Born in Williamsport, Pennsylvania, he now lives in Berkeley, California. For many years he edited the Natural History Guides at the University of California Press. He is known as author of green books, namely as author of the ecological utopia Ecotopia (1975). He is said to have coined the word ecotopia.

Other books of Callenbach include:

• Ecotopia Emerging (1981)
• The Ecotopian Encyclopedia
• Ecology: A pocket guide (1998)
• Living Cheaply With Style: Live Better and Spend Less (1993?)
• Bring Back the Buffalo!: A Sustainable Future for America's Great Plains (2000)