Carbon Dioxide: Our Newest Pollutant‪.‬

I. WHY CARBON DIOXIDE? It was my great pleasure to come to Suffolk University Law School to join the ranks of the many distinguished individuals who have delivered the Donahue Lecture. The topic of this lecture is the simple chemical, carbon dioxide, which is, now officially, our newest pollutant. The first question to ask is why I chose this particular title for carbon dioxide, a substance that predates the industrial revolution and is, in limited quantities at least, necessary for the survival of life as we know it on this planet. The answer relates to complexities that lie beyond my control under the peculiar statutory framework for dealing with pollutants under the Clean Air Act (CAA), which is administered by the Environmental Protection Agency (EPA). Pollutants must be registered under the CAA, and there has been a huge dispute--which I shall explain later on--about whether or not carbon dioxide should be registered as such under the Act. (2) After much internal debate, the Bush Administration said no. The states, led by Massachusetts, thought that the answer ought to have been yes. They forced the issue to the Supreme Court, which held in Massachusetts v. EPA (3) that, although the EPA was not necessarily bound to make that "endangerment" determination, it was nonetheless authorized to do so because carbon dioxide fell within the CAA's definition of an "air pollutant." (4) Under the CAA, an "air pollutant" is "any physical [or] chemical ... substance or matter which is emitted into or otherwise enters the ambient air." (5)