Lakefront property owners lose sleep over flood risks. High school students fill sandbags to protect the fragile coastline. America’s Great Lakes, the largest body of fresh water on Earth, are at, or near, historically high levels.

That scenario sounds all too familiar to local residents: last month Lake Michigan, the most variable of the Great Lakes, hit its highest levels since records began. But actually, I’m describing 1969, when I was one of the high-schoolers happy to be let off lessons to break my back on lugging sandbags, rather than my brain on trigonometry. There was ample angst then, too, about high water and the disappearing coastline. The difference was, no one blamed it on global warming way back then.

Today, climate change is everyone’s go-to explanation. When I walk my dogs on lakeside paths turned to ice rinks by the overflowing water, other dog owners mutter darkly about global warming. When Lake Michigan’s waves crash over Chicago’s famous lakefront hiking trails, the radio anchor fingers climate change. When Lake Superior floods my camper van site in the wilds of the state’s Upper Peninsula, a fellow camper assures me it’s because “Republicans don’t believe in global warming”.