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14 Earth Day Facts You Should Know

Our planet is in peril—and it's an Earth Day fact that this day was created 51 years ago to raise awareness about the importance of taking action now.

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people gather in a park in New York City with banners to celebrate the first Earth Day, April 20, 1970Santi Visalli/Getty Images

The very first Earth Day

Earth Day first came into being on April 22, 1970, followed in 1972 by World Environment Day. It has been celebrated ever since, slowly but surely picking up steam as more and more people have recognized the importance of taking care of the earth.

Indian schoolchildren take part in a parade to mark Earth Day in New Delhi, 22 April 2007.MANAN VATSYAYANA/Getty Images

Earth Day is now a global event

Earth Day remained a grassroots affair for 20 years, before going global and spreading out to 140 countries in 1990. It’s now celebrated in over 190 countries, with an estimated 1 billion people the world over participating each year. These important Earth Day facts along with these Earth Day quotes will motivate you to do your part.

Portrait of American politician US Senator Gaylord Nelson (1916 - 2005), founder of Earth Day, as he poses in Rock Creek Park, Washington DC, January 1990.Janet Fries/Getty Images

Earth Day was the brainchild of Wisconsin Governor Gaylord Nelson

Gaylord Nelson, a two-term governor of Wisconsin (1958 to 1962), was responsible for focusing his state’s environmental policy, establishing a single Department of Resource Development, a Youth Conservation Corps, and setting aside $50 million to buy land and convert it to parks and wilderness areas during the years he was in office. This earned him the nickname “Conservation Governor.” Nelson was then elected a U.S. senator, where he became known as a champion for the earth, asserting that “Environment is all of America and its problems. It is rats in the ghetto. It is a hungry child in a land of affluence. It is housing not worthy of the name; neighborhoods not fit to inhabit.” Test your eco-smarts with our Earth Day quiz.

Preparations for Earth Day Teach - In Start; Readying a display booth at Currigan Hall are, from left. Charles Petersen, project officer, and Ed Harris and Bob Page, recreation resource specialists with the U.S. Department of the Interior Bureau of Outdoor Recreation; April 1970.Millard Smith/Getty Images

Earth Day started as a teach-in for the environment

Frustrated by a lack of support for environmental policy among his fellow senators, but inspired by the various youth movements of the ’60s that were pushing hard for meaningful societal change, Nelson devised the idea of a teach-in for the environment in 1969. The plan was to drum up public support for the nascent environmental movement, with an eye toward engendering the political will to make change. Nelson’s idea was so popular that he had to hire an 85-person team to get the first Earth Day off the ground.

the skyline of downtown Los Angeles including the city hall (center) and the United States Courthouse (left), and Hall of Justice (right) shrouded and obscured by smog, a form of industrial and automotive air pollution particularly problematic in the area during the mid 20th Century, 1956.American Stock Archive/Getty Images

Even back in the 1950s and 1960s, the world needed Earth Day

We may think of man-made climate change as a recent development, but it’s a critical Earth Day fact: Even decades ago, the country was a polluted place in need of help. Public lands were dilapidated, factories were free to dump toxins into our waters, and industries could churn out pollutants into our air without regulation. As a result, species began collapsing—oysters, for example, were gone from New York Harbor by the early 20th century. Around the time of the first Earth Day in 1970, people were starting to realize that pollution and toxic waste could lead to cancer and other serious health issues.

Thousands of young people stretched out over a mile walking along a closed river drive during a Philadelphia Earth Walk, April 22, 1970.Bettmann/Getty Images

10 percent of the U.S. population celebrated the first Earth Day

Nelson chose this date in the third week of April to appeal to his core demographic—students—and April 22 fell between their spring break and final exams. Enormous, inspirational, rallies were held all over the country, with 20 million people—10 percent of the U.S. population at that time—taking to the streets. These 50 powerful photos prove the Earth still needs our help.

A flag with the EPA logo flies in front of the Environmental Protection Agency on Tuesday, Jan. 1, 2019.Bill Clark/Getty Images

The first Earth Day spurred immediate action

The impact of that first Earth Day was immediate and profound; by December of 1970, President Richard Nixon had established the Environmental Protection Agency and the Clean Air Act was devised and passed that year. Swiftly on their heels came the Clean Water Act, the Endangered Species Act, the Resource Conservation and Recovery Act, the Federal Environmental Pesticide Control Act, and the Federal Land Policy and Management Act, among other critical pieces of legislation.

