Stanford, Calif. — THE good news got pretty much drowned out this month: Yes, 2016 is on track to become the hottest year on record, but thankfully also the third year in a row to see relatively flat growth in global greenhouse gas emissions. With global economic growth on the order of 3 percent a year, we may well have turned a corner toward a sustainable climate economy.

The bad news, of course, is that the world’s wealthiest nation, home to many of the scholars scrambling to reverse global warming, has elected a new president with little or no interest in the topic. Or an active disinterest. Donald J. Trump is surrounding himself with advisers who are likely to do little to challenge his notion of climate change as a Chinese hoax. People like to think of us as living in an age of information, but a better descriptor might be “the age of ignorance.”

How did we get into this predicament? Why are we about to inaugurate the most anti-science administration in American history?

As a graduate student at Harvard in the 1970s and early 1980s, I was astonished to find how little concern there was for the beliefs of ordinary Americans. I was in the history of science department, where all the talk was of Einstein and Darwin and Newton, with the occasional glance at the “reception” of such ideas in the larger literate populace.

I had grown up in a small town in Texas, and later in Kansas City, where the people I knew often talked about nature and God’s glory and corruption and the good life. At Harvard, though, I was puzzled that my professors seemed to have little interest in people outside the vanguard, the kinds of people I had come from, many of whom were fundamentalist Christians, people of solid faith but often in desperate conditions. Why was there so little interest in what they thought or believed? That’s Point 1.

Point 2: Early in my career as a historian, I was further bothered by how little attention was given to science as an instrument of popular deception. We like to think of science as the opposite of ignorance, the light that washes away the darkness, but there’s much more to that story.

Here my Harvard years were more illuminating. I got into a crowd of appropriately radicalized students, and started to better understand the place of science in the arc of human history. I learned about how science has not always been the saving grace we like to imagine; science gives rise as easily to nuclear bombs and bioweapons as to penicillin and the iPad. I taught for several years in the biology department, where I learned that cigarette makers had been giving millions of dollars to Harvard and other elite institutions to curry favor.

I also started understanding how science could be used as an instrument of deception — and to create or perpetuate ignorance. That is important, because while scholars were ignoring what Karl Marx dismissively called “the idiocy of rural life” (Point 1), tobacco and soft drink and oil companies facing taxation and regulation were busily disseminating mythologies about their products, to keep potential regulators at bay (Point 2).

The denialist conspiracy of the cigarette industry was crucial in this context, since science was one of the instruments used by Big Tobacco to carry out its denial (and distraction) campaign. Cigarette makers had met at the Plaza Hotel in New York City on Dec. 14, 1953, to plan a strategy to rebut the evidence that cigarettes were causing cancer and other maladies. The strategy was pure genius: The claim would be that it had not been “proved” that cigarettes really cause disease, so there was room for honest doubt. Cigarette makers promised to finance research to get to the truth, while privately acknowledging (in a notorious Brown & Williamson document from 1969) that “Doubt is our product.”

For decades thereafter, cigarette makers poured hundreds of millions of dollars into basic biomedical research, exploring things like genetic and viral or occupational causes of cancer — anything but tobacco. Research financed by the industry led to over 7,000 publications in peer-reviewed medical literature and 10 Nobel Prizes. Including consulting relationships, my research shows that at least 25 Nobel laureates have taken money from the cigarette industry over the past half-century. (Full disclosure: I’ve testified against that industry in dozens of tobacco trials.)

Now we know that many other industries have learned from Big Tobacco’s playbook. Physicians hired by the National Football League have questioned the evidence that concussions can cause brain disease, and soda sellers have financed research to deny that sugar causes obesity. And climate deniers have conducted a kind of scavenger hunt for oddities that appear to challenge the overwhelming consensus of climate scientists.

This latter fact might be little more than a historical quirk, were it not for the fact that we’ll soon have a president whose understanding of science is more like that of the people in the towns where I grew up than those scholars who taught me about Darwin and Einstein at Harvard.

We now live in a world where ignorance of a very dangerous sort is being deliberately manufactured, to protect certain kinds of unfettered corporate enterprise. The global climate catastrophe gets short shrift, largely because powerful fossil fuel producers still have enormous political clout, following decades-long campaigns to sow doubt about whether anthropogenic emissions are really causing planetary warming. Trust in science suffers, but also trust in government. And that is not an accident. Climate deniers are not so much anti-science as anti-regulation and anti-government.

Jeff Nesbit, in his recent book, “Poison Tea: How Big Oil and Big Tobacco Invented the Tea Party and Captured the G.O.P.,” documents how Big Tobacco joined with Big Oil in the early 1990s to create anti-tax front groups. These AstroTurf organizations waged a concerted effort to defend the unencumbered sale of cigarettes and petro-products. The breathtaking idea was to protect tobacco and oil from regulation and taxes by starting a movement that would combat all regulation and all taxes.

Part of the strategy, according to Mr. Nesbit, who worked for a group involved in the effort and witnessed firsthand the beginning of this devil’s dance, was to sow doubt by corrupting expertise, while simultaneously capturing the high ground of open-mindedness and even caution itself, with the deceptive mantra: “We need more research.” Much of the climate denial now embraced by people like Mr. Trump was first expressed in the disinformation campaigns of Big Oil — campaigns modeled closely on Big Tobacco’s strategies.

We sometimes hear that those who ignore history are doomed to repeat it, but a “repeat” is perhaps now the least of our worries. Judging purely from his transition team, Mr. Trump’s administration could be more hostile to modern science — and especially earth and environmental sciences — than any we have ever had. Whole agencies could go on the chopping block or face deliberate evisceration. President Obama’s Clean Power Plan may be in jeopardy, along with funding for the Environmental Protection Agency and the National Oceanic and Atmospheric Administration. Grumblings can even be heard from Europe that if the Paris climate accord is abandoned, the United States may face carbon taxes on its export goods. Ignorance and its diabolic facilitator — the corruption of expertise — both have real-world costs that we ignore at our peril.