Courses on Khan Academy are always 100% free. Start practicing—and saving your progress—now!

Earth’s climate has changed over time due to natural events and processes. Volcanic eruptions, meteorite impacts, ocean currents, and greenhouse gases have all driven changes in climate—sometimes suddenly, sometimes slowly. Scientists use ice cores, tree rings, and other natural records to uncover how these forces shaped Earth’s past climate across centuries and millennia.

00:00 Intro
00:30 Climate vs weather
01:23 How volcanoes can disrupt climate
02:15 How a meteor can disrupt climate
03:44 Global ocean conveyer belt
04:29 Greenhouse gases
05:29 How do scientists study changes in climate
06:24 Summary

Khan Academy is a nonprofit organization with the mission of providing a free, world-class education for anyone, anywhere. We offer quizzes, questions, instructional videos, and articles on a range of academic subjects, including math, biology, chemistry, physics, history, economics, finance, grammar, preschool learning, and more. We provide teachers with tools and data so they can help their students develop the skills, habits, and mindsets for success in school and beyond. Khan Academy has been translated into dozens of languages, and 15 million people around the globe learn on Khan Academy every month. As a 501(c)(3) nonprofit organization, we would love your help!

Donate or volunteer today! Donate here: https://www.khanacademy.org/donate?utm_source=youtube&utm_medium=desc

Volunteer here: https://www.khanacademy.org/contribute?utm_source=youtube&utm_medium=desc

Credits:
“Alternate version of the greenhouse effect” by A loose necktie, licensed under a Creative Commons Attribution License (CC BY-SA 4.0): https://commons.wikimedia.org/wiki/File:Greenhouse-effect-t2.svg

“Mount Pinatubo eruption of 12 June 1991” by Dave Harlow, USGS, public domain: https://commons.wikimedia.org/wiki/File:Pinatubo91eruption_plume.jpg

“An ice core” by NASA's Goddard Space Flight Center/Ludovic Brucker, public domain: https://science.nasa.gov/science-research/earth-science/climate-science/core-questions-an-introduction-to-ice-cores/

“Ice core driller” by Jennifer Heldman, National Science Foundation (NSF), public domain: https://science.nasa.gov/science-research/earth-science/climate-science/core-questions-an-introduction-to-ice-cores/

“Thermohaline circulation” by Brisbane, licensed under a Creative Commons Attribution License (CC BY-SA 3.0): https://commons.wikimedia.org/wiki/File:Thermohaline_circulation.png