The list goes on. North Carolina has banned state planners from using climate data in their projections of future sea levels. So many Oregon parents have refused vaccination that the state is revising its school entry policies. And all of this is happening in a culture that is less engaged with science and technology as intellectual pursuits than at any point I can remember.

Thus, even as our day-to-day experiences have become dependent on technological progress, many of our leaders have abandoned the postwar bargain in favor of what the scientist Michael Mann calls the “scientization of politics.”

What do I tell my students? From one end of their educational trajectory to the other, our society told these kids science was important. How confusing is it for them now, when scientists receive death threats for simply doing honest research on our planet’s climate history?

Americans always expected their children to face a brighter economic future, and we scientists expected our students to inherit a world where science was embraced by an ever-larger fraction of the population. This never implied turning science into a religion or demanding slavish acceptance of this year’s hot research trends. We face many daunting challenges as a society, and they won’t all be solved with more science and math education. But what has been lost is an understanding that science’s open-ended, evidence-based processes — rather than just its results — are essential to meeting those challenges.

My professors’ generation could respond to silliness like creationism with head-scratching bemusement. My students cannot afford that luxury. Instead they must become fierce champions of science in the marketplace of ideas.

During my undergraduate studies I was shocked at the low opinion some of my professors had of the astronomer Carl Sagan. For me his efforts to popularize science were an inspiration, but for them such “outreach” was a diversion. That view makes no sense today.

The enthusiasm and generous spirit that Mr. Sagan used to advocate for science now must inspire all of us. There are science Twitter feeds and blogs to run, citywide science festivals and high school science fairs that need input. For the civic-minded nonscientists there are school board curriculum meetings and long-term climate response plans that cry out for the participation of informed citizens. And for every parent and grandparent there is the opportunity to make a few more trips to the science museum with your children.

Behind the giant particle accelerators and space observatories, science is a way of behaving in the world. It is, simply put, a tradition. And as we know from history’s darkest moments, even the most enlightened traditions can be broken and lost. Perhaps that is the most important lesson all lifelong students of science must learn now.