Earth's precession, 23.5 degree tilt, and seasons question

Question

Is it possible that in 13,000 years it will be summer in December in the northern hemisphere? Or do we artificially change the definition of the length of the year to ensure this never happens?

Answer 1

Ever hear about a Leap Year?  That's is our way of adjusting the calendar to ensure that the year stays somewhat constant.  However, it is entirely possible for the magnetic poles to flip and possibly throw off our seasons.

Answer 2

Season are caused by the inclination of the earth. Months (the calendar) is defined by man.  that's why are months do not all have 28 days - like the Lunar Month.

We adjust our calendar to insure that everything "lines up" This is why we have Leap Years.  These make the adjustment.

Answer 3

It is possible, but Iowa still will not recognize leap year, so they will be way ahead.

Answer 4

The true period of the Earth's revolution about the Sun is the Sidereal Year, which is the mean time taken for the Sun to return to conjunction with a given star. Precession means that the Earth's equinoxes move with respect to the stars and the mean time for the Sun to return to the same equinox is the Tropical Year, which is the period to which the Gregorian Calendar is matched in order to keep the seasons occurring on the same dates. A Tropical Year is about 20 minutes less than a Sidereal Year.

If the calendar was matched to the Sidereal Year, then what you are saying is correct and the seasons would gradually migrate right through the year in a period of 26,000 years. But we match the Gregorian Year to the Tropical Year by introducing Leap Years, currently 97 in every 400. This should suffice for several thousand years, but some more tinkering will eventually be necessary, so you are correct to suppose that we artificially change the length of the year to keep in step with the seasons, but it 'is' done by means of Leap Years.