Question

would most likely change if the Earth's orbit around the sun becomes more rounded?

Answer 1

Not much. The seasons are actually the result of the tilt of the Earth's axis with respect to the plane of its orbit. If the orbit become more circular -- and it's awfuly near a circle as it is -- all that would happen is that the seasons in the North and South hemisphere would become more similar. As it is, since the Earth is farther from the Sun in the Northern summer, Northern summers tend to be cooler than Southern, and Northern winters milder than Southern winters. But these differences are swamped by regional variations caused by ocean and continent placement, winds and currents, et cetera, so I doubt they'd be noticeable.

Answer 2

Okay, Thanks :)