https://www.khanacademy.org/science/strengthened-shs-earth-and-space-science-1/x006d5d274c051fd7:origin-and-structure-of-the-earth/x006d5d274c051fd7:earth-s-place-in-the-solar-system/v/bhp-earth-and-early-atmosphere 2023-07-02T10:05:56.724382666Z WATCH: Earth and the Early Atmosphere The Earth's atmosphere keeps changing, creating an endless cycle of warming, cooling, and recovery. Discover how Earth's early atmosphere formed and evolved, as violent collisions that created intense heat and pressure, the formation of oceans, and the creation of the moon. Explore the rise of oxygen, the role of cyanobacteria, and the changes that led to today's diverse life forms. Big History Project video https://cdn.kastatic.org/googleusercontent/Sfjp8NfDD5pJAsTFtTPhmuuPF9JkRzobuADDtJ33zckSRw4j85FMXBJqiPJJzn41bP70vyYXxlBCQtBUpYPUiwA WATCH: Earth and the Early Atmosphere The Earth's atmosphere keeps changing, creating an endless cycle of warming, cooling, and recovery. Discover how Earth's early atmosphere formed and evolved, as violent collisions that created intense heat and pressure, the formation of oceans, and the creation of the moon. Explore the rise of oxygen, the role of cyanobacteria, and the changes that led to today's diverse life forms. https://cdn.kastatic.org/ka-youtube-converted/Gyn754vw8ZQ.mp4/Gyn754vw8ZQ.mp4 333 Climate change https://www.khanacademy.org/science/strengthened-shs-biology-2/x62f5297cda63eb8d:plant-organ-systems/x62f5297cda63eb8d:importance-of-plants/v/bhp-atmosphere-climate 2023-10-12T14:09:03.712558587Z WATCH: The Atmosphere and Climate Earth's climate has always changed due to natural cycles. But human activities, especially since the Industrial Revolution, have increased carbon dioxide levels, intensifying the greenhouse effect. This human-induced global warming could raise temperatures more than typical natural fluctuations, threatening habitats and causing sea-level rise. To combat this, global commitment to energy conservation, sustainable energy, and forest preservation is needed. Big History Project video https://cdn.kastatic.org/googleusercontent/yRX2cJC5JYpwonfB5Xvt6R8s_nWRSpGYLjtVjQakRHiNZWod55B1fHdto2xZJgGxABtaP0l9lBZjGI2Gw9ESQrwZ WATCH: The Atmosphere and Climate Earth's climate has always changed due to natural cycles. But human activities, especially since the Industrial Revolution, have increased carbon dioxide levels, intensifying the greenhouse effect. This human-induced global warming could raise temperatures more than typical natural fluctuations, threatening habitats and causing sea-level rise. To combat this, global commitment to energy conservation, sustainable energy, and forest preservation is needed. https://cdn.kastatic.org/ka-youtube-converted/Jfaipkw691E.mp4/Jfaipkw691E.mp4 219 Climate change https://www.khanacademy.org/science/cambridge-o-level-chemistry-cie/x8bc8fb44369617ed:chemistry-of-the-environment/x8bc8fb44369617ed:air-quality-and-climate/a/before-you-watch-what-is-climate-change-crash-course-climate-energy-1 2024-08-14T01:23:16.657326838Z WATCH: What is Climate Change? This video introduces some core concepts that will help guide us throughout the course, like the difference between climate and weather. We’ll also take a look back through the Earth’s history at other periods of significant climate change. article https://www.khanacademy.org/science/10th-grade-science-matatag/xaf924d0c475e22d4:1st-quarter/xaf924d0c475e22d4:climate-change/a/read-data-exploration-how-do-we-know-climate-change-is-real 2024-09-26T20:55:17.177415621Z READ: Data Exploration - How Do We Know Climate Change Is Real? The global scientific community agrees that climate change is happening, and it’s caused by human activity. In this article, you’ll dig into four charts about global temperature anomaly, CO2 emissions, and the correlations