Polar ice cap

After seeing this incredibly depressing piece in the Independent,
Sea ice in the Arctic has failed to re-form for the second consecutive winter, raising fears that global warming may have tipped the polar regions in to irreversible climate change far sooner than predicted.

Satellite measurements of the area of the Arctic covered by sea ice show that for every month this winter, the ice failed to return even to its long-term average rate of decline. It is the second consecutive winter that the sea ice has not managed to re-form enough to compensate for the unprecedented melting seen during the past few summers.

I wanted to check out the data for myself (not trusting the spin of headline writers), and I found the absolutely incredible website The Cryosphere Today at the University of Illinois at Urbana-Champaign. They already made all the graphs I needed, and have animated GIFS of the icecaps to boot.
For example, this picture seems to address what the Independent is talking about, but I'm inclined to say that while the situation is clearly bad and getting worse, the Independent's spin is a little overdone.

Seasonal extent of Arctic sea ice, 1900-present. Source: Cryosphere Today.

You can see that the summer (green) line has been heading pretty steadily down since the middle of the last century. However, the trend in the winter (blue) line only started clearly down in the 1970s, and experienced a bit of a reprieve in the late 1990s (for reasons I don't know). It is really the apparent rapid end of that reprieve since 2000 that the Independent is highlighting.

You can also pretty clearly see why folks think the Arctic will be ice free in the summer by the end of the 21st century or so. If you go down from 12 to 8 from 1950 to 2000 in more-or-less a straight line, you'd hit zero in about 2100.

This obviously is behind the major warming of the Arctic - as the Independent puts it:

Scientists are now convinced that Arctic sea ice is showing signs of both a winter and a summer decline that could indicate a major acceleration in its long-term rate of disappearance. The greatest fear is that an environmental "positive feedback" has kicked in, where global warming melts ice which in itself causes the seas to warm still further as more sunlight is absorbed by a dark ocean rather than being reflected by white ice.
Well, this positive feedback would have been operating ever since the ice started shrinking around 1950. So far, it hasn't succeeded in bending the summer trend away from its rough straight line, so it's not clear there's really any evidence of some new threshold being crossed. It's also worth noticing that winter ice cover is almost completely irrelevant to the albedo feedback since the Arctic gets no sunshine in the winter. However, in high summer the Arctic gets nearly the same insolation as the tropics (the lower angle in the sky is largely offset by getting 24 hours of insolation instead of 12). So summer ice cover is extremely relevant to the Arctic heat budget.

All in all, I don't see any evidence here for the Independent's sudden crossing of some threshold of irreversibility. Rather, just the linear continuation of what is certainly a very worrying trend. Overall this can't be good for Greenland and sea level.

One thing that does seem a little more solid in the Independent's story is this:

Professor Peter Wadhams, of Cambridge University, who was the first Briton to monitor Arctic sea ice from nuclear submarines, said: "One of the big changes this winter is that a large area of the Barents Sea has remained ice-free for the first time. This is part of Europe's 'back yard'. Climate models did predict a retreat of sea ice in the Barents Sea but not for a few decades yet, so it is a sign that the changes that were predicted are indeed happening, but much faster than predicted."
Sure enough that does look like a pretty big anomaly:

Barents sea ice extent for last 365 days, together with anomaly from mean. Source: Cryosphere Today.

Perhaps there's hope after all for completing Prirazlomnoye sometime this decade?

Here's the situation across the Arctic right now:

Current Arctic sea ice conditions. Source: Cryosphere Today.

Sure does seem like as the thin ribbons of sea ice down either side of Greenland retreat, it can't possibly help the stability of the glacier ends.

I disagreee with you Stuart. I think the
situation is actually a lot worse than the
Independent article suggests. The discussion
has been centred around the area of sea ice,
but in fact the thickness of the ice is just
as crucial and there have been several reports
over the years indicating that the ice is very
much thinner than it was two or three decades

You say that positive feedback mechanisms have
been operating since the 1950s, but surely the
effect of the positive feedback is intensifying
almost annually. Sure there have been a few
years when the Arctic ice has grown on the
previous year's figure, but for the past three
years the loss of ice has been progressively
greater. Wasn't it around 8% last September?
In simple terms doesn't that equate to an
8% reduction in reflective area on 2004?

There is also the matter of the recently
reported sudden surge in CO2 level in the
Arctic region (as yet unexplained, but maybe
the result of release of CO2 from warmer ocean
of even tundra release.

I believe we are witnessing the effect of
synergistic mechanisms (Greenland ice sheets,
tundra emissions, warmer Arctic waters,
thinner sea ice -breaking up and drifting away,
lower sea ice area) all working together to
bring about a catastrophic meltdown of northern
regions within a couple of decades.

And pretty well every action by every citizen in
the industrialised world is adding to the
problem by way of out of control CO2 emissions.

And not one government on the planet is even
thinking seriously about the problem, (except
maybe a couple of Pacific islands) though the
Blair government makes a pretence of it by
talking about cutting emissions, whilst planning
additional airport runways for expected surges
in airline travel.

The disconnection between policy and reality
is nothing short of staggering.

synergistic mechanisms

or Complexity Theory

To summarize:

Like a sandpile, gradually adding grains of sand
will have little/no effect on the pile untl the Critical
Grain hits it causing an avalanche.

We're seeing the flickering of the Flourescent Tube
Light before it goes "critcial" or out.


You want something else of serious concern?

Winter in parts of Canada has been as much as 6 degrees above normal -- six degrees Celsius, that is, or about 11 degrees Fahrenheit.

Alberta, Saskatchewan and the Northwest Territories were more than 6 degrees above normal, the story says.

Just a jet stream aberration? At least in part due to global warming?

Or, a climatic tipping point from global warming?

or is the jet stream aberation a symptom of climate change?  to me "global warming" is (generally) a misnomer that allows the head-in-the-sand types to argue against human-impact climate change because, while some places get hotter,  others get cooler.  selective tree vision rather than the forest: the american way.   and there appears to be evidence of your "climatic tipping point from global warming" almost everywhere one looks.
oh, and we're running out of oil.
And another problem:

NASA says ozone is contributing to Arctic warming.

