Terry Spahr is the Executive Director of new feature length documentary 8 Billion Angels and founder of Earth Overshoot

From the 8 Billion Angels website:

Environmentalist and activist Terry Spahr left the corporate world to research, write and produce 8 Billion Angels, a documentary feature which exposes overpopulation as the upstream cause of all our environmental emergencies. Terry is the Founder and Executive Director of Earth Overshoot, a non-profit designed to promote public and private action to make ecological limits central to all decision-making. A graduate of the University of Pennsylvania College of Arts & Sciences and Fels Center of Government, Terry lectures on issues of sustainability to students, investor groups, and civic organizations. He is a regular opinion writer for a variety of environmental publications.

Terry Spahr has been a guest on 1 episode.