Screw it, I'm just gonna ask: Why are the territories on Earth that are close to the South Pole really warm/hot, and the territories close to the North Pole are cold?

And just because this is The Dope, one will note that defining the tropics to this accuracy is not always meaningful. One thousandth of a degree of latitude is 111 meters.

The tropics are currently moving towards the Equator at about 46.8” per century, which is about 15 meters a year.

This is one of the Milankovitch cycles, and over the period of the cycle has a real influence on climate.

My father enjoyed showing people a picture of a sign on the road next to a line painted across the road denoting the Tropic of Capricorn, and pointing out that the real line was marching north at 4cm a day.

I just cut and pasted from an article on the tropics.