Globally, ozone accounts for perhaps one-seventh of the global warming and climate change that carbon dioxide does, Shindell said. However, a new study of climate change over the past 100 years indicates that ozone may be responsible for as much as 50 percent of the warming in the Arctic zone.

Question: While CFCs continue to be phased out, how much ground-level ozone from things such as automobile exhaust survives to be a factor in this cycle?

6.5 billion people can not be said to have no impact on any system no matter how big that system is.  Unless we are a Dyson Sphere, which we aren't.  Dyson sphere is a creature make construct completely enclosing a single Star, It is a work of Sci-fi  Though if there were one out there. only 6.5 billion people might not be able to influence it to much.

But on earth we are and have been able to influence our world no matter who you are we impact the rest of us in some way.

For thousands of years we never got beyond a few 100's of millions of people then bang!  We hit 1 billion, then 3, now 6.5 billion give or take a few 100 million who counts, who can guess the exact number.  We all make an impact, not just the guys who drive to work in a single car,  but the mom who burns the last tree within walking distance for the meal she fixes her kids.  

Reduce us all to burning trees and we become one big Easter Island,  Pretty fast too!!   There is nothing simple anymore, There is to many people here to make anything simple.  Even death is no longer simple,  Not that I wish anyone dead.  I am not painting a doom and gloom story, yet I know how some of you will take it.  We are living in a section of time that is both scary and exciting.  And can be happy too.


I thought that melting of the polar ice cap would not result in higher sea levels. The ice floates and thus takes the same amount of space as the melted ice (Archimedes). Am I wrong?
Removal of floating sea ice will not impact sea level but will change the albedo and result in greater warming.

There is the danger of futher positive amplification of this warming trend due to the release of GHG from the once frozen arctic tundra.

The Greenland ice cap is not floating. Scientific opinion is changing with regard to impacts. It was believed that increased warming would result in increased snowfall and sequestration of water in the Greenland ice cap. Current data shows continued abalation of the ice cap and glaciation retreat. This would contribute to significant sea level rise.

The ice above the water line is displacing its own weight in water. Consequently when it melts there will be no change in levels.

Likewise the albedo thing doesn't seem the major issue; the poles are very cloudy anyway.

I expect the real positive feedback is in the changing ratio of surface area to mass of the ice as it melts. Surface area decreases with the square, mass with the cube (pardon!), so the less ice, the faster it retreats. I suppose this is why we're seeing so much greater warming at the poles.

I suppose then the problem is the loss of heat sink. The phase change of melting ice soaks up a lot of heat. As the ice shrinks that sink goes away.

To dramatize this my old physics teacher would set a paper cup full of water on top of a bunsen burner. The cup sits there happily ignoring the blue flame underneath it right up to the point that the last of its contents is gone. Then it ignites.

So we may expect that more equatorial regions of the globe won't experience the full effect of warming until the polar ice is gone. At which point ... well, I'm too busy moving to Tasmania to think about it.

I'm from Tasmania, Why move there?  

I would it expect it to suffer severly from changes to the Antartic.

It is not just the Artic that is changing

What a fantastic find Stuart. Thank you. The animations are a stunning waste of time and I mean that in the most positive sense. I can look at the snow cover margin and remember "Hey, I shoveled that!" Need to do the same animation for the Hubbert Linearization graphics so we can all run them backwards and wistfully remember "Hey, I burned that!!"

Another data point: Canada is reporting its warmest winter in recorded history. One caveat - the historical record in this instance only goes back to 1948.

We've got a sense of humor here, but we don't joke. Know what I mean, fella? What does BOP stand for anyway? You got a liitle irked when jokerboy called ya Bop the other day. What were you irked about?
An OIL CEO who does not know what a BOP is ?  Curious.

Blow Out Preventer.  The assembly of valves which sits on top of an oil well to control the fluid / gas pressures.


I guess many contributors use TOD as a BOP :-).

Don't forget the melting tundra in Russia that equals an area the size of Germany and France combined. A huge quantity of methane is being released and, as we all know, methane as a greenhouse gas is ten times as effective as CO2.

Therein lies the positive feedback.

Sadly, rather than becoming alarmed, the world seems to think we need to figure out new technologies in order to continue our planet destroying ways.

But the planet will fight back, or rather, that is not quite right. The planet is more like an elephant infected with lice. It will simply roll over in annoyance and scrape the lice from its hide. The changing environment will take care of the pesky organism that is upsetting the balance of nature. The environment does not care. Humans? Schmumans.

We are like a frog sitting in the proverbial pan of water on a slowly increasing flame. Except we are a tech lovin' frog equipped with all manner of technology designed to increase the heat. And we KNOW this. Yet we do nothing. We will not started screaming and hopping until we are specifically harmed. Until we wake up with no food on the table, or the ocean encroaches onto our front step, or the plankton population collapses and suddenly, almost no fish remain in the ocean, we will keep thinking of new and better technologies, which can only exist with the petroleum base we have now, in order to keep the heat on.

I feel it is too late.

The permafrost feedback thing does sound really scary. However, methane concentration in the atmosphere has actually been stabilizing in the last decade, not going up faster and faster. I haven't been able to determine why this is from the scientific literature yet:

That's really hard to understand because methane emission is moslty Anthropogenic :
Anthropogenic sources (340 Tg/yr) predominate over natural sources (160 Tg/yr), and 80% of the total methane emission is of modern biogenic origin. Only 20% is due to fossil carbon sources (Wahlen et al. 1989)."

There are also natural methane sinks:

Woodland soils can act as effective sinks for both atmospheric methane, and for methane produced in deeper soil layers. The Intergovernmental Panel on Climate Change (IPCC) estimate that soils represent a methane sink of around 30 million tonnes per year. The methane is predominantly used by bacteria in the soil (methanotrophs) which use the methane as a source of carbon in a process called methane oxidation
src: www.ghgonline.org
There has been a big change in the way landfills are used in the US.  More stuff is filtered out before it gets there (a higher portion of yard wastes are now composted), and care is made to keep moisture content (and therefore decomposition) down ... I don't know if this is the key, but it might be over the same timeframe.
Landfills in the US now have to include landfill gas collection equipment per EPA requirement.  This is a network of wellpoints to collect the methane and CO2 generated and deliver it to central treatment equipment.  Older and abandoned landfills have to retrofitted.

