A few years ago, Naomi Klein wrote a book called “This Changes Everything.” Klein is a climate activist, Canadian-born. Either we make sweeping changes in how we live on the planet now, she wrote, or we accept our fate.

Our fate is both tragic and terribly ironic. As we enter the Anthropocene Age, we ought to be celebrating the triumph of human ingenuity that the science-community-approved moniker represents.

After millennia of cowering in caves, watching loved ones snatched away by illness, and planting seeds only to see the crops shrivel under clouds of locusts, we’ve finally tamed the evil forces of nature. We’ve ascended, innovation by innovation, to the top of the food chain. We are at last fully in charge of our destiny and that of all living things.

And yet … never in human history have God’s creatures, humans included, been so imperiled. Described more than a century ago, the greenhouse effect was identified as an imminent threat back in the 1960s by Rachel Carson, among others. As a magazine editor decades ago, I assigned a cover story on doomsday scenarios, which seemed to be unaccountably multiplying. With tongue in cheek, the writer summarized the top 10 threats (depleting ozone layers, tainted food, the greenhouse effect and so on) so as to arm readers with an intelligent quip or two should one of these dire “menaces” come up at a dinner party.

Why the lighthearted tone? America was in a lighthearted mood, drunk with pride over having defeated the Red Menace. What were all these other menaces compared to that? If we could end communism, we could do anything.

But the implications of the greenhouse effect were not lost on the likes of Exxon Mobil. The oil and gas industry and all the other industries that benefited from its product, from autos to agriculture, conspired to create what I now think of as the politics of denial.

Studies were suppressed. Climate scientists were ignored or their predictions ridiculed. Some lost their jobs. Others found work in industries or academic institutions where they could do no harm. And as the effects of climate change became obvious to all, the new task became not how to fix this but how to “adapt.”

I follow a daily blog out of Washington, D.C., called FERN. It covers everything related to farm policy. Studies proving that certain pesticides are carcinogenic are posted alongside news of the ag lobby’s latest win on Capitol Hill.

A recent lead story was about dicamba, a tried-and-true weedkiller widely used in the South, especially in soybean fields. It was recently banned in Arkansas and Missouri, the home of the Monsanto Corp., which makes the seeds that are dicamba resistant.

Just as is happening with Roundup, crops genetically modified to be resistant to dicamba have encouraged farmers to spray more dicamba, not less. Whether dicamba itself is hazardous to human health (as the active ingredient in Roundup has been shown to be in study after study), no one knows. The immediate problem is drift; nonresistant crops are just as vulnerable to the spray as weeds are. The herbicide is spreading to non-GMO cotton and soybean fields owned by farmers who prefer not to grow genetically modified cotton and soybeans. Dicamba is killing their crops, destroying their livelihood.

Monsanto has sued the government of Arkansas. It says the jury is still out on dicamba. In other words, in American agriculture, a product is innocent until proven guilty. Which is the same as saying that a promising new cancer drug can be tested on humans until it kills a critical mass of them, and only then will it (maybe) be taken off the market. Monsanto insists, in its own words, that it’s “premature” to ban a product that holds out so much hope for humanity.

This has always been Monsanto’s argument: Trust us. We’re feeding the world. And usually it prevails. It may prevail still, in the South. Having merged with another giant global chemical conglomerate — Bayer AG, based in Germany — Monsanto is now one of the mightiest corporations in the world, and its pockets are deeper than those of, say, 350.org.

It also has new friends in Washington. The Trump administration will join the fight against farmers who still believe that freedom means freedom to grow crops on land they own in the way they believe they ought to be grown.

Buried toward the end of the FERN article on dicamba was the most alarming fact of all, with respect to climate. The real culprit isn’t dicamba, a pesticide that’s been around forever. It’s that weather patterns are so variable. Farmers just don’t know any longer when it’s safe to apply pesticide. Wind gusts seem to come out of nowhere these days. Crop scientists say they’re caused by unpredictable temperature inversions.

A University of Tennessee weed specialist named Larry Steckel explains why dicamba guidelines are difficult to satisfy: “You can’t spray when there is too much wind, and … if there is anything under 3 mph, you can’t spray it either. If you have a lot of acres to spray, that is hard to do. So, on paper, you can make this thing work, but in reality, if you are a typical farmer, it’s a major undertaking trying to get it to work.”

Temperature inversions are caused by atmospheric turbulence. “Our weather is simply out of control,” says William Mattson, a climate scientist who worked for the Forest Service in Michigan for decades. (He came to my house as a guest. I run an Airbnb. We got talking.)

He described a 10-year experiment he and his colleagues conducted in the Michigan forests in the late 1990s. They purchased carbon dioxide from a company that sold it to soft-drink manufacturers. These companies used it to carbonate their products. The scientists pumped the CO2 into the root systems of the trees in the forest, replicating the greenhouse effect. The trees thrived initially, as CO2 stimulated them to grow lush canopies. But in a matter of just a few years, the trees began to die. Their roots were unable to keep up with the growth of the leaves and branches. They could not pull up from the soil anywhere near sufficient nutrients to keep the canopies alive.

This is what we’re doing not just to nature but to our social infrastructure, by overstimulating consumers to grow an economy that is destroying our legal and political ecosystem just as surely as CO2 destroyed that patch of Michigan forest.

The forest has evolved because of the unique blend of inputs, as the ag industry likes to call fertilizers and the like. Too much fertilizer can be as damaging as too little because it throws the whole system off balance.

The biggest threat we face isn’t any one thing, Mattson told me. It’s everything.

Rear-guard action on a drought here and a flood there and fires all over the place is ultimately futile when the entire atmosphere is in tumult.

Corporations may have fancy gizmos to track the effects of weather, but they are at pains to predict it, and there is only one prediction that now is certain that didn’t used to be: The weather will be increasingly extreme and unforgiving.

We created this monster. There is no fix, quick or otherwise. This is the great challenge to our species — our own very survival — in the Anthropocene Age.

The writer, of St. Paul, specializes in environmental topics.