between them. article https://www.khanacademy.org/science/middle-school-earth-and-space-science/x87d03b443efbea0a:earth-and-society/x87d03b443efbea0a:earths-changing-climate/v/earths-changing-climate 2025-07-01T18:08:15.179962416Z Earth's changing climate 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. Khan Academy video https://cdn.kastatic.org/ka_thumbnails_cache/b5d3f3c1-1fcf-4639-87b1-1da887ae0544_1280_720_base.png Earth's changing climate 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. https://cdn.kastatic.org/ka-youtube-converted/z9xKxciHgo8.mp4/z9xKxciHgo8.mp4 270 Climate change https://www.khanacademy.org/science/middle-school-earth-and-space-science/x87d03b443efbea0a:earth-and-society/x87d03b443efbea0a:earths-changing-climate/e/apply-earths-changing-climate 2026-06-12T04:20:46.952280615Z Apply: Earth's changing climate Apply your understanding of climate change in this set of free, standards-aligned practice questions. Lauren Rosebrugh exercise https://www.khanacademy.org/science/cambridge-o-level-biology-cie/x2a084a90105205d2:relationships-of-organisms-with-one-another-and-with-the-environment/x2a084a90105205d2:effects-of-humans-on-ecosystems/a/earths-changing-climate 2026-04-28T11:00:37.315336883Z Key points: Earth's changing climate Review your understanding of climate change in this free article aligned to NGSS standards. article https://www.khanacademy.org/science/ap-college-environmental-science/x0b0e430a38ebd23f:global-change/x0b0e430a38ebd23f:greenhouse-effect/v/greenhouse-effect-and-greenhouse-gases 2024-06-28T21:00:15.59562973Z Greenhouse effect and greenhouse gases The greenhouse effect, driven by gases like carbon dioxide, methane, and water vapor, is essential for maintaining Earth's habitable temperatures. However, excessive concentrations of these gases—particularly due to human activities—can lead to global warming and climate change. Sal Khan video https://cdn.kastatic.org/ka_thumbnails_cache/27e417aa-bb45-422d-bb99-7e0e28da1250_1280_720_base.png Greenhouse effect and greenhouse gases The greenhouse effect, driven by gases like carbon dioxide, methane, and water vapor, is essential for maintaining Earth's habitable temperatures. However, excessive concentrations of these gases—particularly due to human activities—can lead to global warming and climate change. https://cdn.kastatic.org/ka-youtube-converted/YpfxiDktSoI.mp4/YpfxiDktSoI.mp4 419 Climate change https://www.khanacademy.org/science/cambridge-o-level-physics-cie/x0e04e0cb682fb793:transfer-of-thermal-energy/x0e04e0cb682fb793:thermal-radiation/v/the-_greenhouse_effect 2024-06-16T20:56:57.951759647Z The greenhouse effect Earth receives a spectrum of electromagnetic radiation from the Sun which peaks in the visible range. Some of this light makes it to Earth's surface and is absorbed. The absorbed light is converted to thermal vibrations of charged particles, which then radiate infrared light. Greenhouse gases in the atmosphere (including carbon dioxide, methane, and water vapor) absorb the infrared light and then re-emit it in random directions. Some escapes to space, and some remains trapped in the atmosphere. The greenhouse effect keeps Earth warm enough to be habitable. However, human activities are increasing greenhouse gas concentrations and are thereby affecting Earth's climate system. Solutions to this problem include solar, wind, and nuclear energy, which do not emit greenhouse gases during operation. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/4b17ace8-7bca-436f-a549-ed079209c44f_1280_720_base.png The greenhouse effect Earth receives a spectrum of electromagnetic radiation from the Sun which peaks in the visible range. Some of this light makes it to Earth's surface and is absorbed. The absorbed light is converted to thermal vibrations of charged particles, which then radiate infrared light. Greenhouse gases in the atmosphere (including carbon dioxide, methane, and water vapor) absorb the infrared light and then re-emit it in random directions. Some escapes to space, and some remains trapped in the atmosphere. The greenhouse effect keeps Earth warm enough to be habitable. However, human activities are increasing greenhouse gas concentrations and are thereby affecting Earth's climate system. Solutions to this problem include solar, wind, and nuclear energy, which do not emit greenhouse gases during operation. https://cdn.kastatic.org/ka-youtube-converted/Yn7ICU3Q4mE.mp4/Yn7ICU3Q4mE.mp4 808 Climate change https://www.khanacademy.org/science/ap-college-environmental-science/x0b0e430a38ebd23f:global-change/x0b0e430a38ebd23f:greenhouse-effect/e/greenhouse-effect 2026-04-15T05:40:45.550331962Z Greenhouse effect Apply your understanding of greenhouse effect in this set of free practice questions aligned to AP standards. exercise https://www.khanacademy.org/science/10th-grade-science-matatag/xaf924d0c475e22d4:1st-quarter/xaf924d0c475e22d4:climate-change/a/read-data-exploration-greenhouse-gas-emissions-ap 2023-07-13T03:22:42.672854219Z READ: Data Exploration – Greenhouse Gas Emissions The average temperature of the planet is rising, and it’s rising because humans are emitting more greenhouse gases (GHGs) into the atmosphere. Since the Industrial Revolution, the global temperature has risen by about 1 degree Celsius. This might not seem like much, but climate scientists warn that an increase of 2 degrees Celsius from pre-industrial levels could be catastrophic. Every region of the world produces more greenhouse gases today than 100 years ago, but some regions produce far more than others. These trends could improve or get worse, but that depends on what actions humans take now and in the future. article https://www.khanacademy.org/science/10th-grade-science-matatag/xaf924d0c475e22d4:1st-quarter/xaf924d0c475e22d4:climate-change/a/before-you-watch-understanding-the-impacts-of-climate-change 2024-08-16T21:36:57.70129951Z WATCH: Understanding the Impacts of Climate Change How do we know that climate change is impacting our planet? This video explores some of the worst direct impacts of climate change and some dangerous tipping points humanity must avoid. article https://www.khanacademy.org/humanities/climate-project/x7467a46e12a31203:the-impacts-of-climate-change/x7467a46e12a31203:indirect-impacts-of-climate-change-2-3/e/exercise-3 2024-08-22T20:07:12.047866438Z PRACTICE: The Impacts of Climate Change This exercise is all about understanding how climate change affects us and the world around us, from natural ecosystems to human communities. Let's dive into the impacts of climate change and see how well you can identify and explain these changes! Eman E exercise https://www.khanacademy.org/science/grade-12-chemistry-snc-aligned/x7a43e770fc9e15cf:industry/x7a43e770fc9e15cf:applied-and-industrial-chemistry-for-sustainable-development/a/read-the-impacts-of-climate-change 2024-09-26T20:55:17.177415621Z READ: The Impacts of Climate Change Climate change is already impacting us all, but not everyone experiences it in the same way. Learn about the difference between direct and indirect impacts of climate change, and how these effects are interconnected. article https://www.khanacademy.org/science/10th-grade-science-matatag/xaf924d0c475e22d4:1st-quarter/xaf924d0c475e22d4:climate-change/a/read-data-exploration-the-direct-impacts-of-climate-change 2024-09-26T20:55:17.177415621Z READ: Data Exploration - The Direct Impacts of Climate Change This data exploration focuses on global sea-level rise—its connections to greenhouse gas emissions and the ways it threatens human communities all over the world. article