That equipment is either a flare, to burn the methane, or a small, low BTU-capable engine/generator set.  Of course, some landfills like in LA can generate MWs of electricity.

Not a huge source of anthrogenic methane but not trivial either.

I suggest one possible explanantion:

The thinning ozone layer has increased the UV radiation reaching the lower layers of atmosphere. The UV rays cause the formation of more OH radicals in the atmosphere, which react with CH4 and oxidize it (via a chain of recations) to CO2 and H2O:

Photolysis of O3 to O(1D) in the troposphere is determined by a narrow band of radiation in the 290-330 nm range, reflecting the combined wavelength dependences of the actinic flux, O3 absorption cross-section, and O(1D) quantum yield ( Figure 1 ). Radiation in this wavelength range is strongly absorbed by overhead O3 and hence the production of O(1D) is strongly dependent on the thickness of the stratospheric O3 layer [Madronich and Granier, 1992].


The atomic oxygen O(1D) is the cause of formation of OH radicals in the atmosphere via the reaction:

H2O + O(1D) -> 2OH

Thus the more UV light reaches troposphere, the shorter the CH4 lifetime.

More seriously, here's a slide presentation on atmos. methane:


Stuart:  One reason may be, I haven't read it anywhere, it is only my silly opinion, all the easy to find NG has been depleted to such an extent that the natural NG seepage has slowed. It may in the future, cause the atmospheric PPM of methane to decrease, or until the tundra replaces the seepage. BTW do you have a web site for the charts on gh gases I had them once but lost them, except for CO2.
I heard a segment on NPR the other day about a discovery that plants may emit methane.  
Another point of view

Or maybe it all those cattle.

Gee, I thought it was the Boy's Own Paper.
Haven't you heard that laughter is the best medicine.
having been sick a lot in the recent months, not mention a second devorce and moving and etc etc.  Laughter is the best medcine for what Ails us.  Including the End of our worlds as we know them.  Lighten up, burn some propane and go hot air Balloning,  Its great fun and you get to see the world from a bit of a different view.
As the icepack gets thinner, the positive feedback is that it is easier for a breeze heading south to break it up and expose it to wave action to break it up more, or splash waves on it that melt it faster. So when it gets thinner, that is a very bad sign.
Unless you think global warming is a good thing because you live in Greenland or something.
This also affects the global conveyor belt and temperature excursions causing hurricaines in the Gulf and blizzards in Europe.
Seen this?


"the latest data shows CO2 levels now stand at 381 parts per million (ppm) - 100ppm above the pre-industrial average.

The research indicates that 2005 saw one of the largest increases on record - a rise of 2.6ppm.

The figures are seen as a benchmark for climate scientists around the globe.

The US National Oceanic and Atmospheric Administration (Noaa) has been analysing samples of air taken from all over the world, including America's Rocky Mountains. "

NASA says the cause is fossil fuels:

In the most recent press release, NASA did not directly tie the warming to humans and the burning of fossil fuels, which emits carbon dioxide, a key greenhouse gas.

But Zwally noted that the predicted climate warming cited in the press release is caused by manmade emissions. A natural warming cycle is technically possible, he said, but not likely given how closely the warming and models track.

Zwally said he expects to have even stronger satellite data within a year.

"We're seeing the early signs of changes in the ice sheets," he added. "The climate warming from greenhouse gases has really just started."

The ice has been thinning an incredible amount:

"The Navy has been recording ice data for decades, but like most Cold War calculations, the information has been top secret. If an unfriendly nation obtains information on where and when submarines had taken their measurements in the past, they might be able to guess where those subs would travel in the future.

But -- like the Arctic ice itself -- military secrecy seems to be thawing. About a year ago, Rothrock convinced Navy brass that measurements taken in the 1950s could be helpful in figuring out whether the data from the '90s was statistically significant. Armed with a pile of new numbers, Rothrock guessed that they might show that the polar cap had shrunk perhaps 18-20 inches over the past half century.

He was wrong. The actual shrinkage left him astonished.

On average, the University of Washington team found that ice had thinned by four feet (1.3 meters) -- a 40 percent decrease since 1953. The "trend" of the 1990s seemed to be an indisputable fact. "

from http://archives.cnn.com/2000/NATURE/01/03/arctic.ice/index.html

This is a link to the original paper:


So will we see the ice melt threshold only after we cross it -- kind of like seeing ye olde peake only after the fact?

Will the ice melt be a long bumpy plateau that is hard to evaluate, or will melt occur fast and clearly enough to convince skeptics that it is happening and is a big deal?

With our exceptionally big brains we humans ought to be able to gather and interpret the data and then create plans based upon those interpretations.

If only.....

I concur with pretty much all of the comments above.  The positive feedback loops are accelerating, and they all intertwine, so reinforce each other, which is why the term "faster than predicted" is showing up with such frequency in these reports.  Link TV showed Al Gore's GW slideshow this past weekend. It hits theaters May 26 - see it.  I follow all of this pretty closely, but I was chilled (NPI) at the holistic picture as he put all the data together, and actually gasped at one slide - CO2 levels now well above anything seen in over 400,000 years, and we're already committed to taking it much higher.  Everything is working together to crashmelt the arctic in much less than a century - put together what Ender says about the thinning with the Indy article on the receding, with the increased polar methane and CO2 and the shrinking albedo (which is significant) with the phase change and the heat sink and the fissures and meltpools that let the (increased?) winds do their thing and my money is on no summer ice before mid-century, perhaps much sooner.  The Larsen B shelf was supposed to last "100 years" and broke up in just over a month.  The arctic (and Greenland) are much bigger, but the same early signs are showing themselves.  Ramping up coal to replace depleting oil will be the proverbial final nails...
I agree with the other posters here who have homed in on thickness of the ice, not the geographic distribution.

It is much more important to focus on the thickness.  There is a lot of thermal mass in thick ice.  It takes an enormous amount of energy to melt it completely.  Therefore only limited reduction in geographic area is seen for awhile as the  environment heats up.  Most of the energy is going into reducing the thickness not shrinking the size.  Thin edges are easily recaptured the next cold period, but are meaningless.

