10 Fascinating Facts About Earth Day

Every year on April 22, trees are planted, litter is cleaned up, and people call attention to the issues plaguing the planet—including climate change. In honor of the holiday, which is celebrating its 53nd anniversary in 2023, we’ve gathered together 10 fascinating facts about Earth Day.

1. Earth Day was created through the tireless efforts of Wisconsin Senator Gaylord Nelson and other environmentalists.

Senator Gaylord Nelson arrived in Washington in 1963 looking to make the fledgling conservation movement—sparked in part by Rachel Carson’s New York Times bestseller Silent Spring, which warned against the harmful effects of widespread pesticide use—a part of the national discourse. After witnessing the aftermath of an oil spill in California in 1969, Nelson doubled down on his commitment to raising environmental awareness. Drawing inspiration from the energetic anti-Vietnam War movement of the time, he enlisted support from both sides of the aisle, and on April 22, 1970, Earth Day was born.

2. John F. Kennedy played a role in early efforts to promote environmental conservation.

In 1963, Nelson proposed a “conservation tour” to Attorney General Robert F. Kennedy and Arthur Schlesinger, a member of President Kennedy’s “best and brightest” cabinet. Schlesinger privately endorsed the idea to the president, while Nelson wrote a direct memo to Kennedy, a bold move for a freshman senator from Wisconsin. Kennedy, however, was receptive, and on September 24, 1963, JFK embarked on a conservation-themed multi-state tour.

The president, accompanied by Secretary of the Interior Stewart Udall, Secretary of Agriculture Orville Freeman, as well as Nelson and a few additional senators, visited 11 states in five days. Nelson was disappointed in the president’s speeches, saying they “didn’t have much sweep or drama to them.” In addition, members of the press ignored environmental issues and instead focused their questions on the tense nuclear situation with the Soviet Union. It would be another seven years until Earth Day became a reality.

3. The first Earth Day saw 20 million Americans take to the streets.

The first Earth Day marked a strange combination of boisterous rallies and sober reflection on the state of the planet. Protests, demonstrations, fundraisers, nature walks, speeches, concerts, and every sort of civic gathering imaginable took place at colleges, VFW halls, public squares, and parks across the United States on April 22, 1970. Environmental crusaders found themselves thrust into the limelight, and pop culture icons like poet Allen Ginsberg were asked to speak on behalf of Mother Earth.

Some of the more colorful displays of the day included mock trials for polluting objects, like an old Chevrolet, which was sentenced to death by sledgehammer. (The car ultimately survived the beating and was donated to an art class.) In New York City, Earth Day celebrations effectively shut down parts of the city. Twenty thousand people packed into Union Square to see Paul Newman and hear a speech by Mayor John Lindsay, who arrived on an electric bus.

4. The date of Earth Day was specifically selected to mobilize college students.

To head up the Earth Day project, Senator Nelson enlisted Denis Hayes, then a graduate student at Harvard University. As national coordinator, Hayes recruited a staff of 85 energetic young environmental crusaders and grassroots organizers, along with thousands of field volunteers, in order to promote the fledgling holiday across the nation. The team knew that in order to gain the most traction, college students would need to play a central role, as they did in the Vietnam protests of the era. The date that Hayes selected for the first Earth Day was a calculated choice: April 22 on most college campuses falls right between spring break and final exams.

5. Earth Day faced criticism from the very beginning.

According to Grist, the first Earth Day faced staunch opposition from conservative groups like the John Birch Society, which claimed that the event was a thinly veiled attempt to honor the 100th anniversary of the birth of Vladimir Lenin. In addition to detractors on the far right of the political spectrum, bleeding-heart environmental crusaders weren’t satisfied, either. Earth Day, they claimed, simply served as a distraction from the more pressing social issues of the day. Journalist I.F. Stone said, “the country is slipping into a wider war in Southeast Asia and we’re sitting here talking about litterbugs.” Critics of the holiday also point to the trend of “greenwashing,” an attempt by corporations with poor environmental track records to appear conscientious if only once a year.

6. Earth Day sparked an unprecedented slate of environmental legislation.

With bipartisan support in Congress and thousands of civic demonstrations across the country, support for environmental reform in 1970 was undeniable. According to the EPA, “Public opinion polls indicate that a permanent change in national priorities followed Earth Day 1970. When polled in May 1971, 25 percent of the U.S. public declared protecting the environment to be an important goal, a 2500 percent increase over 1969.”

The 1970s saw the passage of the most comprehensive environmental legislation in U.S. history, including the Clean Air Act, the Water Quality Improvement Act, the Endangered Species Act, the Toxic Substances Control Act, and the Surface Mining Control and Reclamation Act. In addition, just eight months after the first Earth Day, Richard Nixon approved the creation of a new organization tasked with monitoring the nation’s natural assets: the Environmental Protection Agency.

7. Although it began as an American movement, Earth Day is now an international phenomenon.

In 1990, Earth Day expanded to include countries and peoples across the globe, with 200 million people in 141 nations getting involved. A decade later, at the turn of the new millennium, Earth Day shed light on the emerging clean energy movement and expanded its reach, spreading to 184 countries with the help of 5000 environmental organizations. Global activities included a massive traveling drum chain in the African nation of Gabon and an unprecedented gathering of hundreds of thousands of concerned citizens at the National Mall in Washington, D.C. According to Earth Day Network, after 40 years, more than 1 billion people participate in Earth Day activities, making it the largest secular civic event in the world.

8. Internationally, it's known as International Mother Earth Day.

Earth Day is now observed around the world, albeit under a different name: In 2009, the United Nations General Assembly decided to designate April 22 as International Mother Earth Day. The symbol of Mother Earth serves as a common metaphor and representation of our planet in many countries and cultures. In the United States, the holiday is still commonly referred to as Earth Day.

9. In 2009, NASA planted a historic “moon tree” to celebrate Earth Day.

During the Apollo 14 moon mission in 1971, astronaut Stuart Roosa brought with him hundreds of seeds from loblolly pine, sycamore, sweetgum, redwood, and Douglas fir trees. Roosa was a former smoke jumper for the U.S. Forest Service, and he transported the seeds in his personal effects as a tribute to his former employer. Roosa and his seeds orbited the moon 34 times in the command module Kitty Hawk. Scientists were curious whether exposure to the microgravity of space would impact the growth of these seeds when returned to Earth.

The experiment seemed like a lost cause when, during the post-mission decontamination process, the seed canisters broke open and the seeds were thought to be useless. However, most of the tree seeds were still fit for germination and were successfully planted and cultivated. These trees were planted around national monuments and in sites all over the country. After decades of growing side-by-side with their Earth cousins, the moon trees showed no differences at all. On Earth Day 2009, NASA, in partnership with the United States National Arboretum and American Forests, planted a second generation moon sycamore on the arboretum’s grounds in Washington, D.C.

10. The theme for Earth Day 2023 is “invest in our planet.”

Every year since Earth Day 2016, there has been a new theme attached to the holiday. In 2016, it was “Trees for the Earth,” followed by “Environmental and Climate Literacy” in 2017, “End Plastic Pollution” in 2018, and “Protect Our Species” in 2019. This year, Earth Day celebrants will adopt “Invest in Our Planet” as the guiding idea.

Organizers are hopeful that this will be a day to raise awareness of both the dangers of climate change and the opportunities people have to ensure a green future. Head to the Earth Day website find out more.

A version of this story ran in 2016; it has been updated for 2023.