In this activity, students work in groups, plotting carbon dioxide concentrations over time on overheads and estimating the rate of change over five years. Stacked together, the overheads for the whole class show an increase on carbon dioxide over five years and annual variation driven by photosynthesis. This exercise enables students to practice basic quantitative skills and understand how important sampling intervals can be when studying changes over time. A goal is to see how small sample size may give incomplete picture of data.

These graphs show carbon dioxide measurements at the Mauna Loa Observatory, Hawaii. The graphs display recent measurements as well as historical long term measurements. The related website summarizes in graphs the recent monthly CO2, the full CO2 Record, the annual Mean CO2 Growth Rate, and gives links to detailed CO2 data for this location, which is one of the most important CO2 tracking sites in the world.

This video describes the role that dendrochronology plays in understanding climate change, especially changes to high elevation environments at an upper tree line. Dendrochronologists from the Big Sky Institute sample living and dead trees, describe how correlations between trees are made, and explain how tree cores record climate changes.

This short video, adapted from NOVA, explains how Earth's position relative to the Sun might be responsible for the dramatic shift in the climate of what is now the Saharan nation of Djibouti.

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 video segment describes climate data collection from Greenland ice cores that indicate Earth's climate can change abruptly over a single decade rather than over thousands of years. The narrator describes how Earth has undergone dramatic climate shifts in relatively short spans of time prior to 8000 years ago. The video and accompanying essay provide explanations of the differences between weather and climate and how the climate itself had been unstable in the past, with wide variations in temperature occurring over decadal timescales.

This video describes why tropical ice cores are important and provide different information than polar ice cores, why getting them now is important (they are disappearing), and how scientists get them. The work of glaciologist Lonnie Thompson is featured, with a focus on his work collecting cores of ice from high mountain glaciers that contain significant data about past climate change.

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.

This video features research conducted at University of Colorado's Institute of Arctic and Alpine Research, which studies isotopes of hydrogen trapped in ice cores to understand climate changes in the past.

In this activity students work with data to analyze local and global temperature anomaly data to look for warming trends. The activity focuses on the Great Lakes area.

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