Neither of us imagined that getting a Ph.D. in science would turn us into climate activists, too.

As scientists and as a couple in our twenties, it's been excruciating to watch the Trump administration's unrelenting attacks on climate science and our generation's future. Knowing that policy decisions made over the next four years could impact the lives of hundreds of generations to come, we're more determined than ever to do not only our best work as scientists, but our best activism as citizens.

On April 29, we'll stand up for climate science, justice, and democracy in the People's Climate March. If you're appalled at the Trump administration's anti-climate agenda, we hope you'll join us.

Part of what brought the two of us together was our shared love of science, and our belief in its power to make the world a better place. We both wanted to help tackle climate change — one of us, by understanding the problem better; the other, by engineering solutions.

"With this fear came a realization that doing science alone was not enough."

But the more we learned, the more afraid we became. On humanity's current path, we're likely headed for more than 4 degrees Celsius of global warming in our lifetimes. Along that path lies the extinction of the Great Barrier Reef. Mass refugee crises catalyzed by unprecedented droughts (Syria is a case in point). Submerged island nations and coastal cities — among them, Bangkok, the hometown for one of us, and Boston, our home for the past six years. The possibility of a 4-degree world has forced us to grapple with whether or not to have children.

I showed the results of aerial surveys of #bleaching on the #GreatBarrierReef to my students, And then we wept. pic.twitter.com/bry5cMmzdn — Terry Hughes (@ProfTerryHughes) April 19, 2016

With this fear came a realization that doing science alone was not enough. Not when global greenhouse gas emissions must start falling, now, faster than they have risen for the past 160 years. Not when the fossil fuel industry spends trillions of dollars looking for new reserves they know can never be burned. Not when political ideologues and fossil fuel interests spend hundreds of millions of dollars blocking meaningful climate legislation and funding disinformation campaigns to confuse the public and attack climate scientists — a 30-year-old tactic that continues today.

Compelled to act

Bit by bit, we began taking part in collective actions, determining that this was key to tackling such a systemic problem. It was a reluctant decision for a pair of introverted scientists with no experience in activism. But as Nobel Laureate and scientist-advocate Sherry Rowland once asked, "What's the use of having developed a science well enough to make predictions if, in the end, all we're willing to do is stand around and wait for them to come true?"

And so we joined the fossil fuel divestment campaigns at Harvard and MIT. A few months later, we went to our first protest, where 398 young demonstrators chained their wrists to the White House fence in an act of civil disobedience against the Keystone XL oil pipeline. They were all arrested, one by one. Their courage brought shame to our hearts. Who were we to hide in the safety of our comfort zones while hundreds of young people risked arrest for all of us?

In that moment, it dawned on us that as science seeks truth, activism speaks truth to power.

Several hundred demonstrators tie themselves to the fence outside the White House to protest the Keystone XL Pipeline. Image: Susan Walsh/AP/REX/Shutterstock

Of course nothing, including activism, comes with guaranteed outcomes, but it at least provides a tried-and-tested strategy for shifting the status quo and fostering social change. Years of grassroots resistance led the Obama administration to reject the Keystone XL pipeline (progress Donald Trump is trying to undo). And we've seen firsthand how fossil fuel divestment has helped to reframe the climate narrative from a technocratic problem about greenhouse gases to a moral one about fossil fuel production, climate denial, and social and intergenerational justice.

Then Donald Trump was elected, and our battles to stand up for science became a war. President Trump, EPA head Scott Pruitt, Secretary of State Rex Tillerson, and Chairman of the House Science Committee Lamar Smith are just some of the many politicians abusing their positions of power to advance their ideological agendas. Their attacks on climate science are an affront to all the scientists working to understand and solve this singular crisis of our time. What's more, people's lives are at stake. "The War on Science is more than a skirmish over funding, censorship, and 'alternative facts,'" says scientist Jon Foley. "It's a battle for the future, basic decency, and the people we love."

March and mobilize

Now, more than ever, we need to demonstrate that the majority of the public understands the realities of climate science and demands clean air, clean water, and clean energy. That we won’t allow our democracy to be hijacked by Big Oil and billionaire ideologues. We've already seen how concerted opposition by activists, lawyers, and journalists can stop the Trump administration in its tracks on immigration and health care. We are not powerless to change the course of history.

When we attended our second climate march on Sep. 21, 2014, it turned out to be the biggest the world has ever seen. We volunteered as Security Marshals and had the privilege of leading 310,000 people through the streets of New York City, calling on world leaders to take bold climate action. We’ll always treasure that day, but most of all, the hours spent at the finish line, watching miles of people-power flow by. People who shared our hopes, our fears, and our resolve to do something about the climate crisis. People who cared enough to show up.

On April 29, we'll march again — this time through the streets of D.C. — in the People's Climate March. We'll march to oppose the Trump administration's reckless anti-climate agenda, to defend climate science and democracy, and to stand up for social justice.

And we'll channel that momentum into sustained and collective action. From students pushing their universities to divest from fossil fuels and mothers demanding statewide access to clean energy, to business owners building a circular economy for the fashion industry and scientists combating fake news, we all belong to social pillars that can either support the status quo, or challenge it. We can all be storytellers, innovators, fixers, or changemakers.

We hope you'll join us on April 29, and in the months and years ahead, for as long as it takes to build a decarbonized, just, and sustainable world.

Ploy Achakulwisut is a Ph.D. candidate in Atmospheric Science in the Department of Earth & Planetary Sciences at Harvard University.

Dr. Geoffrey Supran is a postdoctoral researcher in the Institute for Data, Systems, and Society at the Massachusetts Institute of Technology and in the Department of History of Science at Harvard University. He has a Ph.D. in Materials Science & Engineering from MIT.