The complexities of the sun
The distance of where you are from the Sun is constantly changing because the Earth's orbit around the Sun is VERY irregular. Start by learning the three Milankovitch Cycles, then look into Solar Inertial Motion. None of this has anything to do with humans. None of this has anything to do with CO2. The models of the Solar System you grew up believing as a child were gross over simplifications. They conditioned you to believe that the Solar system has regular orbits, of which the Earth is one. Yet that is not the reality: not only the earth both tilts and wobbles as it orbits, but the orbit is an ellipse not a sphere, meaning the distance from the Sun is not constant. These are the three Milankovitch cycles. Then the combined mass of the planets also changes the centre of the Orbit, meaning the Sun appears to move rather than being in the fixed centre of the Solar System. This is called Solar Inertial Motion. And this is just the beginning of the story of irregularity in the Earth's orbit around the Sun, then there are cycles of Sun activity, making it stronger and weaker according to how many Solar Flares we are exposed to.