https://www.khanacademy.org/science/10th-grade-science-matatag/xaf924d0c475e22d4:1st-quarter/xaf924d0c475e22d4:climate-change/a/activity-direct-impacts-of-climate-change 2024-09-26T20:55:17.177415621Z ACTIVITY: Direct Impacts of Climate Change Choose three direct impacts of climate change, assess the evidence for these impacts, and make predictions about how these direct impacts will affect human and natural systems. article https://www.khanacademy.org/science/ap-college-environmental-science/x0b0e430a38ebd23f:global-change/x0b0e430a38ebd23f:climate-change/v/climate-emergency-feedback-loops-albedo 2025-08-08T21:39:42.49220884Z Climate emergency: feedback loops - albedo Climate change is setting off dangerous feedback loops at the Poles. The melting of Arctic ice and snow decreases Earth' ability to reflect the Sun's rays, leading to further heating and melting of ice and snow. In Antarctica, the warmer climate is melting ice sheets, leading to raised sea levels, which melts ice sheets further in an amplifying loop. Khan Academy video https://cdn.kastatic.org/ka_thumbnails_cache/6ec1ba8b-47e9-41c4-a470-0ad8a164d756_1280_720_base.png Climate emergency: feedback loops - albedo Climate change is setting off dangerous feedback loops at the Poles. The melting of Arctic ice and snow decreases Earth' ability to reflect the Sun's rays, leading to further heating and melting of ice and snow. In Antarctica, the warmer climate is melting ice sheets, leading to raised sea levels, which melts ice sheets further in an amplifying loop. https://cdn.kastatic.org/ka-youtube-converted/HNqTxBHgC0Y.mp4/HNqTxBHgC0Y.mp4 636 Climate change https://www.khanacademy.org/science/ap-college-environmental-science/x0b0e430a38ebd23f:global-change/x0b0e430a38ebd23f:climate-change/v/climate-emergency-feedback-loops-permafrost 2023-05-01T21:01:15.296908287Z Climate emergency: feedback loops - permafrost Global warming is causing the thawing of permafrost, the icy expanse of frozen ground covering one-quarter of the Northern Hemisphere. As it melts, previously frozen carbon stored in plant and animal remains is released into the atmosphere as heat-trapping greenhouse gases, warming the climate further, and melting more permafrost in a dangerous feedback loop. Khan Academy video https://cdn.kastatic.org/ka_thumbnails_cache/332b4108-1d94-487f-a064-fd2d1341e6ed_1280_720_base.png Climate emergency: feedback loops - permafrost Global warming is causing the thawing of permafrost, the icy expanse of frozen ground covering one-quarter of the Northern Hemisphere. As it melts, previously frozen carbon stored in plant and animal remains is released into the atmosphere as heat-trapping greenhouse gases, warming the climate further, and melting more permafrost in a dangerous feedback loop. https://cdn.kastatic.org/ka-youtube-converted/e44IYZ-gQnE.mp4/e44IYZ-gQnE.mp4 655 Climate change https://www.khanacademy.org/science/biology/biodiversity-and-conservation/threats-to-biodiversity/v/ocean-acidification-and-biodiversity-impacts 2021-03-18T10:33:23Z Demystifying ocean acidification and biodiversity impacts Why rising carbon dioxide levels in the atmosphere affect the acidity of the ocean, and what the consequences are for marine life. Video by California Academy of Sciences. California Academy of Sciences video https://cdn.kastatic.org/googleusercontent/6YMU-CjQIlS4BSH5nuCYtNKXHOR56CiaBGW3M27MYwMNoI5KUIcZ6Z-jCcEWiFJCvaTHutY6sRF3BURNZGGGej4 Demystifying ocean acidification and biodiversity impacts Why rising carbon dioxide levels in the atmosphere affect the acidity of the ocean, and what the consequences are for marine life. Video by California Academy of Sciences. https://cdn.kastatic.org/ka-youtube-converted/GL7qJYKzcsk.mp4/GL7qJYKzcsk.mp4 733 Climate change