'If the environment is a fad, then it's going to be our last fad," warned Denis Hayes at the first Earth Day on April 22, 1970, having given up his own graduate studies at Harvard only months before to organize this historic event."We are building a movement, a movement with a broad base, a movement which transcends political boundaries. It is a movement that values people more than technology, people more than political boundaries, people more than profit," said Hayes, now a 61-year-old advocate of solar energy and environmental conservation. Since that spring day in 1970, 35 Earth Days have passed, as well as 20 International Earth Days.