Wednesday, March 30, 2016

This Year's Arctic Sea Ice Maximum

So this year's Arctic sea ice extent was a record low of 14.58 Mkm2, just 0.1% below the previous record, which was last year at 14.60 Mkm2. (NSIDC data: long-termrecent.)

Obviously 0.1% doesn't matter per se. But what does matter is the long-term trend, and both this year and last year were below it. And there's no rational reason to think that melthing has stopped here, as this kind of antiscientific idiocy would have you believe.

Just as early 2016 surface temperatures blew away those of 1997-98, so too will Arctic SIE someday blow away the summer minimum of 2012. No one who knows the science wouldn't take that bet.

I had kinda thought that deniers would have been so embarrassed by this month's extreme surface temperatures, after years of writing about the "pause" -- which showed their acceptance of NOAA, GISS and HadCRUT data, but only after several prior years in the early 2000s of denying those data could be right -- that these kind of shenanigans would have been abandoned.

But apparently dishonestly has no limits at all. Soon, I expect, deniers will be blaming us for not communicating clearly to them just how serious climate change could be.

(I'm not joking.)


Lars Karlsson said...

Well, that Bob Tisdale piece wasn't so bad. He actually shows a graph (figure 3) where one can see that current temperatures are about 0.3 C higher than during 97/98. He just fails to draw the obvious conclusion, but let's not ask for too much.

David Appell said...

Lars: +1

David in Cal said...

The declining sea ice extent at the North Pole is important. However, to avoid cherry-picking I think one should look at both poles. The long-term expansion of South Pole sea ice extent suggests that two factors may be at play: long term global warming and also some sort of global shift in wind or water currents.


JDBishop5 said...

David - 'The long-term expansion of South Pole sea ice extent suggests that two factors may be at play'

No, it doesn't. It means that the Antarctic Continental Ice Mass is melting and the resulting fresh water, which freezes at a higher temperature, is floating on the sea surface and freezing trapping heat below the surface that erodes the base of important Antarctic glaciers threatening the world with an unexpectedly rapid oceanic level rise.

OnymousGuy said...

David in Cal said "However, to avoid cherry-picking I think one should look at both poles."

The two poles are not equivalent. One is a land mass, the other an ocean. The dynamics are entirely different.

What they have in common is the intrusion of warming waters.

David in Cal said...

JDBishop5 and Onymous -- you both make good points. Still your points would be stronger if they'd been made before the Antarctic ice expansion. Correctly predicting the future is harder than rationalizing something that has already happened. However, the models called for shrinkage of ice extent at both poles.

A thought experiment: Suppose Arctic ice had expanding and Antarctic ice had been shrinking. Would climatologists still focus more on Arctic ice than on Antarctic ice?

Layzej said...


Fresh water may play a part, but: "A basic problem, though, is that the greatest discharge of meltwater is occurring in the Amundsen Sea, exactly where sea ice is declining, so while this probably is part of the story, I doubt it’s very dominant."

DiC: This app lets you compare NH to SH sea ice evolution:

Use the slider or arrow keys to change the month.

David in Cal said...

Thanks, Layzej

Brian said...

I've always like the quote from the Last King of Scotland, "But you did not persuade me":