After 50 years, the Earth Day mantra remains: Act or die. 

The world has changed since the first Earth Day in 1970. That change has cheapened our odds of survival. Perhaps it was the 1969 explosion of an offshore rig that spilled  100,000 barrels of crude oil onto beaches near Santa Barbara, California. Or perhaps it was the acrid smog choking major cities like New York and Los Angeles while the Cuyahoga River, north of Cleveland caught fire because of toxic chemicals and debris.  By the late 1960s, environmental concern began to shape the American imagination. Sensitive to the growing public’s…