Human activities increasingly dominate 9 crucial planetary systems. Add to the familiar ones---climate, biodiversity, and chemical pollution---atmospheric aerosols, ocean acidification, excess nitrogen in agriculture, too much land in agriculture, freshwater scarcity, and ozone depletion. To have "a safe operating space for humanity" on Earth requires adjusting our behavior to work within those systems. How we collectively step up to that responsibility will determine whether "the Anthropocene" (the current geological era shaped by humans) will be a tragedy or humanity's greatest accomplishment. British environmentalist Mark Lynas is the author of one of the finest climate books, Six Degrees, and of a new work, The God Species: How the Planet Can Survive the Age of Humans, which spells out a cohesive Green program for this century guided by the 9 boundaries.

Agricultural biodiversity is as much in need of defending as the world's wildlife. Countless varieties of plants and animals were bred by the world's peoples for talents specific to every soil, climate, and human culture. Most of them have been lost---their hard-won genetic sophistication extinguished. But many have survived, thanks to professional and amateur devotion, and they are wondrous---living embodiments of humanity's deepest traditions. Photojournalist Jim Richardson has been covering the agricultural beat for National Geographic since 1984. His spectacular photographs, and the stories he tells with them, are renowned.

A dazzlingly incisive presenter, Lawrence Lessig specializes in identifying deep systemic problems in public process (such as copyright malfunction and Congressional dysfunction) and then showing how they can be cured. Currently he is bearing down on the corruption of Congress by the practice of private funding for public elections through campaign contributions. He writes: "The dependency of modern campaign finance is the single most important cause of the bankruptcy of Congress. Fixing this bankruptcy is the single most important reform effort that Americans face just now." As he did with helping fix copyright problems via Creative Commons, he has a plan for reforming elections to reestablish Congressional trust and effectiveness. (Public trust in Congress is currently at 12%.) Lessig is director of the Edmond J. Safra Foundation Center for Ethics at Harvard University and author of Republic, Lost (2011) and Code and Other Laws of Cyberspace (2000 and 2006).

Rick Prelinger, a guerrilla archivist who collects the uncollected and makes it accessible, presents the 6th of his annual Lost Landscapes of San Francisco screenings. You'll see an eclectic montage of rediscovered and rarely-seen film clips showing life, landscapes, labor and leisure in a vanished San Francisco as captured by amateurs, newsreel cameramen and studio filmmakers.

As founder and librarian of the storied Internet Archive (deemed impossible by all when he started it in 1996), Brewster Kahle has practical experience behind his universalist vision of access to every bit of knowledge ever created, for all time, ever improving. He will speak to questions such as these: Can we make a distributed web of books that supports vending and lending? How can our machines learn by reading these materials? Can we reconfigure the information to make interactive question answering machines? Can we learn from past human translations of documents to seed an automatic version? And, can we learn how to do optical character recognition by having billions of correct examples? What compensation systems will best serve creators and networked users? How do we preserve petabytes of changing data?

Ecologically, the past is always present if you know where and how to look. Paleontologist-biologist-artist Laura Cunningham spent 20 years exploring California's archives and relic lands to reconstruct exactly what life used to look like here over the past 10,000 years. Her beautiful images and her insights about long-period ecological change are collected in her new book, A STATE OF CHANGE: Forgotten Landscapes of California. Like many regions, California is busy restoring portions of the natural environment to previous conditions---native meadows, riparian woodlands, salt marshes, old-growth forests, along with the animals that used to populate them. But there is no static past to restore TO. With Cunningham's guidance we can choose to restore to a particular period: say, before the white invasion; or, during the Medieval Warm Period; or, before the human invasion; or, during the Ice Ages. With her inspiration, we can begin to envisage the ecological changes coming over the next 10,000 years.

As the times accelerate and we face ever more kaleidoscopic careers, a crucial meta-skill is the ability to learn new skills extremely rapidly, extremely well. That practice has no better exemplar and proponent than Timothy Ferriss, author of The 4-Hour Body: An Uncommon Guide to Rapid-Fat Loss, Incredible Sex, and Becoming Superhuman. Not surprisingly, he has made himself adept at compelling presentations, this one prepared especially for the Long Now audience.

As organisms, cities, and companies scale up, they all gain in efficiency, but then they vary. The bigger an organism, the slower. Yet the bigger a city is, the faster it runs. And cities are structurally immortal, while corporations are structurally doomed. Scaling up always creates new problems; cities can innovate faster than the problems indefinitely, while corporations cannot. These revolutionary findings come from Geoffrey West's examination of vast quantities of data on the metabolic/economic behavior of organisms and organizations. A theoretical physicist, West was president of Santa Fe Institute from 2005 to 2009 and founded the high energy physics group at Los Alamos National Laboratory.

As chief scientist of one of the most highly respected conservation organizations, The Nature Conservancy, Peter Kareiva is surprisingly radical. "Look," he says, "we're in nature. The deal is how to work with it and how to help it work for us. The better we are at ensuring that people get nature's benefits, the better we'll be at doing conservation." Through his insistence on "evidence-based conservation," he finds most ecosystems far less fragile than people think and none that can be protected as pristine, because pristine doesn't exist any more. His focus is on working the human/nature interface for maximum benefit to both. Kareiva is co-founder of the Natural Capital Project---allying with Stanford University and the World Wildlife Fund to measure the economic value of ecosystems---and co-author of the textbook, Conservation Science: Balancing the Needs of People and Nature.

The frontier of biology these days is the genetics and ecology of bacteria, and the frontier of THAT is what's being learned about viruses. "The science of virology is still in its early, wild days," writes Carl Zimmer. "Scientists are discovering viruses faster than they can make sense of them." The Earth's atmosphere is determined in large part by ocean bacteria; every day viruses kill half of them. Every year in the oceans, viruses transfer a trillion trillion genes between host organisms. They evolve faster than anything else, and they are a major engine of the evolution of the rest of life. Our own bodies are made up of 10 trillion human cells, 100 trillion bacteria, and 4 trillion very busy viruses. Some of them kill us. Many of them help us. Some of them are us. Viral time is ancient and blindingly fast. Science journalist Carl Zimmer is the author of A Planet of Viruses; the best introduction to the subject. His previous books include Parasite Rex and Microcosm.