One of the most important measures of significant climate change is Arctic sea ice extent. Associated with the recent extreme/weird weather events during the last week of 2015, we had an intense low pressure system with hurricane force winds blow north over Iceland, and heating the North Pole surface air to above freezing. This happened, of course, during a time of year when the North Pole is normally in the middle of a 6-month stretch of cold darkness, spanning from the Fall Equinox to the Spring Equinox.
One consequence of this warm air blast is that Arctic sea ice extent flat-lined at 12.8 million square kilometers (of surface area with at least 15% ice coverage). To the right is a graph showing sea ice extent, with colored lines depicting the years from 2005-2016. This graph actually fuses two smaller graph fragments, both copied from NSIDC; on the left half is the graph for the last days of the year, and on the right is the graph for the first days of the year. The light gray background represents two standard deviations below the 1981-2010 average value (thick black line, near the top of the graph).
The right end of the flat red line marks January 4th. This is a record low sea ice extent, even below the previous record for 2011 (orange line). A significant concern with this low ice level is that, come Spring, there may be far less accumulated ice to melt, in both area extent and ice thickness. This may result in a rapid melt off, setting new low records through the Summer, beating the previous low records set in 2012. The minimal Arctic sea ice extent reliably occurs around September 15th each year.
A worthwhile discussion of the recent weather events was covered by a panel at the weekly show, HashtagVOA. Featured panelists included Robert Fanney (RobertScribbler blog), Dr. Jeff Masters (WeatherUnderground), and Dr. Steven Amstrup (Polar Bears International). Here’s an embed of the 30-minute video: