A short course in planetary time, for planetary survival — This is less of a blog post, and more of a howl. The planetary climate clock, in human time Let’s start by some human and planetary timescales. I don’t know why we don’t learn them in grade school (I never learned them at all). But they matter. And let’s represent them visually, in a stark, plain way. “_” : this is our unit of time, and it’s 1000 years long.