Think of ponds or even large lakes coming out of the winter.  Many times the margins of the ice retreat from the shore even as there is thick ice out on the middle.  The edges refreeze intermittantly during cold nights in the spring giving the impression that there is no net loss of ice.  The reality is that the entire ice mass is undergoing net loss.  The same warm day later in the spring doesn't just shrink the margins again, at some point the whole geographic surface melts in essentially one day.  

Previous warm days, even very much warmer days, did not have the same effect because the ice mass was so much larger.  The data is clearly indicating this is happening in the high arctic.  Ice mass is diminishing rapidly even if the geographic area is shrinking at a slower rate.  At some point that geographic loss will increase significantly.  But it will only happen after the total mass has been reduced to a very thin layer.

Ok, I'm totally not a physics person but I remember how our High school science teacher showed how repeated heating and freezings of an icecube turned it from a cube to a thin layer of ice. Thus heat + gravity spread the ice out and then when it refroze it was Thinner & Wider. It would seem this is happening on a large scale at the poles. Thickness is being converted to cover more area as that is stripped away at the edges.

So yeah I agree that we should worry a lot more about thickness than coverage as a first sign of Global Warming.

I profess no expertise in either atmospheric science or geophyics, but it appears that one aspect of this whole global warming problem that is only starting to get much attention it the effects of  thawing out thousands and thousands of square miles of frozen tundra.

It is well known that there is a considerable exchange of gases between the atmosphere and the upper layers of the soil environment.  The exchange takes place in both directions - gases going into the soil and gases leaving the soil. Much of this exchange is the result of microbial activitity in the soil.

It's been postulated that a thawing of the tundra would essentially take the cover off of a very large area of soil and allow CO2, methane, and other gases formerly trapped in the soil to evolve into the atmosphere. I believe the main concern is with large amounts of methane hydrates turning into vapor and migrating into the atmosphere.  However, what I don't have any feel for is how extensively this mechanism has been studied and how well it is currently understood. Do we really know what's going on with this one?

Back to a question on polar ice melt:  If the polar ice cap recedes, that would expose more sea water to the atmosphere. And when that happens there is more surface area made available for an exchange of gases between the polar sea water and the atmosphere. Is it possible that this extra water surface could result in more CO2 being transported from the atmosphere to the ocean and thus improve its role as a sink for CO2?  If that is indeed the case, might that not serve as a negative feedback mechanism and serve to slightly retard the build-up of CO2?  Or is this just not significant?  

If the polar ice cap recedes, that would expose more sea water to the atmosphere

I would not rely that much on this effect. The sea covered by ice is some 3-4% of the global ocean, the best you can expect is that if all of it melts the global rate of CO2 absorbtion will rise by that percentage.

Um, CO2 is absorbed by cold water. The Arctic is cold. So CO2 absorbtion will go up a bit. But probably not enough to matter.
Now the CO2 absorbed by all the algae and seaweeds flourishing where all the ice used to be, that may be more significant.
On the heels of some of the other comments here about "synergies" and "positive feedback" loops, I'd like to provide this quote (see below) from the excellent and highly disturbing cover story in March/April 2006 issue of Mother Jones.  If we change the oceanic pH so fast that plankton cannot adept quickly enough, we've got a whole different mess on our hands well before sea level rise rears its ugly head.

In many ways, our addiction to combusting all forms of fossil fuels has been both a blessing for human technological advancement and a prime mover in a large majority of the social, economic, and environmental ills we face today.


"Among the most frightening news for coral reefs is the increasing acidity of the ocean as a result of rising levels of carbon dioxide. Scientists at the National Oceanic and Atmospheric Administration recently estimated the ocean has absorbed 118 billion metric tons of CO2 since the onset of the Industrial Revolution--about half of the total we've released into the atmosphere--with 20 to 25 million more tons being added daily. This mitigation of CO2 is good for our atmosphere but bad for our ocean, since it changes the pH. Studies indicate that the shells and skeletons possessed by everything from reef-building corals to mollusks to plankton begin to dissolve within 48 hours of exposure to the acidity expected in the ocean by 2050."

Another piece of bad news:

Study suggests climate models underestimate future warming

There was also an article in the Economist two weeks ago (Feb 23rd 2006).

There is a related discussion on the Google group alt.global-warming:

As reported in the February 25, 2006 issue of The Economist magazine,
in a recent meeting of the American Association for the Advancement of
Science, experts there (principally Karen Bice, researcher at the Woods
Hole Oceanograpic Inst) criticised the GCMs existing today for not
being able to predict paleo-climate based on historical CO2 levels that
existed then.

In layman's terms:  today's computer models cannot even get the past
right, so how can we expect them to predict the future?

The models were consistently biased towards underestimating
temperatures in paleo-climate, based on proxy data of ocean
temperatures provided, such as from oxygen-isotope ratios of fossilised
foraminifera.  In fact, the temperature of seas during the Cretaceous
period were 38C (!), nearly 100F, as opposed to the 28C found today.
Likewise the PETM (Palaeocene-Eocene Thermal Maximum) was much hotter
in fact than predicted by the models.

Re: "The models were consistently biased towards underestimating temperatures in paleo-climate, based on proxy data of ocean temperatures provided, such as from oxygen-isotope ratios of fossilised foraminifera. In fact, the temperature of seas during the Cretaceous...

It is not possible to model the ocean/atmosphere circulations and heat transport that far back in Geological time given the different configurations of the continents, only rough approximations of CO2 in the atmosphere, etc.

As for this Arctic result, it is not clear what the future trend may be. We may be witnessing the beginning of an abrupt climate change in the Arctic--that's the fear. The trend may remain linear for a while, however. It's only 2006. Paradoxically, I think we can be more certain about the longer term (2050 or after) than what will happen in the next 5 or 10 years assuming "business as usual" regarding GHG emissions. Still, there is no doubt that it possible that it may soon when the SHTF.

Meaning it's time to start engineering measures to offset the effects NOW; we won't be able to reduce GHG's for a while, but if we can restore the radiative balance we can stop things from tipping any further.
Control 6.5 billion people.  Not just the big controlable (sic) countries but the little guys burning tress for food making.  Just think what you are asking them to do.  Let alone  Not refinance the house again this year, with the all new 3.95% mortgages that the yahoo mail adverts claim I could have.
Hopeless much?

