http://russgeorge.net/2016/06/17/plankton-will-stop-making-oxygen-by-end-of-century/

Among the deadly threats our generation is amplifying explosively, the simplest way to wipe out life on Earth is to destabilize the atmosphere. Today, it is possible to produce a weapon that can accomplish this practically overnight. But barring that purposeful threat, our species may accomplish the same result with nothing more than unbridled consumption of fossil fuels and totally ignoring the impact of billions of machines and cities on the global ecologies.

It is still possible for our species to transform rapidly into a form that doesn’t wipe out everything in sight, all day every day, for the sake of nonsensical entitlements and personal convenience. What the future depends upon is a small group of intelligent, committed people engineering another way of life that is too contagiously brilliant to stand aside from. It isn’t a matter of the probabilities. It’s a matter of life and death for the entire history and future of organisms on our world.