Summer temperatures in the Arctic have climbed 2.2°F since 1900 despite an 8,000-year cooling trend, the Guardian reports. For the past few thousand years, the orbit of the Earth and the changing tilt of its axis has put the Arctic 630,000 miles further from the sun than in the year 0, which would have left the region 2.5°F cooler than it is today without human intervention, scientists say. They blame greenhouse gases for the cranked-up heat.
“The accumulation of greenhouse gases is interrupting the natural cycle towards overall cooling,” says the lead author of a new study. “There's no doubt it will lead to melting glacier ice, which will impact on coastal regions around the world. Warming in the region will also cause more permafrost thawing, which will release methane gas into the atmosphere,” causing further warming. The researchers made a record of 2,000 years of Arctic temperatures by analyzing ice cores and tree rings.