By Published: April 18, 2024

CU Boulder professors explain Earth Day’s history, impact, what it’s become and if it’s still relevant


If you were at the University of Colorado Boulder in April 1970, you were likely aware―very aware―of the first Earth Day on April 22. CU Boulder was all in and almost stretched the day into a full week, kicking things off on April 18 when the campus was dotted with green flags and abuzz with special events, speeches, films, symposiums, rap sessions and panels.

CU Boulder was just one of about 1,500 universities celebrating Earth Day, not to mention 20 million Americans and more than 10,000 cities, churches and other organizations, says Paul Sutter, a CU professor of environmental history.

That first Earth Day went viral long before viral was cool. No social media, no email blasts, no group texts. Just TV, radio, word of mouth and, in Boulder, an old-fashioned paper-and-ink brochure listing the scheduled events.

“One of the remarkable things is that Earth Day came out of nowhere and was organized quickly, bringing together large numbers of activists who had worked separately before and had not put a name to their movement yet,” Sutter says.

Paul Sutter and Steve Vanderheiden

CU Boulder scholars Paul Sutter (left) and Steve Vanderheiden have studied Earth Day's history and impact.

“Earth Day was also decentralized, which meant that it manifested itself in different ways in different places. This was one key to its success. In many ways, we’ve forgotten how powerful and radical these events were. Organizing these events helped to democratize environmentalism.”

So what led to that first Earth Day? And have subsequent Earth Days had the same impact?

Some, including Sutter, say the time was right and argue that even though it sprouted quickly, there were forces at work decades before its birth.  

“Americans emerged from WWII concerned about the destructiveness of the war and the state of the global environment―particularly the relationship between population growth and natural resources,” Sutter says. “Early postwar environmental concern was decidedly global.”

And there was worry about the atomic bomb and nuclear technology. “The first detonation of an atomic bomb … was a watershed moment in the nation’s environmental history, and postwar antinuclear activism culminated with the Nuclear Test Ban Treaty of 1963,” Sutter says.

Many cite Rachel Carson’s book on environmental science, Silent Spring, as an added spark as well.

Another factor: The space program, which allowed humans to view Earth from space for the first time. Sutter says that sight gave people “a sense of the planet’s finitude and limits.”

Still relevant?

As successful as that first Earth Day proved to be, after more than a half century, some question whether it’s still relevant, and ask if there’s something else that could make a bigger difference.

Steve Vanderheiden, a CU Boulder professor of political science and environmental studies, says anything that’s been observed annually since 1970 is “bound to have diminishing returns” over time, and that today’s iteration “will be less consequential” than the first one.

One of the remarkable things is that Earth Day came out of nowhere and was organized quickly, bringing together large numbers of activists who had worked separately before and had not put a name to their movement yet.”

“I don't mean to suggest that there isn't still a role for what Earth Day has become―an occasion to teach about environmental issues or hold events where people reaffirm the importance of environmental protection―but rather that we shouldn't expect it to make much of a difference in public opinion or to build momentum for legislation, which we still need,” Vanderheiden says.

“Those goals are now better served by more oppositional forms of political organization and expression that are more willing or able to challenge the status quo.”

While Vanderheiden says that the original Earth Day was “a powerful focusing event” for the U.S. environmental movement, he sees subsequent Earth Days as having made “relatively little difference,” and that any of the past 40 Earth Days have not swayed public opinion on most environmental issues.

“Part of this is a function of the original Earth Day [that was] intended as a consciousness-raising event, for which it was wildly successful. Consciousness now having already been raised about such issues, these later iterations have less potential to accomplish the same objective.”

Vanderheiden adds that Earth Day has also not evolved to reflect activism or resistance. “That might make it too threatening to the status quo to continue enjoying the wide but shallow support that it now receives. In a way, Earth Day has … maintained its popularity because it doesn't really challenge anything anymore. It’s somewhat like how we still celebrate May Day but almost never with much of its original critical content.”

Interested in learning more about Earth Day? Sutter recommends Adam Rome’s The Genius of Earth Day.

Top image: The partly-illuminated Earth rising over the lunar horizon as recorded by Apolo 11; the Earth is approximately 400,000 km away. (Photo: NASA)


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