The current rounder orbit yields less variation in solar radiation as the Earth moves around the Sun; the Northern Hemisphere is closer to the Sun during winter.
Larger tilt results in greater extremes between seasons - hotter summers and colder winters.
Our current tilt toward the North Star points the Northern Hemisphere toward the Sun during calendar summer to receive greater solar radiation.
These alterations of solar radiation affect climate on Earth over geologic time, triggering periods of cold glaciation and warm interglacial times.
The current global warming is not part of any of these cycles.