You don't have to control everyone with a grand plan.  But you can still PLAN (study, engineer, debate, cooperate), and if we aren't going to sink into some angry-melancholy, then that's what we are going to do.  There will be lots of plans, probably lots of attempts, and some might catch on as more workable than others, and there will be opportunities to get people onboard as the dangers become more clear.

When Pinatubo erupted in 1991, it controlled almost no one.  Despite this it dropped global temperatures as much as 0.6° C and sea levels fell by half a centimeter.

All of this was from a natural injection of aerosols.  If we did an engineered injection of aerosols...

About the positive feedback - on a longer time scale the beginning of a non-linear trend may look like a linear trend. That is you may fit the same data both to a straight line or to a bell curve in which the ice thickness falls down the cliff after some inflection point.

The positive feedback may not seem to have any effect in the previous half a century, but this is not a proof it will not kick in increasingly in the future.


The water that is now warmer as a result of less sea ice in the artic will take a long time to complete its journey through the thermohaline circulation. Wikipedia says some thousand odd years, so I certainly wouldn't expect to see mich non-linearity over a period of 50 years.

That said, if it only takes 100 years for the linear trend to hit zero, the non-linear effects may not have time to kick in.

reference: http://en.wikipedia.org/wiki/Thermohaline_circulation

You might want to read, or reread the 2/04 Fortune article on rapid climate change.  Yesterday, the Texas Panhandle had the worst grass fires in state history.  Eleven people died because of the fires.


The Pentagon's Weather Nightmare

The climate could change radically, and fast.
That would be the mother of all national security issues.
By David Stipp, FORTUNE Magazine, February 9, 2004


 Though triggered by warming, such change would probably cause cooling in the Northern Hemisphere, leading to longer, harsher winters in much of the U.S. and Europe. Worse, it would cause massive droughts, turning farmland to dust bowls and forests to ashes. Picture last fall's California wildfires as a regular thing. Or imagine similar disasters destabilizing nuclear powers such as Pakistan or Russia--it's easy to see why the Pentagon has become interested in abrupt climate change.

A Conversation with John Mutter in NY Times

Q. By your markers, was New Orleans a first world or a third world disaster?

A. After Katrina, I wondered about that. I started by looking at the death toll. In New Orleans, there are 1,417 bodies that have gone through the morgue and who've been determined to be Katrina victims. That doesn't count people who may have died in auto accidents escaping or those who died after they got to the point of escape. There are 4,000 people still unaccounted for. Some of them probably died. But whether it's 1,417 or 2,000, that's a third world number. Hurricanes that come through Florida take a dozen lives, maybe 20.

Q. Were there any discernible trends among the dead?

A. If you map their addresses, you find the flooded areas were often the poorest, with the highest number of African-Americans. This was a storm that selected for the poor, which is another third world marker.

Flood vulnerability is one of the classic things that poor people are subjected to. Anyone who's traveled can tell you why. It's because the slums are always around riverbanks, in drained swamps. The poor occupy the bottomlands. In this case, the Lower Ninth Ward or St. Bernard Parish or the areas near the Industrial Canal.

What's really different about Katrina is that this disaster selected for the old: of all the bodies that have been identified, 64 percent were over 60. And that plays against the fact that the population of the flooded areas, only 15 percent were over 60.

In floods, it's usually the very young and the aged who die because survival requires a great deal of physical stamina. Yet in New Orleans, there were almost no deaths among the young -- white or black. One under-5 black child died. In the under-40 population, no white people died. Among the aged, death became a kind of racial equalizer. It was old people, black and white, who ended up in St. Gabriel's morgue. In the flooded areas, if you were white and didn't escape, you were probably old.


Just to address a few comments. The Independent is claiming that we crossed a threshold were positive feedback is now cutting in and things are now irreversible where they weren't before. I just don't see that in the data. The summer ice extent looks like a straight line.

I'm not saying the positive albedo feedback doesn't operate, but rather that it's been operating all along, and is part of why the pole is clearly melting. There is no evidence in the data of some sudden cutin of positive feedback that wasn't there before. Now maybe the trend will change in the future, but I don't see any evidence in the data yet. I think the Independent piece is inaccurate.

Which is not to say that I think the North pole melting is a good thing. On the contrary the rapidity of the melting seems to me extremely alarming. While sea ice melting will have no impact on sea level directly, it seems that the implications for the stability of the Greenland ice sheet are quite alarming.

I took a look at the thickness data and I agree they suggest a somewhat faster course of melting - end-of-summer ice thickness hitting zero by mid-century rather than the end of century. However, the data quality is much poorer, and there is still no sign of a threshold, as opposed to a more or less linear trend.

Stuart, I came back here specifically to make this suggestion, and you've provided the perfect comment as lead in:  I'd love to see you do a line of best fit to that summer data to see where it leads.  I did it by eye, and it leads me to no summer ice in 2028.  If I hadn't nearly failed calculus, I'd do it myself.  My eye tells me that there's a flat line just under 11km2 through the early '50's, then a break down that seems linear to about 1990, then a period of oscillation (the fluorescent flickering as someone suggested) presaging another turn downward.  As I extrapolate, I see a break below 7km2 in 2010, below 6km2 by 2015, below 4km2 by 2020... last summer ice in 2027.  Wonder what best fit shows?  And if you take the thickness x the extent from the '50's to date to generate a volume reduction curve...  Well, we'll be able to get at that polar oil sooner than we thought - oh joy.
From the same website they give the following graph:

Values of NH sea ice area for the dates of annual historic sea ice minima

The slope is (5.5-6)/(1998-1983)=-0.0333 million km2/year, so the minimal surface extent could be 50% smaller than today in only 90 years.

'well, I'm too busy moving to Tasmania to think
about it.'

I guess you know that Australia is not melting
like the Arctic, but it is overheating and
drying out as never before. Tassie will
probably be the last inhabitable state of
Australia when climate change really
starts to bite. But London, New York etc.
will be largely under water by then.

