The Day the Earth Moved: On the fiftieth anniversary of Earth Day; environmental activism has never been more important.

• Author: Nelson, Tia

I was almost fourteen years old on April 22, 1970, the first Earth Day. I spent the day picking up trash at my junior high school, along with other young people.

My father, the late Wisconsin U.S. Senator Gaylord Nelson, came up with the idea of Earth Day. He said its purpose was to "get a nationwide demonstration of concern for the environment so large that it would shake the political establishment out of its lethargy."

Twenty million people responded to his call to action that day. In doing so, they demonstrated the power of individual action to change the course of history and help build a brighter future.

That first Earth Day ended up sparking a global movement that was successful beyond my father's wildest dreams. It united people across political lines to take concrete steps toward a healthier planet, including passage of the Clean Air Act and the Clean Water Act and the creation of the Environmental Protection Agency.

Now, as we approach the fiftieth anniversary of that first Earth Day, the planet is in the throes of a sweeping pandemic that requires an unprecedented level of global commitment and cooperation. It is a moment that could have a profound impact on humankind's response to the existential threat posed by climate change.

The disruption brought by the coronavirus is as great but much more sudden than that of climate change. Perhaps we will, in the spirit of Earth Day, learn that we are able to make the collective sacrifices required to combat a common threat.

Even before the COVID-19 outbreak, the modern environmental movement was energized. Yet when it comes to my father's original vision of an inclusive, bipartisan environmental movement rooted in social justice, we still have work to do. Today, as we face the most significant health and environmental challenges of all time, it's critical that we take stock of the problems and opportunities they bring.

"Our goal is not just an environment of clean air and water and scenic beauty" my father said on Earth Day 1970 during his speech in Denver. "The objective is an environment of decency...