This video highlights a team of scientists who work on reconstructing the mass extinction that occurred 250 million years ago, the end of the Permian Period. This event wiped out the majority of life on our planet, resetting the evolution of life. Clues suggest that deadly bacteria might have set off a chemical chain reaction that poisoned the Permian seas and atmosphere.

In this activity, students will practice the steps involved in a scientific investigation as they learn why ice formations on land (and not those on water) will cause a rise in sea level upon melting. This is a discovery lesson on ice and water density and displacement of water.

This is a collection of five short videos that show how climate change is affecting fishing, native populations and access for the oil and gas industry in the Arctic. The videos include personal reflections by writers Andrew C. Revkin and Simon Romero, scientists, and residents about their experience of the impacts of the climate change in the Arctic.

This animation shows the Arctic sea ice September (minimum) extents from 1979-2014.

In this video segment, a team of scientists seeks evidence to support their hypothesis that atmospheric warming may cause water to form beneath the West Antarctic ice sheet. This water causes ice streams to flow much more quickly than the rest of the ice sheet, which has important implications for sea level rise.

This video is part of the Climate Science in a Nutshell series. This short, animated video looks at evidence of a rapidly warming planet. It discusses how air bubbles in ice cores can be used to estimate Earth's average air temperature for thousands of years and how direct measurements document air temperatures from 1880.

This short video features the Alaska Lake Ice and Snow Observatory Network (ALISON project), a citizen science program in which 4th and 5th graders help scientists study the relationship between climate change and lake ice and snow conditions.

In this video, students learn that scientific evidence strongly suggests that different regions on Earth do not respond equally to increased temperatures. Ice-covered regions appear to be particularly sensitive to even small changes in global temperature. This video segment adapted from NASA's Goddard Space Flight Center details how global warming may already be responsible for a significant reduction in glacial ice, which may in turn have significant consequences for the planet.

This series of visualizations show the annual Arctic sea ice minimum from 1979 to 2015. The decrease in Arctic sea ice over time is shown in an animation and a graph plotted simultaneously, but can be parsed so that the change in sea ice area can be shown without the graph.

This activity in a case study format explores ice loss from the Greenland ice sheet by way of outlet glaciers that flow into the ocean. Students do basic calculations and learn about data trends, rates of change, uncertainty, and predictions.

Pages