[Kryptid]

I don't think changing how elliptical the orbit is would cause ice ages as we know them. The average temperature should be about the same.

[JLindgaard (OP)]

I don't think changing how elliptical the orbit is would cause ice ages as we know them. The average temperature should be about the same.

  And that is why ice ages occur. Average temperature should be but it isn't.

[Kryptid]

And that is why ice ages occur. Average temperature should be but it isn't.

After looking it up, it seems that you're right: https://www.sciencedaily.com/releases/2008/02/080213113037.htm#:~:text=These%20periods%20of%20more%2Delliptical,in%20the%20Earth's%20elliptical%20shape.%22

I originally assumed you were talking about an orbit with the same average orbital radius.

[alancalverd]

Put simply, in an elliptical orbit the planet spends longer at apogee then at perigee, so it cools down compared with its temperature in a circular orbit with the same mean kinetic energy.

[Bored chemist]

Since scientists do not know when the Moon started orbiting the Earth, could the Moon influence ice ages?

We have a pretty good idea when the moon stared orbiting the earth.
This is the current idea
https://en.wikipedia.org/wiki/Theia_(planet)
But even if that's not quite correct, we know when the moon formed because we can date moon rocks.

If you plan to criticise science, you ned to start by learning it.

Kind of why NASA's graph goes back about 800,000 years.

NASA's graph goes back as far as the ice cores go.
Did you not realise that?

Now, can you tell us what colour you think a sunset is?

[Kryptid]

Put simply, in an elliptical orbit the planet spends longer at apogee then at perigee, so it cools down compared with its temperature in a circular orbit with the same mean kinetic energy.

That makes sense now.

[JLindgaard (OP)]

 With moment of inertia, the Earth's spin would slow when glaciers in an ice age melt. I wonder if this causes the Earth to move faster through space. One reason why is the gravity assist that a planet's gravity can give a satellite.
https://en.wikipedia.org/wiki/Gravity_assist
 They often use a figure skater spinning with their arms out and in to show how that changes how quickly they spin as an example of conservation of angular momentum. With the Earth, it would require more force to rate it the same velocity as it could have during an ice age.