Very late response(sorry lol, just exploring old threads), but that figure isn’t often considered accurate, or at least only one of many possibilities.

Remember that the earth’s atmospheric pressure decreases over time, and it’s lost about half of its nitrogen density since it formed an atmosphere. Over billions of years it will lose its ability to trap heat, which will act as a counter to the sun’s heating. Also, a study done shows earth, in its current state, could very well get to 1.5 billion years much hotter but well short of a moist greenhouse state, the better of the two greenhouse states. Factoring in clouds and atmospheric pressure, models suggest that the greenhouse effect will be in a wide range from 650 million to 3.5 billion years. Also, the longer earth remains hospitable, the better it is for life, as it’ll enter into a moist greenhouse state instead of a runaway effect, where the planet is too hot for complex life, but shallow puddles combined storms and rain keeps some form of life until the sun dies.

Now, I’m a fairly spiritual person who believes in some life after death. This doesn’t affect any part of my being or consciousness. But I feel it’s worth mentioning that the relation between earth and a warming sun isn’t as doom and gloom as one would expect! I’ll link that study if you need it