Editore"s Note
Tilting at Windmills

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November 26, 2007
By: Kevin Drum

WORRYING ABOUT WARMING....Cosma Shalizi explains better than I could myself why I've long felt that global warming might be even worse than we think. Nickel summary: I have a bad feeling that f might turn out to be a little bit higher than we think.

But I hope I'm wrong.

Kevin Drum 11:42 PM Permalink | Trackbacks | Comments (67)

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Comments

Global warming is a hoax.

Posted by: pud on November 27, 2007 at 12:13 AM | PERMALINK

Can't say that's the most sophisticated piece of mathematics I've ever seen.

Posted by: matt on November 27, 2007 at 12:17 AM | PERMALINK

Forget the math. Just ask an Inuit.

Posted by: objectivelypro on November 27, 2007 at 12:25 AM | PERMALINK

If Peak Oil hits first, the U.S. as we know it will grind to a halt before the world burns to a crisp.

Lovely thought, eh?

Posted by: SocraticGadfly on November 27, 2007 at 12:30 AM | PERMALINK

That's math for "we're fucked," right?

Posted by: Old Hat on November 27, 2007 at 12:31 AM | PERMALINK

The only thing Mr. Shalizi elides over (which the Science article may not have, I do not have a subscription) is that it assumes (for the sake of simplicity) that all feedback provides an amplification (or out-of-control loop) and there is no higher order damping function that may be present especially upon a large, almost step, perturbation. Again, this may not exist, but needs to considered in the analysis.

Posted by: Kenny on November 27, 2007 at 12:34 AM | PERMALINK

That's math for "we're fucked," right?

Yes.

Posted by: Blue Girl, Red State (aka G.C.) on November 27, 2007 at 12:36 AM | PERMALINK

Two problems here:

1) The overall feedback has to be negative. Otherwise we wouldn't be here. Over geologic time scales the probablity of serious transient disturbances to atmospheric composition is basicly 1.

2) The argument provided can be used against anything. All you have to do is assume three things.
i. The existence of positive feedback in the
system.
ii. Claim you can't be sure some associated
gain isn't around 1.
iii. Claim unbounded negative consequences

You're done! No matter what the topic, your course of action is justified. It's Suskind's 1% doctrine in math.

Posted by: Adam on November 27, 2007 at 12:50 AM | PERMALINK

Adam: You'd be right about (1) if this were a purely natural phenomenon. But it's not.

As for (2), absolutely right. Like I said, I just have a bad feeling about this. That doesn't prove anything, and it may just mean that I'm a worrywart. But for some reason my gut feeling based on everything I've read is that the feedback functions somehow always turn out to be just a little bit bigger than we initially think.

Posted by: Kevin Drum on November 27, 2007 at 12:56 AM | PERMALINK

The original article, which has more info and charts, is here [15 page PDF].

Posted by: JS on November 27, 2007 at 1:02 AM | PERMALINK

An infinite series of tail-biting what now? Would somebody please explain in terms a guy with a cool-weather IQ can understand?

Posted by: Quaker in a Basement on November 27, 2007 at 1:02 AM | PERMALINK

You'd be right about (1) if this were a purely natural phenomenon. But it's not.

There have been the past carbon dioxide levels far more elevated than anything we are experiencing now.

From Wikipedia:

Five hundred million years ago carbon dioxide was 20 times more prevalent than today, decreasing to 4-5 times during the Jurassic period and then maintained a slow decline until the industrial revolution.[14].

Unless there's something truly critical going on today beyond elevated carbon dioxide levels, it's hard to see what is new under the sun here. Certainly everything I've heard about global warming attributes it ultimately to increases in carbon dioxide.

Posted by: frankly0 on November 27, 2007 at 1:05 AM | PERMALINK

The overall feedback has to be negative. Otherwise we wouldn't be here.

Well, the amount of time required for eventual correction might be a little long. Especially if you're talking geological time scales.

I have no doubt the earth will survive. I think mankind will survive. What fraction of the earth's human population dies is up in the air.

Posted by: Wapiti on November 27, 2007 at 1:06 AM | PERMALINK

I don't buy it (and I'm hardly a denialist). If such a feedback system existed and were monotonically positive, we'd already be burning up due to natural variations. I suspect that, in all probability, there are numerous feedbacks, some positive and some negative, with different time constants. Even if you assume that each feedback system is linear, the end result isn't likely to be a continuously increasing temperature. And linearity is unlikely.

