Obviously, some time in the past would have been better, but we've missed that already, so "now" is the best remaining option. When we're currently on a course

Obviously, some time in the past would have been better, but we've missed that already, so "now" is the best remaining option. When we're currently on a course that is degrading the environment of the entire planet for all of us, the sooner we begin to alter that course, the better.