This is a sequence of 5 classroom activities focusing on the El NiÃo climate variability. The activities increase in complexity and student-directedness. The focus of the activities is on accessing and manipulating real data to help students understand El NiÃo as an interaction of Earth systems.

In this activity, students analyze data maps of sea surface temperature anomalies for a 14-year interval and create an ENSO time line in a case study format. Based on their findings, students determine the recurrence interval of the ENSO system.

In this activity, students are introduced to tree rings by examining a cross section of a tree, also known as a 'tree cookie.' They discover how tree age can be determined by studying the rings and how ring thickness can be used to deduce times of optimal growing conditions. Next, they investigate simulated tree rings applying the scientific method to explore how climatic conditions varied over time.

In this activity, students work with climate data from the tropical Pacific Ocean to understand how sea-surface temperature and atmospheric pressure affect precipitation in the tropical Pacific in a case study format.

This short video clip summarizes NOAA's annual State of the Climate Report for 2009. It presents a comprehensive summary of Earth's climate in 2009 and establishes the last decade as the warmest on record. Reduced extent of Arctic sea ice, glacier volume, and snow cover reflect the effects of rising global temperature.

This is an activity designed to allow students who have been exposed to the El NiÃo-Southern Oscillation to analyze the La NiÃa mechanism and predict its outcomes in a case study format.

This interactive displays how climate variables are changing over time (temperature, CO2, Arctic sea ice, sun's energy, sea level, etc.) in graphical form. Students can easily examine over 50+ years of archived data.

In this activity, students explore past examples of climate variability in three locations: the Peruvian and Bolivian Andes, Central America, and coastal Greenland, and consider differences between climate variability and climate change.

This is an interactive website that provides descriptive information and data related to ten key climate indicators. These climate indicators and related resources show global patterns and data that are intuitive and compelling teaching tools.

This classroom resource is a combination of 3 visualizations and accompanying text that illustrate how 3 key natural phenomena - cyclical changes in solar energy output, major volcanic eruptions over the last century, and El Nino/Nina cycles - are insufficient to explain recent global warming.