Arctic Sea Ice
EXPLAINED IN 82 SECONDS
WHAT IT IS
Since satellite observations began in the late 1970s, Arctic sea ice has declined precipitously. The annual minimum sea ice has been declining at a rate of 13.3 percent per decade since 1979. About 1 million square miles of ice have disappeared, or roughly a patch of ice four times the size of Texas. In 2012, Arctic sea ice reached its lowest extent in satellite record, and its seven lowest levels occurred in the past seven years. And extent isn’t the only thing changing: Arctic sea ice is getting younger and more brittle, making it easier for waves and warmer waters to break it up.
WHY IT'S IMPORTANT
Melting ice plays an important feedback role with global warming. Sea ice is much more reflective than the surrounding ocean, so its melting increases the amount of energy absorbed by the ocean. As rising temperatures reduce the area of sea ice, more solar energy is absorbed and temperatures rise even further. While an active area of research, new studies show that Arctic ice may also influence weather patterns around the world by creating cold air masses. Locally, declining sea ice is affecting the feeding and migration patterns of polar bears, whales, walrus and seals, and the people who live in the Arctic and rely on seasonal ice for their livelihoods.