You are correct it will eventually cause some changes. But your point is obscured by the time-scale of the evidence you present to make it. By the time what you describe is responsible for making the earth’s temp hotter than humans can survive, the earth-bound humans will be long gone from the scene. They’ll either find a way to abandon ship or will have destroyed themselves in the mean time.
You couch your point in how the sun’s increased radiation, in galactic terms, will affect people in human terms. Your’s is a classic example of an oranges-compared-to-apples comparison. It short, it doesn’t make any sense.