Originally published on Legal Planet

There's already been a lot written in the aftermath of Justice Stevens's death, including Ann Carlson's excellent Legal Planet post earlier this week. I'd like to add something about an aspect of his jurisprudence that had great relevance to environmental law: his belief in the rule of law, and specifically, in the duty of both the judiciary and the executive branch to respect and implement congressional mandates.

This stance was evident in Justice Stevens's decision in Massachusetts v. EPA, probably the most important environmental case that Supreme Court has ever decided. The Bush administration refused to regulate greenhouse gases under the Clean Air Act. But the statute was very clear. It defined air pollutants as any substance emitted into the air, and it required regulation of such pollutants whenever they endanger human health or welfare. The Bush administration also argued that international negotiations would be a more fruitful way of addressing the problem. Apart from the fact that this was clearly a pretext – Bush had shown no interest in brokering an international agreement – it had nothing to do with the only relevant issue under the statute: what the science had to say about the dangers …