John Michael Greer is a author and blogger whose work focuses on the overlaps between ecology, spirituality, and the future of industrial society. He served twelve years as Grand Archdruid of the Ancient Order of Druids in America, and currently heads the Druidical Order of the Golden Dawn.
Ecosophia is his blog. If you're ever in need of some mind food. This is a good place to stop off. He was of course a guest on episodes 74 and 77 of the podcast and will be numerous times again!