Complex sentence: Timothy Francis Ball, Ph.D., is a retired university professor who heads the Natural Resources Stewardship Project and is the former head of Friends of Science, a non-profit organization of those who are skeptical of human-caused global warming.
Split into simpler sentences: Timothy Francis Ball, Ph.D., is a retired university professor and global warming skeptic. He heads the Natural Resources Stewardship Project and is the former head of Friends of Science, a non-profit organization of those who are skeptical of human-caused global warming.