crusade to join. joi >> these two books were have you mental in the creation of eartt day. >> it was on april 22, 1970. that same date happens to be the birth date of lenon. a lot of folks say that was a coincident but there are a lot of radical environmentists at the time thatenvi thought this s very clever, it's an in-your-face to can'tism. >> and 20 million people participated in the first earth day across the country. so the environmental his steer yeah began. fear of global cooling startedd in the 1970s. now a cover story in the 1975 issue of news week magazineweek elevated the to a national level. it would more of into global warning as the science indicated that the temperatures wered t rising and not falling. but in movement with mesh with politich leaving environmentists as a cross-roads. patrick moore was one of the mounding members of greenpeace. >> around the mid-1980's theveme