From the YouTube description:
For this year's Earth Day celebration, Reason.tv is proud to present "The Top Five Environmental Disasters that Didn't Happen." The environmental movement began in 1962 when Rachel Carson published her best-selling book Silent Spring. And ever since, chicken littles have warned us about imminent environmental disasters that ultimately didn't happen.If you're wondering what environmental disaster made it into the top spot I'll give you an indirect hint by suggesting that you read this book.
We all worried needlessly about acid rain, expanding deserts and global cooling, but these failed predictions weren't quite dire enough to make our list. To find out which prophecies of doom did make our list, you'll need to watch Reason.tv's "Top Five Environmental Disasters that Didn't Happen."