A New Look at the Arctic's Reaction to Climate Change

For years, people have viewed the Arctic as the canary in the coalmine of global change: As the planet gets warmer, the north feels the heat first, and feels it with the most punch.

This long-held notion may not be true, according to a few scientists who devote their professional lives to studying the climate of the Arctic. By gathering historic temperature and sea-ice records from the northern end of the globe, the group has found that warming in the Arctic during the last century is about the same as for the rest of the northern hemisphere.

Igor Polyakov is the leading author on the new study, soon to be published in the journal Geophysical Research Letters. Polyakov, a research associate professor at the University of Alaska Fairbanks' International Arctic Research Center, is from St. Petersburg, Russia. His connection with colleagues at the Arctic and Antarctic Research Institute in St. Petersburg allowed the researchers to gather detailed weather observations from Russia's Arctic. The records included decades of air temperatures from coastal outposts in Russia, and ice-extent reports from seas on top of the world: the Kara, Laptev, East Siberian and Chukchi.

The American and Russian authors of the study combined these records, some dating back to the late 1800s, with long-term temperature and sea-ice data from other dependable sources, including monthly air temperatures for Europe, Greenland, the Northwest Territories, and Alaska from the National Climatic Data Center in Ashville, North Carolina.

Armed with 125 years of weather records from the far north, the researchers compared temperature increases in the Arctic to those in the northern hemisphere and found that the two regions were warming at about the same rate. Scientists who in the past showed accelerated warming in the Arctic were correct, Polyakov said, but they primarily used temperature records that spanned only a few decades. The incorporation of temperatures from weather stations all over the north for 125 years gives a better picture of how climate change affects the Arctic, even if the image is not so clear.

"It's not simple," Polyakov said. "Judging climate by the recent 20 years may not give a suitable guess as to what will happen in the future."

Uma Bhatt, a co-author on the new paper and research assistant professor at the International Arctic Research Center, said many people assumed that global warming hit the north harder than more temperate latitudes, but not many challenged the idea.

"Everyone accepts polar amplification as gospel, but it's based on a partial picture," she said. "I believe in climate change, but something more complicated is happening."

Part of the climate confusion in the north is the fault of long-term weather patterns that make some periods cool, some hot. The 1990s were the warmest decade ever recorded in the northern hemisphere, but the 1960s were cool enough that some scientists wrote papers about an approaching ice age.

Polyakov and Mark Johnson, a researcher from UAF's Institute of Marine Science who is also a co-author on the recent paper, have found a tendency for northern temperatures to flip-flop every 35 years or so. They named the phenomenon the low-frequency oscillation. Driven by physical processes in the north Atlantic Ocean, the oscillations coincide with varying periods of atmospheric pressure. Low pressures over the Arctic, for example, cause more precipitation over land and less sea ice.

Scientists are now focusing more on the long-term patterns in the Arctic for a better view of the future, which is not quite as simple as a canary in a coal mine.

"Understanding the natural variability is important to understanding the change," Bhatt said. "It's more complicated than we thought."