According to this AP article. And that’s a quote from the Old Testament. Googling “every man is stupid” and “old testament” finds a Bible hub quote, Jeremiah 51-17 as a source, which reads in the “English Standard Version”:
Every man is stupid and without knowledge; every goldsmith is put to shame by his idols, for his images are false, and there is no breath in them.
The pope was talking about climate change denial. And he seems to imply that deniers are “stupid”.
That is one theory. And a possible explanation for the basic contradiction that humanity was smart enough to develop civilization in the first place, and at the same is time stupid enough to burn all the fossil fuel.
Then again, if “every man is stupid” was true, how come humanity could develop the technology that enabled all that fossil fuel burning?
The alternative theory explained in “Great News” (my first global warming science fiction novel that I published five years ago) is:
We are not stupid enough to burn all the fossil fuel by ourselves. Rather, an evil alien is hypnotizing our leaders, deliberately causing a runaway global warming feedback spiral that will lead Earth to follow Venus.
As I said at the time, it is quite possible that some humans are stupid enough on their own.
But I still like my theory better, as well as the simple solution to the problem I found for my happy ending.