 Dr. Joyner taught previously at George Washington University, the University of Virginia, Dartmouth College and Muhlenberg College and had been a senior research fellow with the Woods Hole Oceanographic Institution and the Institute for Antarctic and Southern Ocean Studies at the University of Tasmania, Australia.At Georgetown, he taught courses on international law, international organization, and global environmental regimes.Recognized as one of the leading experts on international law and Antarctica, he was the author of numerous books, including "International Law in the 21st Century