Oops! I forget the link for my last post.
http://www.clearlight.com/~mhieb/WVFossils/Carboniferous_climate.html
I like you link! So basically, we are in an interglacial period which is in the middle of an ice age. THe reason has to do with continuous land mass going roughly from pole to pole and a large continent at one pole. So if we were to connect the Atlantic and Pacific oceans with a large, sea-sized channel, we could get out of this ice age and realy let the planet heat up. It's almost as if the El Nino / La Nina thermal oscillation in the Pacific really wants to ciculate the globe. Only that pesky Panama is in the way!