I repeat my previous comment: the meltdown
of the environment is underway and all
[influential] governments are more or less
ignoring the issue altogether and are still
pushing ahead with policies that will ensure
the meltdown accelerates. If that is not
insane, then I don't know what is.

Even those nations that are making some kind
of effort to address CO2 emissions are
offering 'too little, too late' poliices
because they are still trapped by the ideology
of GDP and economic growth.

And along come China and India.

The coming decades are certain to be dominated
by attempted mass migrations by environmental
refugees, if not actual environmental wars.
Indeed, it seems to have started in East Africa.
And it seems there is absolutely nothing we can
do about it, except prepare for the worst.
The chickens are comiing home to roost. The
failed policies of the 70s, 80s and 90s (and
present) are resulting in their inevitable

Greenland will presumably become an increasingly
attractive destination. I believe the first crop
of potatoes in a thousand years was grown there
a couple of years ago.

Actually Australia as a continent has had one of its wettest summers on record. Almost constant cloud cover of the north west and center, monsoons reaching rain bands regularly across to the north and south east, and weekly cold fronts welling up from Antarctica to drench the south. About the only part that isn't sodden is Tasmania, which is in drought and forest-dieback.

But it has been hot.

Anyway Tasmania isn't the last stand of the Australians. We'll be settling Antarctica just as soon as the big thaw is done. That's a gigantic, virgin continent full of natural resources of all sorts.

But no trees.

Things are weird in Tassie too. I bought an inflatable boat but the summer has been so cold I've only taken it out once. OTOH a nearby ski tow area (altitude about 1300m) didn't operate at all last winter due to lack of snow. I'm hearing the opening bars of 'Exodus'.
Here in Perth, Western Australia we have had the coldest wettest summer in many years.  Last December was the coldest December since records began in 1890.  It has been really weird.

We in WA have a huge advantage of lots of land and only a few people.  Where else can you fly in a jet airliner for 3 hours and still be in the same state. (Perth to Broome)

Hmm. Seems like the same pattern in both hemispheres. A warmer pole fringed by a cooling region and then warmer but wetter again as you get to the tropics.

Perhaps the failure of thermohaline conveyance in both hemispheres could account for this.

If the gulf stream slows then there's less warm water circulating down to antarctica. Plus runoff from the melting ice there to increase the coolness; you expect southern Australia to get cooler and wetter.

Up to 60,000 years ago Australia had a vast internal lake system - the whole center of the continent was jungle and forest. Wombats the size of rhinos and carnivorous kangaroos like furry velociraptors. Then men and dogs turned up and that was that.

I wonder how long it will take for the kangaroos and wombats to re-evolve to their former dimensions? And I wonder what makes Tassie go dry?

It's kind of sad to see this article. I've read another article where ON THIS SAME site where it was explained that as long as all ice is melting at summer you can not get glacier but only even small amount of ice is unmelted by winter time glacier will grow, grow and grow.

It this is of course true. But here we have THE SAME situation - just in reverse...

WINTER icecup is CRITICAL for positeve feedback loop! Forget about albedo and insolation! While all ice melted in summer is fully replaced by winder feedback loop can not start. If some small part of ice melted in summer is not refrosen by winter it means next year there will be less ice. And the next wintnet ice cup will be even smaller. And so on. Like graciers just in reverse. Think about it...

In the midst of all the gloom and doom, we should at least consider the possibility that these climate changes will have good effects.

I'm going to go way out on a limb here and make a daring statement: the arctic is too cold! I know, I know, it's radical, it's crazy, no sane person could ever think such a thing.

But if we could manage to put ourselves into this wild, crazy frame of mind for a few moments, and suppose that maybe the arctic really is too cold, then maybe, just maybe, arctic warming could actually be something good. The arctic might become more livable. Northern lattitudes that previously were just wastelands could become fertile ground for agriculture. The arctic ocean could develop major shipping routes.

Basically what we are talking about here is reducing the temperature variation between northern and southern lattitudes and making the earth a more temperate place. For some reason, warming is presently concentrated at the poles, with very little occuring at the equator which is already arguably too hot. This is actually an ideal situation. It would be far worse if the tropics were becoming hotter while the poles were becoming colder. Moderation is generally good, and in a way we seem to be heading towards a geographically more moderate world with fewer extremes of climate.

Looking at the larger environmental picture, there can be no doubt that life thrives in a climate much warmer than the average of the earth as a whole. The tropics are by far the most fecund region on the planet. Earth is clearly colder today than the optimum for life. Increasing temperatures will increase biomass and improve conditions for life worldwide.

Now, obviously that requires a much larger view than most of us have, including me! I wouldn't want to live in the tropics - too many bugs and other nasties. I don't look forward to the whole planet being that way. But for those of you with a more ecological bent, you should welcome global warming. Even though it may not be ideal for Man, the bugs will love it.

The funny thing is, you frame it so well, I kind of want to agree with you.

Sir! I have a plan!

Mein Führer! I can walk!

Mr. President, we cannot allow a mineshaft gap!


Where to start.

First the greatest increase is at the poles, but the tropics are heating as well.  The energy conveyor systems strips most of the heat out of the tropics and deposits it to the poles.  It is hard to heat up a hot area if that heat is constantly bleeding to colder areas.  How will we know the affect on the tropics until the poles become very much warmer?

Second, I am very tired of people trying to tout the benefits of warm temperatures at high latitudes and altitude.  Just because Ontario Province might have the climate that Iowa used to have doesn't mean you can move all the crops north by 500 miles.  The soils won't allow it.  You can't substitute recent alpine soil for old prarie soil.  Neither can you substitute recent alpine or coniferous forest soil for deciduous forest soil.  They are completely different ecosystems that took centuries to form.

You don't remake an ecosystem in a couple of decades.  You can destroy one in that time, but not make a new one.  Try and remake productive land out of clear cut, eroded, abused, desertified, or strip mined land.  This is very difficult even without a radically changing temperature system.

The natural world, the food web, is a very complex interaction of uncountable organisms all contributing to the stability of that ecosystem.  These interactions took many human lifetimes to become optimized.  You can't change the temperature, or precipitation, or species diversity radically and expect that system to improve in the blink of a geologic eye.  They always become less diverse and less productive from a biological standpoint.  Even the bread basket and midwest U.S. is much less diverse and productive than 200 years ago.  It makes more products that humans value, but is not more biologically productive.  Human impact is the number one cause of desert spreading.  A very warm high latitude land mass is just as (more?) likely to become a cold desert as productive farm land or forest.  

It would be unwise to put this idea on the positive side of the balance sheet of global warming effects, when most past human impacts on environments have not led to that result.

NC -

Fully agree!  

Just because temperatures rise in Alaska doesn't mean that one day you'll be growing pineapples in Fairbanks.  As you quite correctly pointed out, soil composition is a very important part of the equation. The natural soils in the various region took many thousands of years to develop the way they are now, and cannot be change overnight. The soil in the tundra is quite thin and fragile, while the soil in a place like Iowa or the Nile delta is rich and thick as the result of millenia of vegitation and a microbial action.  

As a factor in this whole global balance think, soil is like Rodney Dangerfield - it gets no respect.  When in fact, and if I am not mistaken, there is more biomass in the soils of the world  than in all the aboveground forests and farms, as well as in all the oceans of the world. A cubic inch of rich Iowa soil probably has more biodiversity and also more raw genetic information than you could probably fit on the largest Cray computer.

If we mess of our soils, we've screwed the pooch.

In fact, we are observing vast stretches of Lodgepole Pine dying to pine beetles that are no longer killed by the winter temperatures. Instead the pine beetle swarms get bigger and bigger each year. That's just one single example of the impacts of warming. Those forest will die rapidly but would take decades or even a few centuries to replace, if they can be replaced at all.

And let's not mention the hurricane power growth we've seen so far. Imagine how equatorial coastal regions will fare with the weather when sea surface temperatures are above 90 degrees for months at a time leading to far more Cat 3-5 hurricanes. Also, we're seeing reports that the warming has altered the jet stream and is creating drought and even desert conditions in various regions as we move down towards the equator.

Halfin further conveniently ignores that warming of 10-30 degrees appears to have killed 95% of all species 250 million years ago. Given that the current warming is projected to do at least 8 degrees of increase globally eventually, and that our models are excessively conservative, this doesn't look like a very intelligent thing to do, does it?

Halfin further conveniently ignores that warming of 10-30 degrees appears to have killed 95% of all species 250 million years ago.

if i remember my biology, one of the species that survived that mass extinction(called the permian mass extinction) was the common ancestor of both mammals and dinosaurs.
Dr. Pangloss,
Yes, of course we do live in the best of all possible worlds.
1. Look at opportunities for real-estate development in Greenland--fabulous opportunities there.
2. NW passage open all year around for navigation will help Asians to get more oil from Alberta tar sands via north-flowing pipelines, thus increasing global transportation efficiency.
3. Depopulation of Texas will mean that fewer lawyers get shot there by being mistaken for quail;-)
4. We may find more oil under where all that ice has melted, thereby postponing Peak Oil indefinitely.
5. More open water means more room for Sailorman and his all-girl crew of pleasure boaters.
6. Depopulation of the tropics due to ecocatastrophes solves the Global population probem, thereby removing one big worry.
7. Malaria moving north twenty degrees in latitude will increase the demand for medications, thereby increasing profits for big pharma and thus boosting stocks toward their alltime highs. Invest now, for big profits!
8. Decreased heating bills for U.S. and Canada will increase spending power and send GDP rates soaring up to the bliss point of endless exponential growth, thus proving that all those nattering nabobs of negativism were just a bunch of Chicken Littles.

Ah Dr. Pangloss, where would we be without you.

But there is no place to move now. We must invent a new pattern to survive.

  step back two steps and look at the big picture....

  It seems the Saturn moon Enceladus has some water and the moon Titan has a supply of hydrocarbons.... What would it take to knock these two moons out of their Saturn orbit into orbit around the earth so they could be mined for their resources?
 ...and while you were at it why not move Mars into an orbit opposite the earth.....  ready to terraform and occupy....

  ...coming soon to a new world near you!  martian condos..
purchase incentive   FREE WATER  and FREE GAS!

 wow!  this port is really good!

It seems to me that there is more truth in this view than folks might realize.

Ignoring those who deny climate change is happening or is even possible, people are worried about it because of the possible effects the modified ecosystem will have on our civilization and our lives. Higher sea levels will threaten our coastal cities with flooding. Different weather patterns will result in more severe weather that can damage our infrastructure and take lives. Regions that were once food-producing areas will turn to dust bowls. Etc.

It has been claimed that humans are not to cause of this global warming, that it is just part of a natural cycle. Others claim that it's caused by human activity. It may be that it's a combination of both. It doesn't matter. It is beside the point.

The idea seems to be that climate change is bad and that we want to prevent it from happening. We ask ourselves, "What can we do to prevent global warming?" No matter the cause, this is the question if we assume global warming is a bad thing. The answer is similarly valid whatever the cause: "Maybe something, maybe nothing."

Traditionally, the human-activity camp has argued the former while the natural causes camp has argued the latter. Now it seems that the latter is increasingly the answer from both camps. There's nothing we can do to prevent it, global warming is happening and the climate is going to change.

So now the question for both camps is "What can we do to minimize the effects of global warming?" Again, the answer is "Maybe something, maybe nothing."

In the mean time however, we should be asking ourselves another question: "How do we adapt to climate change?" Given that it is occuring and the only open question is how extreme it is going to be, we should be identifying those areas were change will effect our civilization and how to roll with the impact.

What did you do in the great war Grandpa?

All that understand have a moral duty to act.

From having looked at this whole issue for about 30 years, I was a very science hungry kid. Having studied and developed my own garden designs by age 14 and spending more time writting and thinking than out playing hooky from school.

The Feedback loops have to factor in that while its winter in the North it is Summer in the South.  We have two poles that are covered by ice. 23 degrees of a tilt, and only a short span of time to understand it all in before the system changes to the point that we can no longer live as we do now.

We have several things that are all ramping up at the same time.  Great story making ideas, HollyWood has to sell movies, They can't write the stories Others or I could write.  We can use fact and fiction and have bad endings, bad endings never have sold well to the movie popcorn popping public.

