Below is a guest blog by Jos Hagelaars who regularly posts on Bart Verheggens Dutch-English climate blog. Jos has been a hot streak lately, looking back at how the Klotzbach 2009 Hot Spot paper is holding up, producing a new iconic graph called the Wheelchair (TM: Rabett inc.) and with his latest blog post discusses the result of the first Climate Dialogue that had Arctic sea ice as its first subject.
I wrote about this Dutch initiative when it was first presented, and even though I thought there wasn't enough talk about potential consequences/risks that disappearing Arctic sea ice poses, I found it actually exciting to have the representative of (fake) skeptics admit that the decrease is largely caused by Anthropogenic, or human-caused global warming. That ought to be a game changer. Some day. Hopefully soon.
Below is Jos Hagelaars' take on the discussion, starting with an excellent summary of everything regarding Arctic sea ice.
Melting of the Arctic sea iceby Jos Hagelaars
This was the title of a discussion that was held on the recently launched website ClimateDialogue regarding the possible causes of the decline in Arctic sea ice over the past decades. Three experts participated in this discussion: Walt Meier, Research Scientist at the NSIDC, Judith Curry, professor at Georgia Institute of Technology and Ron Lindsay, Senior Principal Physicist at the Polar Science Center of the University of Washington.
In this blog post I will start off with a description of the observations of the Arctic region, followed by a short overview of the potential causes of the decline in Arctic sea ice, incorporating the views of the three experts as they were expressed on ClimateDialogue. The final parts concern the uniqueness of this decline in a historical perspective and the possibility of having an ice-free Arctic in the summer in the not too distant future.Observations of the Arctic region since 1979
Since 1979 the Arctic region has been extensively monitored by satellites. They detect e.g. the ice surface area, the extent of the area covered with ice and also the total amount or volume of ice. The results of these observations are startling. For example, sea ice area and the amount of perennial (multi-year) ice has decreased dramatically over the past 3 decades, as is visualized by the images in figure 1 and 2, generated by NASA (see here and here).
Fig. 2. Perennial ice.
The bright white central mass shows the perennial sea ice. The larger light blue area shows the full extent of the winter sea ice including the average annual sea ice during the months of November, December and January.
Read the rest over at Our Changing Climate.