Polar warming may be underestimated by climate models, ~50 million year old climate variability suggests

Polar regions are known to be warming at an enhanced rate compared to lower latitudes, with the Intergovernmental Panel on Climate Change citing a ~5 °C increase in air temperature over Arctic land masses during the 20th century and the highest rates of ~1 °C per decade since the 1980s. Clearly, this so-called "polar amplification" of warming, defined as the ratio of high-latitude (>60 ºN/S) to low-latitude (