 Population, ice caps, Oil peak, all the things to make a great story, and to scare everyone too.  Right here and right now to a front yard near you.

 The curve is still a straight line, when it does curve, there is not going to be any stopping it, though I really doubt we could stop it now even if we tried,  if we had 5 billion fewer people, if we could just leave here and go elsewhere and let it alone for a few centuries,  maybe the cycle would fix itself.  

I do not think the cycle has only been a few decades in the making,  I would go as far back and the first major uptick in human population and start from there.  But the Worldwide data matrix that you would need might tax even the best computer minds that we have.  Sci-fi Authors have been writting these kinds of stories for years, all the while its been going on right here on earth under our very noses.

It is not over just wait for it.

Quite true that some parts of Australia have
experienced a lot of rain, but the parts where
most people live (especially NSW) are looking
very parched and have been very hot: temperature
anomalies of up to 12 degrees Celsius have been
recorded over the past summer. It is the local
differences that are so unbelievable. Torrents
of rain in one region, but just a few hundred
kilometres away, sever drought (as in East

As for warmer poles bringing advantages, it
might be useful to think how much hotter the
tropical regions might become: India has been
recording mid to high 40s. Temperatures in the
50s appear to be quite possible in the future.
We could well be creating the conditions that
lead to the complete desertification of the
tropical forests of Africa and South America.

Then there is that matter of drought closer to
home. Texas seems to be looking sicker by the
week and if present trends continue will not
have an agricultural sector at all by the end
of this year.

Meanwhile in NZ, a very temperate country which
normally gets plentiful rainfall, there is
currently concern for power generation (hydro),
due to drought.

We had a beautiful nest 50 years ago, but we
have shitted in it. To suggest that more
shitting in the nest might produce benefits
does not make a lot of sense to me.

In practice we are conducting a grand
experiment, for which we cannot predict the
result. But we can make some educated guesses.

This grand experiment actually began in 1850 when Ignaz Semmelweiss invented the technology called "washing your hands".

At a stroke his simple technology removed all protozoan controls on human lifespan.  Global human population graphs went exponential a generation later. Oil was touted as the cause of this, but it seems to me more an invention than a necessity. The real necessity was our sudden surge in effective fertility.

All human civilizations have followed a boom and bust pattern, overbreeding, destroying their agricultural base, falling into savagery, and brutishly moving on. Oil was our way of postponing the fall by leveraging all watersheds everywhere. But there is no place to move now. We must invent a new pattern to survive.

Most likely we will ditch biology. The oceans are turning to acid and our agriculture is growing too expensive to continue. We will dieback. The survivors will be forced to re-engineer their bodies to survive in a toxic, denuded ecosphere. They must become machines to survive.

I imagine metal flowers spreading over the dead earth and electronic voices mimicing the lost birdsong. We are natural creatures so by definition all our technology is natural too. If we are to survive, we must embrace this path - transhumanism - transbiotism - and engineer a new ecosphere in our own image.

That might seem unnatural to you. But your grandchildren might find their robotic bodies as natural as you find cars. After all, pops, what's the alternative?

Beam me up, Scotty!
More like, "Assimilate me, Seven of Nine."
It's happened before. The Archaea, methanogenic prokaryotes, might have been none too pleased by the evolution of cyanobacteria and the rapid poisoning of their atmosphere by consequent oxygen gas.

The vast majority of Archaea were wiped out in that cataclysm. The remainder either evolved to live in places molecular oxygen doesn't occur - extremophiles inside geysers and black smokers - or built great hulking machines around themselves to shelter from the poison.

We call those machines eukaryotes - that's the domain of life you and I occupy. But each of our cells still shelters a degenerate prokaryote called mitochondria. I've made it sound as if this was some kind of intelligent plan on the part of the mitochondria, which of course it was not - just evolution doing its thing. But the point is clear - when your environment changes, you better change with it.

The way forward is Molecular Manufacturing. Beam me up? Nah, no new physics required, nothing but really extremely hard engineering problems to solve. Only real question is whether we can solve them in time.

I canna' do it! My engines are running out of fuel, the power fails . . . I canna' do anything without more dilithium crystals. Ye'll have ta' stay down there forever with the natives.
Well, I did say the engineering problems are really extremely hard ...

No one has the foggiest idea how to command, control, or even orient just a single robot in a physical environment anywhere near as complex and demanding as that of one of Drexler's wild assemblers.

The nanotech guys' counter to this is that, with the advent of assemblers, real AI is just around the corner, and this AI can easily handle the command and control issues of an assembler. Or a pound of assemblers together. No worries. The trouble is this assumes the antecedent - that you can command and control a pound of assemblers well enough for them to express AI in order to create the command and control necessary for their own operation ... Catch-22.

As computer science stands at present we have about as much chance of creating real AI in a pound of assemblers as we have of creating it in a ton of PCs. Which is to say, none. All AI technologies founder on combinatorial complexity under a Turing/Von Neumann computing paradigm.

In other words you can get your expert system/neural net to pull cute tricks in small domains, but the moment you try to scale up, the time and space requirements of your program go exponential. In the last fifty years no one has been able to demonstrate any significant way around this "combinatorial explosion".

So why consider Drexler plausible?

Well, there's been no proof that it's prevented by any physical limits - just engineering ones.

Now say we have 100 years left before we go like yeast in a barrel of hops. 100 years ago was before Tesla hit his straps. Scientific staples like QM and relativity were academic twittery. "Get a horse!" was still heard on the roads. And the electric light was a curiosity that drew crowds. But 100 years ago E.M. Forster published "The Machine Stops", which accurately presaged both the Internet and, after a fashion, Peak Oil.

It's obviously implausible that Star Trek or anything like it has relevance to engineering possibilities today. But basing your judgement of engineering plausibility on the fact that any particular idea has been used in Star Trek is obviously stupid.

With the imminence of practical quantum computing a lot of the old computer science limits are questionable. So Drexler's stuff is still worth going at. It still might not get us there in time to avoid broiling or starving. But hey, pops, what's the alternative?

Trek irrelevant?  As I write this, the History channel is running a show in which Bill Shatner interviews inventors that were inspired by "implausible" technology they saw on a Star Trek series.

I wonder if I could convince my theatre group to stage R.U.R.?