…A small window in which to act

The excruciating power of Zweig’s memoir lies in the pain of looking back and seeing that there was a small window in which it was possible to act, and then discovering how suddenly and irrevocably that window can be slammed shut.
When it’s too late to stop Racism, According to Stefan Zweig, The New Yorker, June 22, 2018
Smart people are beginning to understand the size of the problem, but they haven’t yet figured out the timing; they haven’t yet figured out that the latest science shows that this wave is already breaking over our heads.
— Bill McKibben, 2010, on climate change. Eaarth, p 51
The true debate lies in the solutions and in mobilizing the social and political will to act upon our knowledge. Deciding not to act is a choice itself, and one that we cannot correct later. The time to act is always now. Because the longer we wait, the worse the outcomes will be.
— Climate scientist Andrea Dutton, in Axios, Special report: A 30-year alarm on the reality of climate change

Conversely

Things take the time they take. Don’t—
worry.
How many roads did St. Augustine follow
before he became St. Augustine?
— "Don't worry" by poet Mary Oliver, from Felicity, 2015, via OnBeing