A collection of repeat photography of glaciers from the National Snow and Ice Data Center (NSIDC). The photos are taken years apart at or near the same location, and at the same time of year. These images illustrate how dramatically glacier positions can change even over a relatively short period in geological time: 60 to 100 years. Background essay and discussion questions are included.

This PBS Learning Media activity addresses drought basics, including its causes and impacts and ways to assess it, by using media from NOAA and NASA. It defines the types of drought, the impacts, monitoring, and responses to drought. Use this resource to stimulate thinking and questions on the complexity of drought and to identify some variables used in defining drought.