Compared to the large ozone hole that forms over Antarctica each year, Arctic ozone loss has generally been much more limited. But in 2011, Arctic ozone declined to surprisingly low levels. What did climate have to do with it?
In the mid-1980s, the winter sea ice pack in the Arctic was dominated by multi-year ice—ice that had survived at least one summer melt. Today, less than half of the sea ice at winter maximum has survived at least one summer.
The low ice extent recorded this September continued the downward trend seen over the last 30 years. Meanwhile, scientists are finding that the ice cover has grown thinner, making it more vulnerable to melting during the summer.
At the highest point atop the Greenland Ice Sheet, Matthew Shupe and his colleagues are installing a suite of climate and weather instruments. Their goal is to better understand the role of clouds in the rapid warming observed across the Arctic region.
Minimum sea ice extent observed by satellites each September has decreased by 13 percent per decade since the late 1970s. All six of the smallest September minimum ice extents have occurred in the last six years.
On September 27, 2013, Working Group I of the Intergovernmental Panel on Climate Change (IPCC) presented its report to member governments for approval and acceptance. The report is the first of four that will make up the IPCC's 5th Assessment.