American science and politics always have had a complicated relationship.

Through the years, there has been friction between the two, and frequent misunderstandings. But now, with a new incumbent in the White House, and a new Congress sworn in, something fundamentally has changed. Scientists around the country are nervous as hell. And you should be, too.

Scientists are worried because there has been a sudden, seismic shift in Washington, D.C., and in its connection with facts and science. The relationship between science and politics has moved from mild friction to an all-out war.

The acceleration of the War on Science began in January with bizarre claims by the White House — clearly contradicting empirical facts — regarding the size of crowds, electoral victories, and voter fraud. Then Kellyanne Conway, an adviser to President Trump, suggested “alternative facts,” rather than actual truth, were in play. I don’t know what “alternative facts” are, but my parents called them falsehoods and lies.

A disturbing pattern has emerged in Washington: Facts and the pursuit of facts don’t matter.

Actually, it’s worse: Facts and science are being attacked because they matter a lot. And this attack is using a well-honed strategy.

First, the White House follows the “Merchants of Doubt” playbook to discredit well-established scientific findings. When you can’t win a debate with facts, it’s easier to cast doubt and interject confusion into the conversation, as was done to mislead the public about the dangers of tobacco smoke and acid rain. So it’s not surprising that President Trump and Environmental Protection Agency Administrator Scott Pruitt frequently use words to suggest that climate change might not be real, routinely saying “we’re not sure,” despite overwhelming scientific evidence to the contrary. The goal here isn’t to discover the truth, but to muddy the waters, and delay action as long as possible.

Then there are efforts to muzzle scientists. We have seen how multiple agencies, including the U.S. Department of Agriculture and the EPA, have ordered their scientists to stop speaking to the public. The Centers for Disease Control and Prevention canceled a long-planned conference on the health impacts of climate change. And when the Badlands National Park used its Twitter account to discuss the issue of climate change — as any nature center or park might do — the tweets immediately were deleted. Then the EPA suspended grants and contracts, and ordered the review of all scientific work by political appointees.

In late March, the U.S. Department of Energy directed staff to stop using the term “climate change.”

Now the Trump administration is using a sure-fire way to squelch inconvenient science: cut the resources it needs. The White House has proposed enormous funding cuts to federal science programs, especially those focusing on the environment, renewable energy and climate change — with wholesale elimination of crucial programs at the EPA, Department of Energy and National Oceanic and Atmospheric Administration. But the funding cuts didn’t stop there: The Trump administration also has proposed cuts to popular programs at the National Institutes of Health and the National Science Foundation.

It’s only been three months since Trump took office, but it’s clear that scientists are losing this war. And losing badly. We need help — the help of our fellow Americans.

Why should Americans care about science, especially when so many other issues compete for our time and attention?

Simply: Science is crucial to America.

Science powers the economy and creates millions of jobs. It creates medicines. It keeps us safe from toxins and disasters. And it fills us with a sense of awe and wonder — and hope for the future.

Our future depends on science. While science isn’t perfect, it can help lift us, improve the human condition and build a better world. And science serves all Americans, not just Democrats or just Republicans.

Let me be clear: This isn’t a partisan issue. Scientists aren’t — and shouldn’t be — worried about which political party is in power. It rarely has mattered: There is a long tradition of bipartisan support for science and a fact-based world view. Until now.

So how can we work together, as a unified country, to embrace science again, to solve the challenges of our time, and to thrive?

We need to share a bold, inclusive vision about the future to which all Americans can relate. Scientists won’t win friends by complaining about funding levels or the increasing pressure on scientists. Instead, we must show Americans how science advances our health, safety and prosperity, making us the leader of the world.

We need to channel John F. Kennedy: Don’t ask what Americans can do for science; ask instead what science can do for America.

And, in return, I hope our fellow citizens will stand up for science.

It’s time for all of us to show our support for science and for high-quality, independent research that serves our country and builds a better future. Whether we contact our elected representatives, attend the March for Science (whether in San Francisco, Washington, D.C., or hundreds of other cities across the nation) on April 22, or simply voice our support for science to our friends and neighbors, we need to speak out.

Most of the scientists I know have dedicated their lives to helping their fellow citizens — keeping us safe, protecting our planet, discovering wonders that power our economy, and pushing the frontiers of medicine. Now it’s time that we have their backs.

Jonathan Foley, an environmental scientist, is the executive director of the California Academy of Sciences. These views are his own, and do not reflect those of the academy or any other organization. Portions of this op-ed are adapted from pieces published in Scientific American and the-Macroscope.org. To comment, submit your letter to the editor at http://bit.ly/SFChronicleletters. Twitter: @GlobalEcoGuy