By Matt Owens June 26, 2013
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The alarming loss of sea ice which has grown worse each summer over the past several decades, has taken a sharp turn for the worse: this year the loss is right in the middle, the most resilient part of the ice cover. This could lead to a completely ice-free Arctic Ocean by September.
Among scientists who study the Arctic sea ice, some think such an alarming total summer-time loss is likely within this decade, while others don't expect that loss for another 30 years or so.
The more open ocean there is in the summer, the more total heat the Earth absorbs each year, and notably: the more permafrost thaws. The open ocean absorbs lots of solar energy, and that is expected to pour out, especially in autumn, as heated water vapor. Most of this excess heat is expected to stay low, close to the ground, and form low cloud-cover over the Arctic Ocean and surrounding permafrost. This will insulate the region from losing its heat to the harsh sunless winter. This would be very bad because thawing permafrost will contribute huge amounts of greenhouse gas to the atmosphere. Aside from accelerating global warming and making our efforts to stop and/or counter it more expensive, the loss of sea ice could contribute to significant continued weather disruptions especially for the UK, but also around the world. The global climate is an interconnected system, and massive changes are underway. If you're not alarmed, you should be.
Below: Arctic sea ice concentration; from the US Navy here.