People forget the OCEANS in this discussion. 70.6 per cent of the oxygen that we breathe with each breath is produced by plants growing in the ocean. Also the carbon dioxide is dissolved into the ocean and ultimately may end up as sediments on the bottom of the ocean, which about 200 million years later will end up as limestone rock on a mountain somewhere on the Earth. They don’t know what they talk about.
Also the Sun is a main sequence star which will become a red super giant and expand and increase the radiation that it will produce. I’ll stop.