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.
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 calculate temperatures during a time in the geologic record when rapid warming occurred using a well known method called 'leaf-margin analysis.' Students determine the percentage of the species that have leaves with smooth edges, as opposed to toothed, or jagged, edges. Facsimiles of fossil leaves from two collection sites are examined, categorized, and the data is plugged into an equation to provide an estimate of paleotemperature for two sites in the Bighorn Basin. It also introduces students to a Smithsonian scientist who worked on the excavation sites and did the analysis.
This visualization graphically displays temperature and CO2 concentration in the atmosphere as derived from ice core data from 400,000 years ago to 1950. The data originates from UNEP GRID Arendal's graphic library of CO2 levels from Vostok ice core.
In this hands-on activity, students will learn about dendrochronology (the study of tree rings to understand ecological conditions in the recent past) and come up with conclusions as to what possible climatic conditions might affect tree growth in their region. Students determine the average age of the trees in their schoolyard, investigate any years of poor growth, and draw conclusions about the reasons for those years.
This video is the second of a three-video series in the Sea Change project, which follows the work of Dr. Maureen Raymo, paleogeologist at Columbia University's Lamont-Doherty Earth Observatory, who travels with fellow researchers to Australia in search of evidence of sea level that was once higher than it is today.
In this activity, students examine pictures of pollen grains representing several species that show the structural differences that scientists use for identification. Students analyze model soil samples with material mixed in to represent pollen grains. They then determine the type and amount of 'pollen' in the samples and, using information provided to them, determine the type of vegetation and age of their samples. Finally, they make some conclusions about the likely climate at the time the pollen was shed.