It’s about to get very cold in the Midwest. Here’s what the president of the United States tweeted in response to this news:

In the beautiful Midwest, windchill temperatures are reaching minus 60 degrees, the coldest ever recorded. In coming days, expected to get even colder. People can’t last outside even for minutes. What the hell is going on with Global Waming? Please come back fast, we need you! — Donald J. Trump (@realDonaldTrump) January 29, 2019

Where to begin. Let’s set aside the fact that wind chill is a meaningless way to assess cold weather; I don’t actually expect Trump to know that. We can also ignore the fact that he misspelled warming. The obvious thing to focus on is that he once again said something mind-numbingly incorrect about climate change. Except, we don’t have to focus on that, either, because Trump tweeted something similarly idiotic last week, too. (He managed to spell warming right that time.) That tweet kicked off a round of patient fact-checks explaining for the one-zillionth time that climate and weather are different, that cold weather will continue to happen even as the planet warms, and that, in fact, it might get even colder in some places sometimes thanks to climate change. As Trump himself said in last week’s tweet, it’s “amazing how big this system is.”

This news cycle has been happening on repeat at least since Sen. Jim Inhofe brought a snowball to the Senate floor, and we’ve been debunking it carefully each time. If you haven’t read enough explanations of the difference between weather and climate to understand why the cold doesn’t disprove climate change, I’d recommend Kendra Pierre-Louis’s version in the New York Times from last week.

The sad thing about this tweet isn’t even the deliberate misrepresentation of facts. That’s par for the course from the only world leader who doesn’t accept the science on climate change. It’s the tone of it that grates—the taunt inherent to “please come back fast, we need you!” In the midst of constant chaos and tragedy and stupidity, it is easy to forget that one of the greatest costs of the Trump presidency is the opportunity cost—the loss of these four years in which we could have been taking action on one of the most serious threats facing humanity and instead walked backward. This tweet is frustrating not only because it’s wrong—it’s frustrating because it is cruel. People are already dying from global warming. The longer we wait, the worse it will get. But to the president, it’s just a punchline.