If pop culture has taught us anything – and these days, it has probably taught us all too much – it is that as a person enters their fourth or fifth decade they experience something called a mid-life crisis. Sports cars, trophy spouses, and comically bad wardrobe and hairstyle choices have been known to follow.
Now the Environmental Protection Agency is entering its fourth decade, turning 40 years old this week, and is joined by a landmark piece of environmental legislation, the Clean Air Act.