This video is part two of a seven-part National Academies series, Climate Change: Lines of Evidence. The video outlines, with the use of recent research and historical data, how we know that the Earth is warming.

This video explores what scientists know about how changes in global climate and increasing temperatures affect different extreme weather events.

This web-based activity tackles the broad reasons for undertaking ocean exploration - studying the interconnected issues of climate change, ocean health, energy and human health. Students examine the types of technology ocean scientists use to collect important data.

This series of visualizations show the annual Arctic sea ice minimum from 1979 to 2010. 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.

In this activity, students estimate the drop in sea level during glacial maxima, when ice and snow in high latitudes and altitudes resulted in lower sea levels. Students estimate the surface area of the world's oceans, use ice volume data to approximate how much sea levels dropped, and determine the sea-level rise that would occur if the remaining ice melted.

Developed for Alaska Native students, this activity can be customized for other regions. Students interview elders or other long-term residents of the community to document their knowledge of local changes to the landscape and climate. Based on the information and photos they acquired from the interview, students return to photo locations to observe and record changes. Finally, they develop ideas about potential impacts of a warming climate to the ecosystem that surrounds them.

This video on phenology of plants and bees discusses the MODIS satellite finding that springtime greening is happening one half-day earlier each year and correlates this to bee pollination field studies.

In this activity, students use maps and data to learn about where and how hurricanes form and possible correlations with climate change affecting their strength.

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 video examines the thawing of permafrost due to changes in climate and shows examples of the impacts that warming temperatures have on permafrost in the Arctic, including the release of the greenhouse gas methane. Dramatic results are shown, including sink holes forming on the landscape and beneath buildings, roads, and other infrastructure, causing some communities to relocate.