This year, in a distinct shift, more people than ever -- including a wave of corporate, government and international interests -- are marking the day, which is being celebrated around the world Sunday.
Wal-Mart and Sam's Club stores set up first-time collection centers in the Sacramento area this weekend to recycle old computers, televisions and other electronics. Half a world away, the Chinese government has ordered its entire citizenry to participate in Earth Day.
And on Wednesday, California's Department of General Services held its first ever Earth Day celebration at the triangular ziggurat building in West Sacramento. The crowded event spilled onto the sun-dappled parkway along the Sacramento River, and featured a spectrum of displays ranging from "Dave the Solar Powered DJ" to private sector heavyweights such as PG&E and AT&T.
"In the past, Earth Day was something people paid passing attention to," said Bill Branch, spokesman for the Department of General Services. "In the last year or two, it has been stunning, the turnaround."
Branch and others attributed the shift to a notable increase in the public's understanding and concern about climate change and its threat to living organisms and the environment.
Two events have been particularly influential, according to John Harte, a professor of environmental science at the University of California, Berkeley: Hurricane Katrina, which "reminded us how we're at the mercy of nature," and former Vice President Al Gore's Oscar-winning film, "An Inconvenient Truth," which laid out global warming concerns.
"They galvanized the public to a state of caring and believing," said Harte, who was involved in the first Earth Day in 1970 as a Yale University professor. "We're seeing more involvement from everybody, including corporations."
On that first Earth Day 37 years ago, 20 million Americans gathered in communities from coast to coast to protest rampant pollution, toxic dumps and other outrages and to push for a cleaner, healthier environment.
That same year, the nation's emerging environmental consciousness led to the creation of the U.S. Environmental Protection Agency, as well as federal laws to protect air, water and wildlife.
Earth Day was born against the backdrop of anti-war protests and rebellion against the nation's political establishment. But people who embraced it came from all backgrounds, with a heavy base in the middle class, said Kathleen Rogers, president of the Earth Day Network, a Washington, D.C., nonprofit group that coordinates Earth Day globally.
"In those days, you had rivers that were burning and parts of Los Angeles where you couldn't see across the street because of the pollution," Rogers said. "It was a middle class outpouring of sentiment. It really wasn't a hippie thing as much as a health thing."
The annual event has grown steadily. Today, 175 countries have Earth Day on their calendars and 150,000 schools are participating in some way, Rogers said.
Over the years, in many places, Earth Day celebrations have carried the throwback "Earth Mother" feeling of the 1970s, with natural-foods snacks and tie-dyed T-shirts. Others have become highly organized action days when parks get cleaned, gas-guzzling cars are crushed, and children are immersed in the gospel of environmental stewardship.
Recently, many have noticed a shift in clientele with more and more businesses getting involved.
"In the past, Earth Day was celebrated more by the tree huggers, the hippie crowd," said Jon Myers, communications director for the California Integrated Waste Management Board, an agency dedicated to recycling and keeping waste out of landfills. "It really has surged and business is a big part of it now."
Just three years ago, Myers said, corporate entities showed little interest in participating in Earth Day events put on by the state government.
"This year I was approached by many more businesses wanting to get involved," Myers said. "I think they're looking at the bottom line and seeing that green is good for that bottom line."
Rogers agreed. She said some companies are genuinely motivated by concerns about the environment. Most, she said, are making more environmentally sensitive decisions -- such as using energy-efficient lighting systems or selling eco-friendly products -- because they can cut costs and improve sales and customer relations. She added that a number of businesses are in a "green-washing" mode, participating simply as a promotional tool.
At Wednesday's Department of General Services Earth Day event in West Sacramento, PG&E had a large display booth where people were given free energy-efficient light bulbs.
"Earth Day is much more mainstream now. The corporations have figured out they need to take more of a lead," said Nefretete Gardner, an account manager with PG&E working in the booth.
Wal-Mart Inc., based in Bentonville, Ark., decided to hold the electronic recycling collections in the Sacramento area as part of a growing effort to be an environmentally sensitive business. The reason: Customers want and expect it, said Wal-Mart spokeswoman Tara Raddohl.
"It's on the minds of our consumers," she said.
Sustainability, a buzzword in the environmental movement, also is a hot theme for businesses trying to succeed financially, Raddohl said. A year ago, the company decided to switch to more energy-efficient ceiling lighting in all stores -- a move that was good for the planet and also saves about $7 million a year.
"When you have the two benefits aligned, it makes a lot of sense," Raddohl said.
