John Sibley III is one of the most respected leaders of Georgia's environmental movement. A tireless advocate for environmental concerns and far-sighted land use planning, Sibley has been a voice of conscience in rapidly-developing metro Atlanta for many years.

Sibley currently serves as executive director of the Captain Planet Foundation, which supports environmental education for kids in K-12. From 1998-2005, as president of the Georgia Conservancy, he led programs to promote environmental education, clean water, clean air, land conservation, and smart growth. He was director of former Governor Joe Frank Harris' Growth Strategies Commission in the 80s, where he worked closely with former GRTA chairman Joel Cowan. He also served as a member of the Governor's Development Council.

A graduate of Yale Law School, Sibley chaired the State Health Planning Review Board in which he supervised Georgia's administrative appeal process under the hospital "certificate of need" law. He worked as a consultant for Crisp and Dooly counties in 1994, organizing, supervising, and facilitating a comprehensive, community-based planning process for the counties. Although Sibley is an attorney, an advisor and a planner, he is best known as an environmentalist.