Rapid Retreat of Arctic Ice Warms Land and Melts Permafrost

The swift retreat of Arctic sea ice could more than triple the rate of warming far inland across Alaska, Canada, and Russia, leading to accelerated melting of permafrost, according to a joint study by the National Center for Atmospheric Research and the National Snow and Ice Data Center. The study showed that after last summer’s record low sea ice in the Arctic — when ice extent was 30 percent below average — temperatures on surrounding continents rose more than 4 degrees F. In a paper to be published in the journal Geophysical Research Letters, a team of researchers discovered that during periods of rapid sea ice loss, the rate of Arctic land warming is 3.5 times greater than the average 21st-century warming rates predicted in climate models. Scientists now say Arctic sea ice is warming so quickly that the Northwest Passage could be ice-free and navigable in summer within 10 years. The researchers used models showing that in periods of swift ice retreat, the permafrost in Alaska, Canada, and Russia could melt extensively, releasing large amounts of carbon dioxide and methane, a potent greenhouse gas. Experts say Arctic soils hold more than 30 percent of carbon stored in soils worldwide.