Rising global temperatures caused by humanity’s relentless appetite for carbon-based energy are not only changing life for humans, they appear to have reversed an Arctic cooling trend otherwise leading to the next ice age, a study published in the journal Science suggests.

The study, led by researchers at Northern Arizona University, examined temperature proxy records above 60 degrees North latitude, chronicled by decade for the past 2,000 years.

The researchers found that the Arctic was undergoing a pervasive cooling trend 2,000 years ago that continued through the Middle Ages and into the Little Ice Age. The trend was driven by the cyclical change in the orientation of the North Pole and the Sun, and resulted in warming of the Arctic by less than half a degree Fahrenheit per millennium, The New York Times reported in a story on the research.

But since 1900, the region has warmed by 2.2 degrees.

“The cooling trend was reversed during the 20th century, with four of the five warmest decades of our 2000-year-long reconstruction occurring between 1950 and 2000,” the researchers said.

In The New York Times article, lead researcher and author Darrell S. Kaufman said “The slow cooling trend [up until 1950] is trivial compared to the warming that’s been happening and that’s in the pipeline,” he said.