This video segment, from the 'Earth: The Operators' Manual' featuring climate expert Richard Alley, shows how ice cores stored at the National Ice Core Lab provide evidence that ancient ice contains records of Earth's past climate - specifically carbon dioxide and temperature.

This National Geographic video explains the origins of the El NiÃo Southern Oscillation using animations and shows the impacts on humans, wildlife and habitat, particularly in the United States.

This animated visualization represents a time history of atmospheric carbon dioxide in parts per million (ppm) from 1979 to 2016, and then back in time to 800,000 years before the present.

In this activity, students examine climate variability in the North Atlantic associated with the North Atlantic Oscillation (NOA) in a case study format.

Climate has varied in the past, but today's climate change rate is much more drastic due to human activity. Students explore past climate cycle graphs and compare the cycles with the current rate of change.

This activity allows students to make El Nino in a container, but it might work better as a teacher demonstration. The introduction and information provided describe El Nino, its processes and its effects on weather elsewhere in the world.

This animated visualization of precession, eccentricity, and obliquity is simple and straightforward and provides text explanations. It is a good starting place to show Milankovitch cycles.

This NASA animation of the Five-Year Average Global Temperature Anomalies from 1881 to 2009 shows how temperature anomalies have varied in the last 130 years. The color-coded map displays a long-term progression of changing global surface temperatures from 1881 to 2009. Dark red indicates the greatest warming and dark blue indicates the greatest cooling.

This multi-part activity introduces users to normal seasonal sea surface temperature (SST) variation as well as extreme variation, as in the case of El NiÃo and La NiÃa events, in the equatorial Pacific Ocean. Via a THREDDS server, users learn how to download seasonal SST data for the years 1982 to 1998. Using a geographic information system (GIS), they visualize and analyze that data, looking for the tell-tale SST signature of El NiÃo and La NiÃa events that occurred during that time period. At the end, students analyze a season of their own choosing to determine if an El NiÃo or La NiÃa SST pattern emerged in that year's data.

This video illustrates how atmospheric particles, or aerosols (such as black carbon, sulfates, dust, fog), can affect the energy balance of Earth regionally, and the implications for surface temperature warming and cooling.