In this first-ever national debate over a pipeline, the arguments are getting heated. So maybe it's a good time to take a couple of steps back to remind ourselves why we care. Just why is this pipeline such a big deal? That question has several answers, but they start with this: It's not about the pipe. It's about what the pipe would carry.
Although he has struggled with the paradox of reducing carbon pollution while promoting a dirty "all of the above" energy policy, Obama already has more than enough evidence to reject this pipeline based solely on its effect on climate disruption. But even though this debate has centered on climate, that is only part of what's at stake.