Activity on Egypt's Old Kingdom and how societies meet the environmental challenges faced. Students review the article on the Old Kingdom and in small groups, develop a strategy to deal with the Nile River. Questions for writing and...

Martin Hoffert, professor of physics at New York University, discusses global warming and alternative energies in this interview from the NOVA/FRONTLINE: "What's Up with the Weather?"

Government-sponsored site provides information about saving money and conserving energy by using energy-efficient products and practices at home and at business and organizational sites. Some resources in Spanish.

The number of cheetahs in the African wilderness has dwindled dramatically in the last 20 years. Find out what is being done in the United States to ensure the survival of this species.