DULUTH – Trekking down to the Duluth North Pier Lighthouse last weekend, all around me people were fanning themselves and grumbling about the humidity.

Duluth's "air conditioner" — Lake Superior — appeared to be out of order. And the lakefront brought no relief from the sticky heat.

It reminded me of a recent conversation with someone who was moaning about how it never used to be this hot. Nearly intolerable, they said. Hard to get cool. But the minute I mentioned climate change, it was like a switch flipped. Gee, the weather wasn't so bad. It was just a hot spell. It would pass. Hey, how about them Twins?

The phrase "climate change" seems to trigger a Pavlovian response in some people. Cue the eye rolls, the laugh emojis, the waving hands. It's not real. It's a hoax. The libs just want to scare everyone.

Climate change has become one of those topics that's so hard to talk about, like vaccines, Trump, and poverty. It shouldn't be. It's happening to all of us and it takes all of us to cope.

Last weekend, the temperature in Duluth hit 90. That's not unusual, even for a city that has been dubbed "climate-proof Duluth." Temps in the 90s date back to the 1800s, said Dean Melde, Duluth-based meteorologist with the National Weather Service. Last weekend, the wind was coming from the south and southwest, and no cooling breeze coming off the lake. That happens sometimes.

But something else was happening in Duluth during my visit. Perhaps more than the muggy evening, Duluthians who sleep with their windows open might have noticed that it never seemed to cool down that night. From 1 a.m. Saturday to 1 a.m. Sunday, the temperature never dropped below 72 degrees, according to Kenny Blumenfeld, climatologist with the Minnesota Department of Natural Resources.

"That's pretty high for Duluth," he said.

Ferociously hot weather claims attention, but we've gotta pay attention to what's happening to the bottom numbers, too. The winters that aren't as cold. Sultry summer nights.

"Maybe the high temperature isn't increasing that much, but the low temperature is increasing," Blumenfeld said. "So the ability to cool down during the summertime, we're kind of losing some of that."

The humidity is also a factor: what weather folks call the heat index. How hot it actually feels. The more humid it gets, the harder it is to cool off. Sweat stings our eyes, drenches our clothes.

Blumenfeld gives 50-70 talks a year throughout Minnesota. He's not political. He's not trying to change how anyone votes. He's a scientist, drowning in data, he half-jokes, and he speaks whenever groups invite him to their gatherings. In some groups, he refrains from using the phrase "climate change."

Farmers, who depend on his data to figure out what to plant and when, will nod along as he talks, having seen firsthand the weather changes that affect their crops.

"You know, oh yeah, longer growing seasons, I've seen that," he said, recalling what farmers tell him. "I've seen a drop in the frequency of really cold days in the winter. Doesn't seem like it gets as cold as it used to. Sometimes it rains harder and we end up with more water sitting in our fields."

Then they ask him if he believes in climate change. He explains that everything they've witnessed, and everything he was just talking about, that's what climate change looks like in Minnesota.

Blumenfeld thinks that to many people, "climate change" means something different from what they are experiencing. It means big scary changes like switching to electric vehicles or eating less meat. But farmers, especially, have front-row seats to how the Minnesota climate is changing.

It may be that Minnesotans resist talking about climate change or global warming because of the perception that they will be mocked.

But they might have more company than they realize.

In every Minnesota county, an estimated 60% of the population or more believes that global warming is happening, according to the 2023 Yale Climate Opinion Maps. Also in every county, at least 45% believes that global warming is partly caused by human activity. These estimates are based on large national survey data.

Whether you believe that the climate is changing, the attitudes of the people around you are. And, yes, once we accept that human activity contributes to climate change, then it makes sense to look at what those activities are and how to change them. Maybe that's scary, but it does need to be done. Because as Blumenfeld says, heat records have been blown away around the country, and that will happen here, too.

A muggy Duluth night is "nothing like what's coming," he said.