Wednesday, August 08, 2007

We've crossed a threshold...

This is important, really important. In the summer of 2007 we have crossed some threshold, what others have called a tipping point. Something dramatic has occurred in the Arctic.

If you watch the following animation (credit to BostonGeologist at TOD) it shows the extent of melting for August 7, 2006 versus August 7, 2007. The melt rate has been increasing at a constant rate since 2000 when then last change occurred. But this change is even larger than the last change. There is a good chance that the old minimum ice extent may be broken by 25% or more before the melt season is done. The rate of ice melt has turned up sharply. This has implications for both the Arctic ice sheet and the Greenland ice mass as well. Further, this has implications for the thermohaline circulation.

What is now occurring may have crossed the line into the unstoppable. Dr. James Hansen's belief that we had 10 more years to stop global warming may be 10 years too wrong. And Hansen is derided as an extremist! People need to look around at what is occurring!

Very clearly we have crossed a threshold where the positive feedback forces are growing stronger at an exponential rate. The summer Arctic ice sheet may have less than five years left at this rate, maybe as little as three years. And the Greenland ice sheet just became a terrible unknown, whose melt rate has always exceeded prediction after prediction and now it may jump upward yet again.

There are two possibilities for the future here. The first, and most likely insofar as our limited understanding can discern, is runaway warming resulting in a much hotter planet, rapid desertification, loss of agricultural land, loss of fresh water supplies, and destruction of civilization. The less likely is just as bad with the climate being pushed into a warming event that ends the current warm period and thrusts us into another ice age. Both of these consequences can occur suddenly. Climate shifts have been recorded that happened in as little as five years and the typical climate shift is a few decades max.

And note that our civilization collectively refuses to do anything about climate change. We won't act until it is too late. I am now officially expecting something dramatic on the climate front this fall. I hope I am wrong but let's see what we get. It's almost too late now to prepare if you haven't been preparing already but you still have a tiny window. Remember, you were warned. Don't cry to me about your situation if your world suddenly changes for the worse.

8 comments:

Roccman said...

Holy crap!!!

godraz said...

This is just one of many dramatic ecologic tipping point signals converging that will soon add up to the following unforgiving message:

Nature does not make political compromises with anyone!

jjsonp said...

i don't necessarily disagree; however, i also don't think two year-over-year data points tell us much. i'd like to see that animation over the past 20 years or something; maybe this isn't unusual?

anyway it is quite interesting and i've been reading the thread on TOD so maybe the data are available.

godraz said...

jjsonp,

It's not only this dramatic decline of Artic sea ice that's at play here. The sub-arctic permafrost zone across all the northern countries is also dramatically thawing, and in the process of thawing is allowing formerly frozen in organic matter to warm up resulting in the release of untold amounts of CO2 and Methane. Ergo, all this leads to more atmospheric warming leading to more permafrost thawing and arctic sea ice melting, and so on.

The LATimes today published an artcile on this by Jeremy Rifkin.

Elizabeth Kolbert wrote about this too in her 2006 published book: Field Notes from a Catastrophe, and the news isn't good. One scientist she interviewed who studies this thawing permafrost phenomena said: "I think it is a time bomb, just waiting for the right conditions."

As far as the Arctic sea ice change goes, sure this could be a one year extreme, but the longer trend is clearly one of steadily more melting and less ice overall.

No matter how one slices this trend it is getting worse and worse each an every year. And eventually all these signal events (including the increasing drought and extremes in the Amazon, Australia, et al, and other extreme ecological stresses) are going to hit tipping points from which they don't bounce back to trend.

At that point the negative feedback loops are going to prove a real bitch with climate chaos as the new norm.

As Rifkin says: "A global tragedy of monumental proportions is unfolding at the top of the world, and the human race is all but oblivious to what's happening."

Better yet is this one: "[T]here is no otherness to the insanity that threatens us now. The insanity is what we call normal, and it is all our own." -- Verlyn Klinkenborg, NYTimes 4.11.07

fallout11 said...

The Arctic sea ice has been in decline since the 1950's [Vinnikov, et. al. 1999]. This decline is most pronounced in the summer [Stroeve, et. al. 2005].

Here you can find a 20+ year animation sequence for Arctic ice coverage leading up to Greyzone's animation sequence (1979-2005):
http://www.nasa.gov/centers/goddard/news/topstory/2005/arcticice_decline.html

Satellites have made continual observations of Arctic sea ice extent since 1978, recording a general decline throughout that period. Since 2002, satellite records have revealed unusually early onsets of springtime melting in the areas north of Alaska and Siberia. In addition, the 2004-2005 winter season showed a smaller recovery of sea ice extent than any previous winter in the satellite record, and the earliest onset of melt throughout the Arctic.

With the exception of May 2005, every month since December 2004 has seen the lowest monthly average since the satellite record began. Although sea ice records prior to late 1978 are comparatively sparse, they imply that the recent decline exceeds previous sea ice lows. Current levels of Arctic sea ice are likely the lowest they have been for the past few centuries.

I'll add that it's not just a northern hemisphere problem.....The Antarctic ice pack is degrading badly, and even at the present rates the Andes are expected to be entirely glacier-free within the 10 years.

fallout11 said...

Sorry, Nasa link again:
http://www.nasa.gov/centers/goddard/news/
topstory/2005/arcticice_decline.html

Greyzone said...

jjsonp:

I posted this precisely because it is such a weird anomaly. Go back and review the increasing melt rate year by year from, oh, say 1990 forward. There is one rate to about 2000, then a step higher, then this year which is another step higher. And that change is in the rate of increase. So it was increasing all that time regardless but at each of those step points seemed to worsen noticeably.

sjn said...

I've been trying to raise awareness of this for months, it's good that it's beginning to be noticed.

I've been following "Cryosphere Today" for a few years now, and this year really stood out. Something else that stood out to me was the freeze last winter; it appeared almost top-out at 9 million sq km before flipping back on course. Something to look out for...