[samadams2000]

My work confirms this.

[gr8eman]

Earth experiences periodic changes in its climate (which are related to changes in its orbit) has been understood for almost a century.

Uh...not by many! Any valid climate change argument (i.e. man-made global warming) should be backed up by empirical evidence. I am quite sure that natural forces, such as the gravity of the sun and changes in elliptical orbits of the moon and planets in our solar SYSTEM have way more effect on Earth's climate than air conditioning. Somehow I think the global warming crowd will ignore such findings!