世界地球日的英文是：Earth Day

Earth Day was first observed in Spring of1970. An estimated20 million people nationwide attended festivities out of which came the largest grassroots environmental movement in . history, and the impetus for national legislation like the Clean Air and Clean Water Acts. By the twentieth anniversary of that event, April22,1990, more than200 million people in141countries participated in Earth Day celebrations.

Former . Senator Gaylord Nelson, Earth Day"s co-founder, modeled Earth Day on anti-Vietnam War demonstrations, called "teach-ins," that were common on college campuses. "At a conference in Seattle in September1969, I announced that in the spring of1970 there would be a nationwide grassroots demonstration on behalf of the environment," says Nelson. "The response was electric. Telegrams, letters, and telephone inquiries poured in from all across the country." As many as20 million Americans participated in environmental rallies, demonstrations and other activities in the1970 Earth Day.

Since the first Earth Day, however, the environmental movement has increasingly transformed itself from a largely grassroots, citizen crusade to a professionally-organized, established special interest.