In an article on the NASA web site: What are the primary forcings of the Earth system? - NASA Science, the unattributed author states:
"According to scientists' models of Earth's orbit and orientation toward the Sun indicate that our world should be just beginning to enter a new period of cooling -- perhaps the next ice age."
This chart from NOAA (click to enlarge) shows temperature cycles during past glaciations. We're over on the right.
This chart by Tom Ruen illustrates global CO2 levels over the Pleistocene.
There's no causal relationship demonstrated by these graphs, just correlation. The important point is this pattern was active long before humans started producing greenhouse gases. This is a natural pattern of global climate change that humans cannot modify.
Don't get rid of your long johns just yet!