How does earth's orbit affect climate change?
The earth's orbit is relatively stable enough that it does NOT affect any of the changes observed in its climate.
Over geological time, it is more probable that slight changes in the inclination of the earth's axis and spin would cause changes in global climate zones. Periodic changes are also noticed with changes in the sun's energy output, often signified by the number of "sun spots" generated in a year.
A significant change in the earth's orbit would result in drastic changes to its climate, but the masses involved mean that it would require something like a planetary impact to nudge it.