Each year, Earth Day -- April 22 -- marks the anniversary of what many consider the birth of the modern environmental movement in 1970.

Each year, Earth Day -- April 22 -- marks the anniversary of what many consider the birth of the modern environmental movement in 1970.

The height of hippie and flower-child culture in the United States, 1970 brought the death of Jimi Hendrix, the last Beatles album, and Simon & Garfunkel’s “Bridge Over Troubled Water”. Protest was the order of the day, but saving the planet was not the cause. War raged in Vietnam, and students nationwide increasingly opposed it.

At the time, Americans were slurping leaded gas through massive V8 sedans. Industry belched out smoke and sludge with little fear of legal consequences or bad press. Air pollution was commonly accepted as the smell of prosperity. “Environment” was a word that appeared more often in spelling bees than on the evening news.  Although mainstream America remained oblivious to environmental concerns, the stage had been set for change by the publication of Rachel Carson's New York Times bestseller Silent Spring in 1962.  The book represented a watershed moment for the modern environmental movement, selling more than 500,000 copies in 24 countries and, up until that moment, more than any other person, Ms. Carson raised public awareness and concern for living organisms, the environment and public health.

Earth Day 1970 capitalized on the emerging consciousness, channeling the energy of the anti-war protest movement and putting environmental concerns front and center.

The idea came to Earth Day founder Gaylord Nelson, then a U.S. Senator from Wisconsin, after witnessing the ravages of the 1969 massive oil spill in Santa Barbara, California. Inspired by the student anti-war movement, he realized that if he could infuse that energy with an emerging public consciousness about air and water pollution, it would force environmental protection onto the national political agenda. Senator Nelson announced the idea for a “national teach-in on the environment” to the national media; persuaded Pete McCloskey, a conservation-minded Republican Congressman, to serve as his co-chair; and recruited Denis Hayes as national coordinator. Hayes built a national staff of 85 to promote events across the land.

As a result, on the 22nd of April, 20 million Americans took to the streets, parks, and auditoriums to demonstrate for a healthy, sustainable environment in massive coast-to-coast rallies. Thousands of colleges and universities organized protests against the deterioration of the environment. Groups that had been fighting against oil spills, polluting factories and power plants, raw sewage, toxic dumps, pesticides, freeways, the loss of wilderness, and the extinction of wildlife suddenly realized they shared common values.

Earth Day 1970 achieved a rare political alignment, enlisting support from Republicans and Democrats, rich and poor, city slickers and farmers, tycoons and labor leaders. The first Earth Day led to the creation of the United States Environmental Protection Agency and the passage of the Clean Air, Clean Water, and Endangered Species Acts. "It was a gamble," Gaylord recalled, "but it worked."

As 1990 approached, a group of environmental leaders asked Denis Hayes to organize another big campaign. This time, Earth Day went global, mobilizing 200 million people in 141 countries and lifting environmental issues onto the world stage. Earth Day 1990 gave a huge boost to recycling efforts worldwide and helped pave the way for the 1992 United Nations Earth Summit in Rio de Janeiro. It also prompted President Bill Clinton to award Senator Nelson the Presidential Medal of Freedom (1995) -- the highest honor given to civilians in the United States -- for his role as Earth Day founder.

As the millennium approached, Hayes agreed to spearhead another campaign, this time focused on global warming and a push for clean energy. With 5,000 environmental groups in a record 184 countries reaching out to hundreds of millions of people, Earth Day 2000 combined the big-picture feistiness of the first Earth Day with the internatithe environmental community. Climate change deniers, well-funded oil lobbyists, reticent politicians, a disinterested public, and a divided environmental community all contributed to a strong narrative that overshadowed the cause of progress and change. In spite of the challenge, for its 40th anniversary, Earth Donal grassroots activism of Earth Day 1990. It used the Internet to organize activists, but also featured a talking drum chain that traveled from village to village in Gabon, Africa, and hundreds of thousands of people gathered on the National Mall in Washington, DC. Earth Day 2000 sent world leaders the loud and clear message that citizens around the world wanted quick and decisive action on clean energy.

Much like 1970, Earth Day 2010 came at a time of great challenge for ay Network reestablished Earth Day as a powerful focal point around which people could demonstrate their commitment. Earth Day Network brought 225,000 people to the National Mall for a Climate Rally, amassed 40 million environmental service actions toward its 2012 goal of A Billion Acts of Green®, launched an international, 1-million tree planting initiative with Avatar director James Cameron and tripled its online base to over 900,000 community members.

The fight for a clean environment continues in a climate of increasing urgency, as the ravages of climate change become more manifest every day. We invite you to be a part of Earth Day and help write many more victories and successes into our history. Discover energy you didn't even know you had. Feel it rumble through the grassroots under your feet and the technology at your fingertips. Channel it into building a clean, healthy, diverse world for generations to come.