New paper finds long-term cooling of the Arctic over the past 4 million years & acceleration over past 1 million years

The Hockey Schtick
A new paper published in Earth and Planetary Science Letters finds from a geologic temperature proxy evidence that

"approximately four million years ago large climatic changes started to emerge that promoted increased glaciation of North America. Since one million years ago this effect has even been amplified in response to the drastic alternations between warm and cold phases of the ice ages."

From the geological definition of ice ages, the Earth is by definition still in an ice age due to the presence of ice caps at both poles. "