The March for Science in April 2017 was a unique demonstration of concern about the role of science and engineering in society and government. More than a million people in cities and towns around the world gathered in streets, made placards and banners, and heard speakers extoling the relevance and beauty of science—and also warning of diminished influence of science in policymaking. Some have dismissed the marchers as just another interest group advocating for more government funding for their work.

But the March, as I saw it and took part in it, represented something more: a significant change in how scientists see themselves and their work. This change had been slowly developing over recent decades and is now reaching a crescendo. Plans for another March for Science tomorrow indicate that the change among scientists is real, and that last year’s march was not simply a flash in the pan.

Scientists and friends of science are excited about recent progress in almost every scientific discipline. Whether it be observations of neutron star collisions, new findings on intergenerational epigenetic changes, macroscopic quantum entanglements, or human behavior, unprecedented scientific advances abound that will improve our future. Science marchers point to science as central to improving the human condition. At the same time, they are concerned about weakening public understanding and support of scientific research and the widespread neglect of scientific evidence. These concerns brought marchers to the streets in 2017 as much as pride in scientific accomplishments.

Signs, speeches, and chants at the 2017 March for Science demonstrated concerns about climate change, reduced environmental regulations, repeated failure of the government embrace and employ scientific findings, unpredictable research funding, and exclusion of scientist advisors from policy councils, among other issues. It was evident that marchers want more than recognition of great scientific advances and support for useful applications.

They want others in society—those who are not scientists, those who make public decisions—to recognize the power and effectiveness of evidence-based thinking. The marchers, most of whom have worked in science or related technical fields where collection, verification, and analysis of unbiased evidence is the principal goal, are frustrated by public decisions based on ideology or wishful thinking rather than verified evidence.

My experience at the American Association for the Advancement of Science (AAAS), the world’s largest general science membership organization, coincides with my observations about the March for Science. In addition to publishing journals of research, science news, and perspective and hosting programs of science in education, law, human rights, international affairs, and public policy, AAAS has for more than 150 years been an advocate for integrating good science into public life, society, and government.

In the past few years, we have engaged in more forceful and frequent advocacy, rephrasing our motto from “the voice for science” to “the force for science,” and after decades of slow decline in membership, our rolls have turned around dramatically. Our new members, who like our longtime members clearly value Science magazine, now say that they value even more our public advocacy and efforts to fully integrate science and engineering into society and government.

In short, we are seeing around the world—in marches, in scientific society membership, in civic participation—scientists joining with each other and turning outward. More and more scientists are leaving their cloistered labs and observatories, at least occasionally, and taking a constructive attitude toward seeking improvements in public health, environmental protection, education, and evidence-based policymaking.

What is the significance of the March for Science? It is scientists and friends of science saying they can, they should, and they will step into the public square. Previously that was unheard of. It is scientists in large numbers demonstrating to themselves and to others that engaging in public discussion is both appropriate and necessary. They are speaking up for science and evidence like never before.