The words of someone who no longer needs rely on mathematic modelling to understand how precious, limited Earth's atmosphere is.

“When I looked out the window of the International Space Station, I saw the paparazzi-like flashes of lightning storms, I saw dancing curtains of auroras that seemed so close it was as if we could reach out and touch them. And I saw the unbelievable thinness of our planet's atmosphere. In that moment, I was hit with the sobering realization that that paper-thin layer keeps every living thing on our planet alive. “I saw an iridescent biosphere teeming with life -I didn't see the economy. But since our human-made systems treat everything, including the very life-support systems of our planet, as the wholly owned subsidiary of the global economy, it's obvious from the vantage point of space that we're living a lie. We need to move from thinking economy, society, planet to planet, society, economy. That's when we're going to continue our evolutionary process.”; - retired astronaut Col. Ronald John Garan Jr., USAF