Massive Flood That Caused Ancient 'Big Freeze' Located | Live Science
Younger Dryas was a cold time for earth, then the glaciers melted due to the earth warmed up, and there was no fossil fuel burning cars, utilities, humans driving the climate change.
The earth and the Sun also have this relationship where the earth precesses around it's axis, things are not static, so the earth positions itself differently to the sun over long time periods and that can drive Ice Ages, heating, cooling periods. The science claims 25,772 years for as single precession. I personally don't believe the earth is old, being a young earth creationist myself.
AST261Chap4,Preces.pdf (tcnj.edu)
Currently, the Earth’s axis precesses 360 degrees in 25,772 years and this length of time is called the precessional cycle or period. However, this motion does not change the 23.5o tilt of the Earth's axis, that is, the obliquity of the ecliptic. Actually, the precession is more complicated than what we have described here, since the Moon is moving in orbit around the Earth, thereby changing its position in space relative to the Sun. Hence the combined gravitational pull of the Moon and Sun keeps changing, thereby introducing other harmonics into the precession. For example, the Moon’s orbital motion around the Earth-Moon barycenter introduces a harmonic referred to as “nutation.” In addition, the orbit if the Moon is tilted 5 degrees from the plane of the Earth’s orbit. Planetary perturbations and the recession of the Moon caused by tidal effects are slowly lengthening the precessional cycle as well as altering the obliquity of the ecliptic.
