal, oil and natural gas. Carbon dioxide is a greenhouse gas. It absorbs invisible heat radiation from the Earth, emitting much of it back down. Consequently, the Earth's surface is heated by both visible sunlight and infrared radiation from the atmosphere in what is called the greenhouse effect. Scientists project that average global temperatures will increase by several degrees this century if nothing is done, perhaps even exceeding the five-degree temperature fluctuations typical between an ice age and an interglacial period. This will cause changes in weather patterns and sea levels will rise as the ice sheets on Greenland and Antarctica melt. Global warming threatens forest and ocean habitats, especially coral reefs, which live in a narrow range of temperature. To fight global warming, we'll need a global commitment to conserve energy, develop sustainable energy sources and preserve our forests.