Video length: 9:04 min. This video is narrated by climate scientist Richard Alley.
It examines studies US Air Force conducted over 50 years ago on the warming effects of CO2 in the atmosphere and how that could impact missile warfare. The video then focuses on the Franz Josef glacier in New Zealand; the glacier is used to demonstrate glaciers formation, depth of snow fall in the past, and understand atmospheric gases and composition during the last Ice Age. Supplemental resources are available through the website.
Goals adapted from CLEAN Reviewers comments:
- Link past climates and the carbon cycle
- Demonstrate, through the history of the Franz Josef Glacier in New Zealand, that cyclic orbital variations or other "natural variability" alone cannot account for warming in recent decades
ACTIVITY DESCRIPTION AND TEACHING MATERIALS
Explore >> CO2 and the Atmosphere
TEACHING NOTES / CONTEXT FOR USE
Teaching Notes / Context For Use by CLEAN Reviewers:
- This video helps link past climates and the carbon cycle.
- Teacher may wish to make a study guide/question sheet for the video to keep students engaged in the video throughout the nine minutes.
About the Science
- Linking military research on the heat-trapping qualities of carbon dioxide from over 50 years ago demonstrates the multiple lines of evidence for the role of CO2 in Earth's climate system.
- Animations are used to describe Milankovich cycles and the ice ages. Finally, the video shows how glaciers act as bulldozers to create moraines that indicate past termini and animations of glacier retreat that result in icebergs, lake formation, etc.
- The video demonstrates, through the history of the Franz Josef Glacier in New Zealand, that cyclic orbital variations or other "natural variability" alone cannot account for warming in recent decades.
- The video shows how glaciers can be used to study past climate, allowing scientists to study past atmospheric composition, precipitation amounts, and temperatures.
- Comment from Expert Scientist: This is a nice video which shows how scientists are using glaciers and ancient air trapped in those glaciers to understand the Earth's climate history. The narration is easy to follow and is well supported by the images.
About the Pedagogy
- An annotated script is available at: http://earththeoperatorsmanual.com/annotated_script/lightbox2.html
Technical Details/Ease of Use
- Excellent time-lapse photography segments on retreating glaciers.
- Closed captioned text provided.
Assessment is at the discretion of the instructor.
REFERENCES AND RESOURCES
An annotated script is available at: http://earththeoperatorsmanual.com/annotated_script/lightbox2.html
Description by the activity author: How the warming effects of carbon dioxide were studied by the US Air Force immediately after World War 2, and why the varying orbit of Earth around the Sun drove the cycle of the Ice Ages. Alley demonstrates, through the history of the Franz Josef Glacier in New Zealand, that orbital variations (aka “natural variation”) alone did not make things cooler or warmer: that took the feedback effect of falling and rising levels of CO2.