(I'd suggest that over geologic time scales, feedback is likely to be negative.)

There is plenty of empirical evidence that warming is occurring, and a fair amount of evidence that suggests that, at least over the short run, it is accelerating. Of all the inputs to the system, greenhouse gas is the one most obviously correlated and, absent some hitherto unknown mechanism, most likely to be causative. Speculation as to feedback phenomena just clouds the issue when as nebulously defined as this.

Posted by: idlemind on November 27, 2007 at 1:13 AM | PERMALINK

I think mankind will survive.

Because why? We like us?

We have some interesting traits but really, there's nothing special about us. We're just as likely to go extinct as anything else, maybe more so considering the really bad behaviour we get up to.

Posted by: craigie on November 27, 2007 at 1:13 AM | PERMALINK

Hmmm. Doesn't take into account tipping points.

frankly0 wrote:
There have been the past carbon dioxide levels far more elevated than anything we are experiencing now.

True. But the conditions then weren't quite amenable to our current lifestyle.

Posted by: josef on November 27, 2007 at 1:17 AM | PERMALINK

Franky0, C02 concentrations from 500,000,000 years ago are not directly germane to how the present day climate will behave.
More useful is data from the last million years, where the current C02 concentration is an anomaly.
And certainly in that time frame, there have been many extreme climate conditions. So while the general climate may have broad boundaries of stability, there are definite instabilities in that envelope.

Plus without historical data outside that envelope, climate models are all we have. That's not an experiment I want to run, unless I get to live on the 'control' Earth.

Posted by: MobiusKlein on November 27, 2007 at 1:23 AM | PERMALINK

True. But the conditions then weren't quite amenable to our current lifestyle.

That's certainly true; I'm not denying that global warming would impose a huge, unnecessary burden on humanity. In general, the worst thing about it seems to be that we've tied ourselves to a pretty stationary infrastructure -- cities on the ocean, agriculture only in certain areas. The damage done to those stationary assets would be pretty terrible.

But I have little doubt we'd survive, even thrive -- we just wouldn't thrive nearly as well as we would without global warming.

Posted by: frankly0 on November 27, 2007 at 1:25 AM | PERMALINK

I think it will take a specialist in this field to interpret this paper. The authors seem to be using standard terminology for their field which they take for granted -- and don't bother to define in detail. (At least that's my impression).

The feedback described, for values of f less than 1, is bounded (and not the general-case positive feedback) because it attenuates with each iteration. (This is a very specific formulation: the feedback described applies only to a single, one-time forcing). For values of f greater than 1, you do indeed get (unbounded) positive feedback.

But again -- I think it will take a climate scientist to explicate the exact meaning and significance of this (I think).

Posted by: JS on November 27, 2007 at 1:26 AM | PERMALINK

A real live meteorologist - with a teevee gig and everything - explains how Carbon Sinks aren't keeping up and why that's a big damned deal.

Posted by: Blue Girl, Red State (aka G.C.) on November 27, 2007 at 1:35 AM | PERMALINK

What makes the situation much more comnplicated is that there are almost certainly more than one f. We probably don't even know all of the possible f's, so that adds more uncertainty, along with not knowing whether, or how much, the situation is linear.

For those who think that the overall feedback is negative, you're probaably correct, but only on a geological time scale. What will likely happen is that a new, hotter equilibrium will be established when some new, negative forcing occurs due to the higher global temperatures such as increases in cloud cover. Or, some new disaster like the explosion of the Yellowstone caldera suddenly introduces a strong negative forcing [volcanic dust and sulfur dioxide]. Or maybe India and Pakistan or Israel decides that a little nuclear winter is a risk they will take for some political point.

- someone who was raised on the Kingston Trio's A Simple Desultory Philippic

Posted by: natural cynic on November 27, 2007 at 1:53 AM | PERMALINK

I am hardly a global warming denier, but the linked post smacks too much like something written by a person who just discovered the concept of instability that can be cause by positive feedback. The fact that such instability may occur is neither a convincing argument that it will happen nor, just by itself, an adequate reason to be alarmed.

