It‘s a day to celebrate， a time to educate， and a way to make a difference. Earth day was first observed on April 22， 1970. the tradition began in the united states and is now an international focal point for people who are concemed about the environment.
Imagine a time before the Clean Air Act， the Clean Water Act， the Endangered Species act， and even the environmental Protection Agency. Hot topics of the time were industrial pollution， nuclear accidents， oil dependency， pesticides， and a vanity of social issues. However，olicymakers were not yet acting on many important environmental problems.
Earth day grew ort of grassroots action and institutional support. Student leader Denis Hayes and Wisconsin Senatour Gaylord Nelson were two key organizers for the firwt event. Over 20 million concerned citizens rallied for clean air and water. College students were a major force in the campaign， although participants of all ages were involved. Still， we cannot really credit a handful of individuals for the success of Earth Day. After all， a major message of Earth Day is that every single person has an important role in the environment.
The first Earth Day was very successful， inspiring the passage of congressional protection for air， water， and endangered species. Momentum from the demonstration also fueled the formation of the Environmental Protection Agency.
Thirty years later， the focus has changed but the urgency remains the same. Due to increasing amounts of scientific evidence that fossil fuels are changing the global climate， the theme for Earth Day 2000 is Clean Energy. The four major goals of Earth Day 2000 are clean cars， clean power， clean air， and clean investments.
1. April 22nd， 2000 is the ____ years‘ anniversary of the Earth Day.