Exponential growth inside a finite system leads to collapse.

Richard Powers, The Overstory

In essence, the planet runs on a cycle of water-splitting by photosynthesis to form oxygen and the production of water by respiration.

Paul G. Falkowski in Life's Engines:  How Microbes Made Earth Habitable

If I calculate the average annual quota required to limit global warming to two degrees this century I find that simply maintaining a typical American single-family home exceeds it in two weeks. Absent any indication of direct harm, what makes intuitive moral sense is to live the life I was given, be a good citizen, be kind to the people near me, and conserve as well as I reasonably can.... [Climate change] deeply confuses the human brain, which evolved to focus on the present, not the far future, and on readily perceivable movements, not slow and probabilistic developments.

Jonathan Franzen, "Carbon Capture: Has climate change made it harder for people to care about conservation?" in the New Yorker of April 6, 2015