Maybe ten thousand years. That last ice age ending literally changed everything but yeah, ok, let's pretend its hundreds of millions of years the same.
Maybe, just maybe, if things are not behaving as expected, then maybe the cause isn't what theory says. Look at that list of countries. All contain deserts. All of whom I was taught experience these temperatures when I was in school in the eighties. I'm fucking old with a long memory.
Patience, mostly.