https://www.khanacademy.org/science/cambridge-o-level-chemistry-cie/x8bc8fb44369617ed:chemistry-of-the-environment/x8bc8fb44369617ed:air-quality-and-climate/e/greenhouse-effect-and-acid-rain 2025-02-13T13:42:33.753834602Z Greenhouse effect and Acid rain Let's solve some questions! vibhor exercise https://www.khanacademy.org/science/ap-college-environmental-science/x0b0e430a38ebd23f:global-change/x0b0e430a38ebd23f:climate-change/v/ocean-acidification 2024-06-28T21:00:15.59562973Z Ocean acidification Ocean acidification, a result of increased atmospheric carbon dioxide, is making our oceans more acidic, disrupting the formation of calcium carbonate in sea life and disturbing their homeostasis. This phenomenon is linked to emissions from human activities, such as the combustion of fossil fuels, driving vehicles, and deforestation. Sal Khan video https://cdn.kastatic.org/ka_thumbnails_cache/f325610b-22f7-4284-876a-a8bb55d7c250_1280_720_base.png Ocean acidification Ocean acidification, a result of increased atmospheric carbon dioxide, is making our oceans more acidic, disrupting the formation of calcium carbonate in sea life and disturbing their homeostasis. This phenomenon is linked to emissions from human activities, such as the combustion of fossil fuels, driving vehicles, and deforestation. https://cdn.kastatic.org/ka-youtube-converted/8JUEga3MYsM.mp4/8JUEga3MYsM.mp4 325 Climate change https://www.khanacademy.org/science/ap-college-environmental-science/x0b0e430a38ebd23f:energy-resources-and-consumption/x0b0e430a38ebd23f:intro-to-energy-resources-and-consumption/v/renewable-and-nonrenewable-energy-resources 2025-08-08T21:39:42.49220884Z Renewable and nonrenewable energy resources Energy sources are categorized into renewable and nonrenewable types. Nonrenewable energy sources are those that exist in a fixed amount and involve energy transformation that cannot be easily replaced. Renewable energy sources are those that can be replenished naturally, at or near the rate of consumption, and reused. Khan Academy video https://cdn.kastatic.org/ka_thumbnails_cache/4a933d4d-ab94-44f6-bbad-d41266274892_1280_720_base.png Renewable and nonrenewable energy resources Energy sources are categorized into renewable and nonrenewable types. Nonrenewable energy sources are those that exist in a fixed amount and involve energy transformation that cannot be easily replaced. Renewable energy sources are those that can be replenished naturally, at or near the rate of consumption, and reused. https://cdn.kastatic.org/ka-youtube-converted/G2lQFo69_hc.mp4/G2lQFo69_hc.mp4 181 Climate change https://www.khanacademy.org/science/mh-grade-7-science-bridge-course/x56692d2e23af6709:work-and-energy/x56692d2e23af6709:science-technology-and-environment/e/alternative-sources-of-energy 2026-06-15T02:00:46.78238584Z Renewable and non-renewable sources of energy Let's solve some problems to better understand alternative sources of energy. Aakash Bagga exercise https://www.khanacademy.org/science/ap-college-environmental-science/x0b0e430a38ebd23f:energy-resources-and-consumption/x0b0e430a38ebd23f:intro-to-energy-resources-and-consumption/a/renewable-and-nonrenewable-energy-sources 2026-06-16T10:19:15.850403834Z Key points: Renewable and nonrenewable energy sources Review your understanding of renewable and nonrenewable energy sources in this free article aligned to AP standards. article https://www.khanacademy.org/science/revision-up-science-class-6-full-term/x00110b31861f2508:week-4/x00110b31861f2508:nature-s-treasures/e/sources-of-energy-renewable-and-non-renewable 2026-04-15T04:20:43.780498197Z Sources of Energy (Renewable and non-renewable) LO: Sources of energy (fuel, food, biogas, wind, hydro, solar etc). Revathi exercise https://www.khanacademy.org/science/10th-grade-science-matatag/xaf924d0c475e22d4:1st-quarter/xaf924d0c475e22d4:climate-change/a/before-you-watch-how-will-climate-change-continue-to-affect-us-crash-course-climate-energy-8 