This article is about 30 million years ago when the prior ice age was still cooling and had a long way to go before bottoming out. Thus, it was warmer then than it is now in our current ice age (Quaternary glaciation) that's just getting started back up ("only" since the past 3 million years).
Within that is another cycle: we're still in the Holocene Glacial period. Think of the below graph as expansion of the far right of the top graph. The Holocene Glacial (far right of the below graph) is a relatively short cooling phase, within the larger Quaternary glaciation that is warming.
And within that is the Modern Warm Period that we've been in since the 1800's.
Beneath the Antarctic ice: Gondwana’s lost world revealed by modern technology..
jpost.com/science/article-856909