Posted by: gregor on November 27, 2007 at 1:59 AM | PERMALINK

I may be missing something, but this entire analysis assumes that the feedback and/or gain in the climate system is a positive number. Of COURSE things will be worse if feedback is a positive number. But most all natural processes are negative feedback processes and/or processes with negative gain or damping. All of this is exactly irrelevant if climate turns out to be in the majority of natural processes, ie has negative feedback.

Posted by: coyote on November 27, 2007 at 2:00 AM | PERMALINK

It seems pretty obvious that the further we advance towards our warmer planet we are moving past various tipping points as we go.

If you made carbolic acid at highschool, you'll know that water only absorbs so much CO2. Longer term, with no new inputs, in the oceans, we can expect that to be absorbed by organisms and make new chalk. The sea, it seems, is nearing saturation right now, and has been ameliorating CO2 effects so far. But not without possible illeefects of pH.

Similarly, tha CO2 we are releasing was captured by vegetation over millions of years. Release is accelerating, not slowing.

Similarly, the methane from the massive peat bogs of the tundra is vegetation captured over time, only to be released if it melts. It's melting.

All snow cover -- glaciers, mountain tops, ice caps -- increase the albedo of the earth. They're going.

Increased cloud cover would lead to blanketing effects, holding more ground heat in.

The airborne particulates are thought to have slowed warming for a while. Now they accelerate it by landing on snow and ice, making it more heat absobing.

I'm sure you can add to the list.

Obviously heat radiation increases as the earth warms, but I don't hear any similar list of countervailing mechanisms that will magically save mankind. God realy is not intrusive.

Surely the denyers could come up with a few negative effects. If there was a real scientist among them.

Of course the earth will go back into balance. When humans aren't forcing the situation animals and vegetation will adapt and continue what they were doing before we upset the apple cart. Capture carbon.

It's pretty easy to get back to a carbon neutral existence without giving up the intelligent side of our life. But this idiot experiment with our existence has to end. Otherwise the proof will be in our demise. We're really not nearly as clever as we think. Just competitively greedy.

Posted by: notthere on November 27, 2007 at 2:29 AM | PERMALINK

Again, the point of the paper is not that positive feedback will make things progressively (and explosively) worse.

Rather, they look at a disturbance in a system and assume that the disturbance has a response that continues for some time until it reaches a limit value (this is what happens when f is less than 1). For a system value that has an initial value of J, the final (limit) value after the disturbance has had its full effect is J/(1-f). This is a finite number, and can be estimated if we have an estimate for f.

What the authors are interested in is the computational sensitivity of such a model to uncertainties in the measurement of the response parameter f. And they say that, even if we improve the precision of our measurement of f, the uncertainty in the resulting total response remains high.

In other words -- if we assume that we change the CO2 concentration by a certain amount, and we can calculate the value of f for the resulting change in mean temperature on the planet, then, no matter how well we can estimate f, our conclusions about the final temperature remain uncertain.

I think what they are saying is -- we cannot trust our models. (Which probably means -- be conservative and stop CO2 emissions aggressively).

Posted by: JS on November 27, 2007 at 2:33 AM | PERMALINK

I didn't look at the link. Don't we already know what we need to do? Both global warming and peak oil point in the same direction, as does any other environmental measure you'd care to examine. We need to get our civilization in balance, and soon. Wouldn't that be more interesting than more of the same?

Posted by: bad Jim on November 27, 2007 at 4:58 AM | PERMALINK

idlemind

James Lovelock, has to an extent, answered the question about what the negative feedback loop is. And he thinks it will kick in (he also thinks we are doomed, at least as a civilisation as we now know it).

The planet (he calls it Gaia-- you and I would call it the earth-biosphere dynamic system) will find its own way to reduce CO2. It will do that, first and foremost, by killing off the majority of the CO2 emitters.

Which happen to be animals. And in particular, one homo sapiens. The temperature will rise, and the factors that cause homo sapiens to die off in numbers and emit less CO2 will kick in: drought, war, famine, disease, mass migration etc. Down to collapse of technology.

The planet will cool off eventually (we're due another such cooling in 12,000 years or so, as the sun shifts to warming the southern hemisphere more, and the ice sheets advance in the northern).

It's just the time scale on which carbon-emitting civilisation works (effectively, since about 1700 and from now to about 2200) is so short that it takes time for the negative feedback to kick in.

Sadly half or more species on the face of this planet will be extinct, and us or many of our descendants will be dead, but from a Gaia-sized perspective, that's OK.

