We who live in the Northern Hemisphere (and that's most of us) don't think much about the Southern Hemisphere until we point out some incongruences like how Australians carve watermelons for Halloween.
The truth is that the earth's Southern Hemisphere is really different from the Northern Hemisphere. In the north, we have a lot more land, but the pole has none, while the south has more sea but the pole is covered with a land mass. That, and other factors, make a distinct difference in the atmosphere, the pollutants, and the weather of the two hemispheres. There's even a sort of barrier around the middle where the earth spins the fastest that keeps the two halves of the earth distinct from each other. Hank Green explains the geological, astronomical, and cultural factors that make the Southern Hemisphere cooler, stormier, and cleaner.