How has Earth Day evolved?

­In 1970, protesting was practically a way of life in the United States. Young people and Hollywood stars, many of whom had been protesting the Vietnam War for years, took to Earth Day like fish to water. Back then, Earth Day wasn't the sedate celebration it is now. Some misguided young people actually smashed car windows for the cause, and many people walked the streets wearing gas masks.

But even those who weren't avid tree-hugging protesters showed up for that first Earth Day. Mainstream America got involved, too, after major newspapers started covering pollution-related health hazards on their front pages in preparation for the event.

At the time of Earth Day 1970, and the early years in general, it was the "conservation" movement, not the "environmental" movement. The focus was on preserving and protecting. Issues like air and water pollution, deforestation, nuclear testing and paving over parks were the big ones -- global warming wasn't yet on the docket.

Earth Day 1970 had a turnout few people expected. Around the United States and into Canada, 20 million people showed up at Earth Day rallies to draw attention to the cause and make the government take notice. It was a stunning success, especially considering the organizers' meager budget. With just $200,000, the Earth Day Network managed to set up rallies, speakers and teach-ins in places like Washington, D.C., New York City and Portland, all centered on the idea that people had to rethink their relationship with the Earth or suffer the consequences [source: Lewis].

Those early Earth Days were a measurable success, something that's pretty rare for a volunteer-driven protest. In December 1970, within seven months of the first Earth Day, the U.S. Environmental Protection Agency (EPA) was born. The Clean Air Act was broadened in 1970 and 1977, and the Endangered Species Act was passed in 1973. In 1980, Congress established Superfund to clean up hazardous waste sites. It was an incredible decade for environmental progress, and Earth Day 1970 played a big part in getting the ball rolling.

It's hard to replicate the excitement of the start of a movement that actually makes a difference. These days, Earth Day is less about protest and more about working toward particular goals.

It's also much, much bigger.

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­Things have changed since the 1970s. Communication is increasingly electronic. War is protested online. Petitions are e-signed. "Environmental action" entails throwing a newspaper in a recycling bin instead of in the trash. Earth Day is no different: You won't find many street riots at this year's Earth Day, thankfully. But you also won't find the electric atmosphere of 1970.

In the 21st century, "conservation" has become "the environment," and world governments are well aware of the issues at hand. Instead of focusing on protecting parks and eliminating pesticides in our food, the greater focus is on saving the future of the planet by curbing global warming, which could wipe out life as we know it.

Earth Day is a huge event. Major cities all over the world -- not just those in the United States and Canada -- host rallies, speeches, volunteer efforts like planting trees and cleaning up parks, and demonstrations at museums for everyone to take part in. Earth Day isn't just a day; it's a whole week, just in case people can't get out of work on April 22. What started in 1970 with an amazing 20 million people swelled to 200 million in 1990 and up to 500 million post-2000. The budget has expanded along with the number of attendees, now measuring well into the millions of dollars.

And along with big budgets comes big business. Saving the environment has become a consumer craze, and at a 21st century Earth Day, you'll find all sorts of "green" products available for purchase and free trial. Care for a snack? Try the chocolate bar that comes in recyclable packaging. Or maybe pick up a package of sustainable wood-fiber-filled baby diapers, or a no-animal-testing sunscreen, nontoxic spray cleaner, an entry form for a Prius giveaway or a cloth grocery bag for your shopping.

­The feeling of Earth Day may have changed in the last 40 years, but the motivation is still the same: To get legislators and civilians alike to take action against environmental destruction. This year, when you attend an Earth Day celebration in your area, just remember to bring your grocery tote -- there probably won't be many plastic bags available for carrying your stuff.

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