In fall 1968, the first Whole Earth Catalog reproduced on its cover a NASA composite photograph never before seen in public — Earth floating in the arid blackness of space, beautifully blue and alone and fragile.

In January 1969, a runaway oil rig blowout in the Santa Barbara Channel in California devastated local wildlife and alarmed the nation with images of oil-soaked beaches, seabirds and seals. Then in June, the Cuyahoga River, an industrial sewer running through downtown Cleveland, caught fire. In fact the river had combusted many times before, and some of these fires were bigger, but Time magazine reported on this one and the story went national.

In 1969, U.S. Sen. Gaylord Nelson of Wisconsin, flying back to Washington from an inspection of the California spill, read an article about “teach-ins” created by activists opposed to the Vietnam War and thought: Why not create a teaching event for the environment? He hired young organizer Denis Hayes to run a national environmental teach-in out of his D.C. office. He and a handful of staff organized what became, on April 22, 1970, an estimated 20 million people taking action for what was by then firmly labeled “Earth Day.”

Citizens and their representatives in Washington were galvanized, the policy results transformative. President Richard Nixon deserves credit for proposing, on July 9, 1970, the Environmental Protection Agency, and later signing pioneering environmental legislation protecting clean air and water, although he did so in part to outflank potential Democratic opponent Sen. Henry Martin “Scoop” Jackson of Washington — both were consummate politicians who heard the citizenry’s howl and responded.

This April 22, the 50th anniversary of what is now the largest secular holiday worldwide, it is useful to recall these founding stories: an inspirational image of fragile earth, omnipresent now as the “big blue marble” photograph taken from Apollo 17; fossil-fueled calamities, now all too familiar; Earth Day’s organized citizen action, and determined political response.

The 50th anniversary will be the strangest, as the COVID-19 pandemic will require most citizens to demonstrate at home and online. Yet this is an all-hands-on-deck moment, requiring the urgent, game-changing response COVID-19 received. This year is forecast to be the hottest on record, after 2019’s frightening and costly fires, floods and storms that devastated the Australian bush and Midwestern farms. The melting of the ice caps and glaciers accelerates as temperatures soar, a record 64.9 degrees Fahrenheit recorded in Antarctica on Feb. 8, the same temperature as Los Angeles that day. Already 90 American cities experience some flooding, while officials in low-lying cities like Manila consider how to move.

Yet good news is also plentiful. Wind and solar energy are booming at a scale and cost unimaginable even a few years ago, with electric cars, buses, trucks and charging stations rolling out fast around the world. In September, the Los Angeles Department of Water and Power accepted a bid for electricity produced by renewable energy, including storage capacity for round-the-clock supply, at 2 cents a kilowatt-hour, far cheaper than any other source. And Germany, Denmark and the Netherlands are building an island to house 7,000 wind turbines to provide electricity for 80 million Europeans. The green-energy revolution is now.

Meanwhile, the global fossil-fuel industry is reeling from falling demand, a price war and withdrawal of the global finance system from further investment. The fossil-fuel divestment movement begun in 2012 has surpassed $12 trillion in public commitments to divest from fossil-fuel stocks and investments. And in January the CEO of BlackRock, the world’s largest financial firm, wrote to global CEOs that his company will be considering climate change in investment decisions: “I believe we are on the edge of a fundamental reshaping of finance.”

Still, none of these changes is moving remotely fast enough given the pandemic of fossil-energy excess. On a typical day, the global economy still dumps the heat equivalent of 40,000 Hiroshima atomic bombs into the atmosphere.

Yet the Trump administration, abetted by coal-state Senate Majority Leader Mitch McConnell and other fossil-fueled representatives and talk show advisers who reflexively denied the severity of COVID-19 just as they derided the climate “hoax,” daily unravels not only longstanding environmental protections but subverts any responsible clean climate policy, most recently cutting clean car-mileage standards against the wishes of much of the auto industry.

But it is fair to remember that, 50 years ago, the nation was also facing a wide swath of environmental calamities and did not despair. Citizens raised hell, took action, changed practices and elected leaders who enacted strong, effective laws that produced dramatic improvement in health and quality of life, all without the economic calamity forecast by naysayers — in fact, with major economic benefits. Modern industrial America has blue skies and clean lakes and rivers not by accident but by design, a legacy of 50 years of Earth Days.

Today’s global response to the COVID-19 pandemic offers a valuable lesson in concerted action. The formerly unimaginable $2.2 trillion in federal funding is an example of what support the climate crisis also calls for. Meanwhile, the air over China is temporarily clear and breathable due to COVID-19’s forced reduction in fossil-energy intensity.

Will that lesson be learned? Or after the pandemic passes will fossil-fueled economies again fire up all cylinders of their 19th-century internal combustion machine, leaving in its exhaust today’s vision of a cleaner, safer planet?

“There is no Planet B” is a phrase that has appeared spontaneously on placards waved at climate crisis demonstrations around the world and is now the title of a book. Its wisdom is twofold. Earth, that “beautiful blue marble” floating in space, has the water, air and renewable energy we need. And there is a viable green economic future.

As the nation fights through the COVID-19 pandemic toward the November elections, voters need to remember two facts. When asked in a Democratic debate if climate change is an existential crisis, every candidate answered yes without hesitation. Meanwhile, the Trump administration and its allies, including Russia and Saudi Arabia, do everything they can to prop up the struggling fossil-fuel industry while undoing regulations aimed at curbing the climate crisis. Planet Earth is on the ballot this November.

James P. Lenfestey is a former editorial writer for the Star Tribune covering education, energy and the environment.