David Holmgren is an Australian environmental designer, ecological educator and writer. He is best known as one of the co-originators of the permaculture concept with Bill Mollison. David is passionate about the philosophical, conceptual and practical foundations for sustainability, and his book "=https://www.amazon.com/Permaculture-Principles-Pathways-beyond-Sustainability/dp/0646418440Principles and Pathways" is regarded as a major landmark in permaculture literature.
I've had the pleasure of meeting David and having a brief chat, at the launch of Retrosuburbia. He and Sue are terrific exemplars of self reliance through permaculture.
David is an engaging speaker, in person and online. Heaps of presence on YouTube, well worth a search.
Life is too short, plant a tree for those that follow.
When all four tires fall off your canoe, how many tiny ads does it take to build a doghouse?