In the year 3000 BC there was a recorded worldwide event that damaged the ozone layer, significantly reducing it to 1/7th it’s size. Because of this nothing lives as long or can grow as tall. Making the atmosphere thicker would probably be on their list of things to do. Giantism has been proven to accelerate under the proper atmospheric climate, just like plants grow bigger and better under certain conditions.

all i can think is, Barron went bsck to that time and that is why he is so darn tall