2024-08-15T15:26:21.538433905Z WATCH: How Will Climate Change Continue to Affect Us? Climate change is already being felt by ecosystems and communities around the world, but not always in the same ways or to the same extent. This video explores the current and potential effects of climate change. article https://www.khanacademy.org/science/10th-grade-science-matatag/xaf924d0c475e22d4:1st-quarter/xaf924d0c475e22d4:climate-change/a/before-you-watch-adapting-to-a-changing-climate 2024-08-16T21:36:57.70129951Z WATCH: Adapting to a Changing Climate Adapting to climate change will require innovation across many different fields of research. This video produced by Wondrium introduces new innovations, such as drought-resistant maize and coastal carbon capture, that will help us adapt to a changing planet. article https://www.khanacademy.org/humanities/climate-project/x7467a46e12a31203:adaptation-and-innovation/x7467a46e12a31203:climate-change-adaptation-3-2/e/exercise-4 2024-08-22T20:07:12.047866438Z PRACTICE: Climate Change Solutions In this exercise, you'll check your understanding of the different ways we can tackle climate change. You'll also evaluate which adaptation strategies can best help us cope with a warming planet. Let's see how well you understand these important climate actions! Eman E exercise https://www.khanacademy.org/science/10th-grade-science-matatag/xaf924d0c475e22d4:1st-quarter/xaf924d0c475e22d4:climate-change/a/read-adaptation-solutions 2024-09-26T20:55:17.177415621Z READ: Adaptation Solutions Adaptation solutions comes in all shapes and sizes, but it is helpful to be able to categorize and compare them. This article helps you evaluate these solutions to decide where time, energy, and money should be invested. article https://www.khanacademy.org/science/10th-grade-science-matatag/xaf924d0c475e22d4:1st-quarter/xaf924d0c475e22d4:climate-change/a/read-resilient-cities 2024-09-26T20:55:17.177415621Z READ: Resilient Cities We need to adapt our cities to be more resilient in the face of climate change, and one place to start is with our buildings. This infographic explores building adaptations that can make our cities more resilient and livable. article https://www.khanacademy.org/science/10th-grade-science-matatag/xaf924d0c475e22d4:1st-quarter/xaf924d0c475e22d4:climate-change/a/activity-adaptation-solution-research 2024-09-26T20:55:17.177415621Z ACTIVITY: Adaptation Solution Research Research and evaluate a climate change adaptation solution of your choice. By digging into a single strategy, you’ll be better equipped to assess and understand the value of adaptation solutions you encounter in the future. article https://www.khanacademy.org/science/hs-bio/x230b3ff252126bb6:biodiversity-and-human-impacts/x230b3ff252126bb6:sustainability/a/human-activities-and-sustainability 2026-04-29T11:20:48.686238051Z Learn: Human activities and sustainability Learn how sustainability reduces the impact of human activities and conserves natural resources for future generations to use. article https://www.khanacademy.org/science/cambridge-o-level-biology-cie/x2a084a90105205d2:relationships-of-organisms-with-one-another-and-with-the-environment/x2a084a90105205d2:conservation/e/human-activities-and-sustainabiltiy 2026-06-15T04:30:38.969568377Z Human activities and sustainabiltiy Let's practice! vibhor exercise https://www.khanacademy.org/science/ap-college-environmental-science/x0b0e430a38ebd23f:land-and-water-use/x0b0e430a38ebd23f:intro-to-sustainable-practices/e/intro-to-sustainable-practices 2026-04-15T07:10:35.354439598Z Intro to sustainable practices Apply your understanding of intro to sustainable practices in this set of free practice questions aligned to AP standards. exercise