Paul Hawken, the renowned environmental entrepreneur and author of 'Blessed Unrest,' told graduates there is invisible writing on the back of their diplomas that they'd need lemon juice to decode. His message was one of urgent optimism: the earth needs a new operating system, they are the programmers, and it's needed within a few decades. Every living system on the planet is declining, and the rate of decline is accelerating — but rather than despairing, Hawken framed this as the greatest job posting in history. The speech went viral and has been viewed millions of times, becoming one of the most shared commencement addresses of its era.