One of the memes we are continually barraged with is the thought that if (or once) the Arctic becomes ice free, the decrease in the albedo will cause a significant feedback and hot up the earth even more than just the CO2/GHG effect. Scores of papers have tried to quantify the albedo effect and what it means to the earth’s temps. I once read, what I considered a fairly well written and fairly comprehensive paper attempt at such quantification. They even used some cool things I like to call “observations“.
Estimating the global radiative impact of the sea ice–albedo feedback in the Arctic by Stephen R. Hudson
The thing that strikes me, is that this illustrates quit well that we don’t know what we don’t know. Here is one of the graphics from the paper attempting to show the feedback……
Hudson concluded that the feedback was “if a complete removal of Arctic sea ice results in a forcing of about 0.7 W m−2, while a more realistic ice-free-summer scenario (no ice for one month, decreased ice at all other times of the year) results in a forcing of about 0.3 W m−2, similar to present-day anthropogenic forcing caused by halocarbons.”
Now, here we can see the most dramatic decrease in the arctic sea-ice is the most resent period. Yes, the dreaded death spiral…… I’ll put a graphic up that most readers may be more familiar with……
Ok, so with this dramatic loss of sea ice, going on for over a decade, we should see a response in our temps…. right?
I used the dynamic GISS data and then put the trends of the other temp tracking data sets and then offset them to show how they compared to each other. But, as we can see, it doesn’t matter which one we use, it has had no effect or it may be causing some cooling. So much for amplification.
We don’t know what we don’t know.
UPDATE: After I got done with this post, I poked my head up and saw that Anthony had posted Sea ice decline posited to be driving snowier NH winters
This is about a paper stating that less sea ice means snowier winters. Which could explain the zero response to the decrease in the arctic ice….. an albedo offset as it were. Now, we know NH winters have increased in snow cover, but that really doesn’t explain the no response. Winter is when we have the least sunlight to bounce back to the atmosphere. So, I wanted to see how our snow cover was in totality. I first did year around but, the graph showed nothing and was horrible to look at, so I removed May through August, because much of the NH wouldn’t have snow cover during that time anyway. So, here’s what I found…….
While there is a slight increase in the snow coverage, I don’t believe this would account for the lack of response to ice decrease.