Circle of people at Earth Day CeremonyJoe Sohm/Visions of America/Getty Images

Earth Day went global in 1990

On the occasion of its 20th birthday in 1990, Earth Day’s organizers decided the time had come to take the movement global— 200 million people in 141 countries participated. The impacts of that day were enormous: it kicked off massive initiatives to recycle and paved the way for the 1992 United Nations Earth Summit in Rio de Janeiro. Check out these at-home Earth Day activities for kids you can arrange this year.

The United Nations logo on the back wall of the General Assembly Hall of the United Nations is seen from the floor May 12, 2006 at the United Nations headquarters in New York.Chris Hondros/Getty Images

The United Nations joined the celebration in 2000

By the time of Earth Day’s 30th anniversary, coinciding with a brand new millennium, Earth Day was being announced by the United Nations. “At the end of the 20th and the dawn of the 21st century, the human species had entered a new era where the nature of the entire planet was being fundamentally changed,” the international organization said in a statement about the day. “Humankind was facing epidemics, massive holes in the ozone layer, and the change in global climate. In that context, it was necessary to have an informed citizenry, which would take a leadership role in pulling the political and economic forces in the right direction. It was time for a formidable shift, both at high and low levels. In the year 2000, a decision had been made to focus on energy and climate change.”

digital model of the earthEDUARD MUZHEVSKYI/SCIENCE PHOTO LIBRARY/Getty Images

Earth Day goes virtual

The year 2000 also marked the era when the Internet helped spread the message of the need for strong environmental policy far and wide. Being virtually connected allowed 5,000 environmental groups to find each other and coordinate their messaging. It allowed people from 184 countries to join in marches and demonstrations and acts of organizing.

group of people's hands holding plants growing out of soil; planting trees for Earth Day conceptPeopleImages/Getty Images

Each year’s celebration has a theme

In 2016, the theme of Earth Day was “Trees for the Earth” with the goal of planting 7.8 million trees in time for Earth Day’s 50th anniversary in 2020. Here’s the big difference between weather and climate (and 10 other nature words everyone gets wrong).

Marchers head down Constitution Avenue toward the U.S. Capital Building during the Earth Day March for Science on April 22, 2017 in Washington, DC.Paul Morigi/Getty Images

Scientists lend their voices and support

Although the March for Science began as its own separate movement in February 2017, by April of that year, it joined Earth Day marches and celebrations in Washington, D.C., and 360 other cities. While the group’s aims of protecting science from “manipulation by special interests,” and opposing policies that “threaten to further restrict scientists’ ability to research and communicate their findings” are not solely related to the health of the Earth, they do go hand in hand with supporting environmentalists and earth scientists. Learn the difference between climate change and global warming.

Pakistani representatives of non governmental orgainzations gather during the Earth Day ceremony in Karachi, 22 April 2007.RIZWAN TABASSUM/Getty Images

Earth Day is still a grass-roots movement

While yes, Earth Day has become a global phenomenon, it still counts on local initiatives to demonstrate the power of change on a smaller but still-critical level. A few examples: In 2015, Tanzania led efforts to protect the Usambara Mountains, including teaching residents about how to conserve water, while in Puerto Rico, celebrations centered around the establishment of a new eco-park and an initiative began to keep the island trash free for 100 days. Learn more about Kenya’s strict ban on plastic bags.

Street painters depict colorful scenes of nature in Manila's Makati financial district on May 4, 2008 in a special city-wide "Earth Day" celebration.JAY DIRECTO/Getty Images

There’s still a lot of work that needs to be done

As Earth Day’s founding organization reports, all this interest and action has not been without its counterpoint from climate change deniers, lobbyists, politicians, and more. Despite the challenges, it’s an Earth Day fact that the day is considered “the largest secular observance in the world.” That is no small feat and, although corporate interests continue to plague meaningful efforts at policy change to make the world more livable, the fact that by 2010 Earth Day had coordinated with 75,000 global partners—and that number has only grown since then—is cause for celebration. Find out 10 things the U.S. doesn’t recycle but other countries do.

a low sun shines it's rays through trees in a forest in autumnJeff Pudlinski/500px/Getty Images

The theme of Earth Day 2021 is…

The theme for this year’s Earth Day is “Restore the Earth.” It’s dedicated to focusing on “natural processes, emerging green technologies, and innovative thinking that can restore the world’s ecosystems,” reports These countries are replacing plastic in the most brilliant ways.

Lela Nargi
Lela Nargi is a veteran journalist covering science, sustainability, climate, and agriculture for Readers Digest, Washington Post, Sierra, NPR, The Counter, JSTOR Daily, and many other outlets. She also writes about science for kids. You can follow her on Twitter @LelaNargi.

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