Even with historic heat waves simmering here and around the world, it's important to acknowledge that a few sweltering days do not a global climate crisis make. To ascribe every hot day to human-caused global warming would be as presumptuous and counter-scientific as the arguments of climate-change deniers who point to the occasional cold snap to claim it's all a hoax.

But as St. Louisans sweat it out during the coming string of predicted 100-degree-ish days, they should remember that there is evidence — reams of it — indicating that heat waves like this one are becoming more broadly common worldwide. That's based not on today's weather or tomorrow's, but on decades of real-world data showing beyond any rational doubt that this crisis is real.

It's also confirmed by hundreds of centuries' worth of ice-core samples, fossils, tree rings and other evidence that has helped scientists chart the climate's path through the ages. From this, they know that carbon dioxide (a key greenhouse gas that traps the sun's heat in the atmosphere, preventing it from naturally wafting back out to space) stayed at relatively consistent levels, never exceeding 300 parts per million, for more than 800,000 years.

After all those millennia, CO2 levels spiked past 300 ppm in the 20th century for the first time, as global industrialization and widespread burning of fossil fuels spewed unprecedented amounts of it into the atmosphere. Then it passed 400 ppm in 2014.

That cause and effect is undeniable, as are the average global temperature spikes that followed. The 10 hottest years on record (as a global average) have all occurred within the two decades of this century, according to the National Oceanic and Atmospheric Administration. Early July saw some of the hottest individual days, globally, in all of recorded human history.

You don't have to be a scientist to know the rest. You just have to watch the news.

Arctic ice is melting at never-before-seen rates. Sea levels are rising. Annual storm patterns, primed by hotter, wetter air, have become stronger and less predictable. Drought, wildfires, floods and other natural phenomena have taken on unnatural cycles and severity.

The current global heat wave is decimating records (and likely will again in the coming days) throughout the Americas, Europe and Asia. An analysis released this week by an international group of scientists declared it "virtually impossible" that the current heat waves would have occurred as they have without human-caused climate change.

In essence, the things scientists have been predicting since the late 20th century (often to the jeers of industry defenders who accused them of alarmism) are now upon us — generally more quickly and powerfully than predicted.

It's not like there's any mystery here. Science knows what is causing all this. Almost no one outside the steadily shrinking echo chamber of right-wing climate-change denial still clings to the delusion that it's anything more or less than human activity.

We also know how to combat it. But breaking our addiction to fossil fuels has proven so far to be a political impossibility both domestically and globally.

Whether the specific temperatures at a specific location like St. Louis would have gone as high as they're going on these specific days, absent human-caused climate change, is unknowable and ultimately irrelevant.

But the undeniable fact is that Earth as a whole, on average, is getting warmer. Within those averages, more days like this are in store for St. Louis and elsewhere. It's a mathematical inevitability — at least until cooler heads prevail.

REPRINTED FROM THE ST. LOUIS POST-DISPATCH

Photo credit: Pawel Janiak at Unsplash