Posted by: Valuethinker on November 27, 2007 at 5:29 AM | PERMALINK

Wait a second! Just last week, Cosma was arguing there was no such thing as "G"!

And here is the histogram of the corresponding values of G, the over-all gain

Posted by: Just One Second on November 27, 2007 at 6:15 AM | PERMALINK

Except that the Gaia hypothesis is anthropomorphizing crap.

What is likely, is that people making money from the status quo, will continue to keep their heads in the sand (and fund advertisizing, marketing, studies, and think tanks to encourage everyone else to do the same) until things get into an entirely bad state.

What I am worried about is the possibility that the yammering assholes have caused a certain amount of self-censorship from people studying this; in order to avoid being "proved wrong" and losing mindshare traction, most people are only publishing their most conservative results. There have been a few apocalyptic publications (did you see that one talking about what happens if the oceans starting outgassing sulfides?) but that stuff doesn't get near the press of even that single hoax "blame the bacteria" anti-GW paper. Arctic icecap melting is exceeding predictions; Greenland glacier movement is exceeding predictions -- statistically, if these guys were targeting the truth (instead of conservatively holding their fire) we'd expect to see a couple of big blown predictions.

Posted by: dr2chase on November 27, 2007 at 8:50 AM | PERMALINK

There are actually several feedback mechanisms going on with global warming.

One, since CO2 is a "heavy gas" it does not readily "evaporate" into space, but instead remains in the atmosphere. As additional CO2 is generated, it remains in the atmosphere.

Whether or not you consider that a "feedback mechanism, the other two are. With warming of the atmosphere due to accumulation of CO2, the atmosphere can take up more water vapor from the oceans. Water vapor is also a greenhouse gas and probably the primary one. That will further enhance global warming.

Moreover, global warming will enhance the generation of methane from rotting plants that were previously frozen. Methane is also a greenhouse gas, although probably of lower importance than water vapor or CO2 in the scheme of things.

Oh, yes, there is a feedback loop.

Posted by: raj on November 27, 2007 at 9:23 AM | PERMALINK

Isn't equilibrium climate sensitivity a function of starting conditions?

I wouldn't be worried so much about CO2 emissions if we didn't have a northern hemisphere ice cap, continental glaciers, permofrost, and a bunch of frozen methane and labile organic carbon in the shallow oceans. And I wouldn't worry so much about that if we hadn't built a complex global infrastructure for 6.6 billion people requiring fairly predictable climatic conditions across broad portions of the planet where we conduct agriculture.

Posted by: B on November 27, 2007 at 10:29 AM | PERMALINK

...maybe India and Pakistan or Israel decides that a little nuclear winter is a risk they will take for some political point.
Posted by: natural cynic on November 27, 2007 at 1:53 AM
----------
We've got a good-sized stockpile of thermonuclear weapons. We just need to get out the slide-rules and figure out just how much high-stratosphere dust needs to be thrown up there to cool us off for a couple of decades. Set off some controlled nuclear explosions in just the right spots every 10-20 years while we work on reducing the carbon output into the atmosphere. I'm being a bit snarky, but I wouldn't be surprised that is what ends up happening.

Posted by: Doc at the Radar Station on November 27, 2007 at 10:52 AM | PERMALINK

This paper has been pretty thoroughly discussed in the field, by climate sensitivity specialist James Annan:

http://julesandjames.blogspot.com/2007/10/roe-and-baker.html

and RealClimate:

http://www.realclimate.org/index.php/archives/2007/10/the-certainty-of-uncertainty/

Funny how the climate question is almost the reverse of the real estate question. In real estate, it's how low can the market go? In climate, it's how high will the global mean go?

But in neither case does it look good.

Posted by: Kit Stolz on November 27, 2007 at 11:07 AM | PERMALINK

Adam nailed it. Shalizi's article is based on unvalidated assumptions. His model has not been shown to apply to actual weather patterns. His result is like the religious argument that goes:

Even if you're not sure about the existance of God, you should avoid sin so as to avoid even a tiny risk of eternal damnation.

Similarly, Cosma Shalizi argues that

Even if we're not sure about how global warming works, we should make public policy to avoid even a tiny risk of making the earth uninhabitable.

The trouble is, we don't know what policy to follow. Merely switching to more efficient cars and other changes here in the US will have little effect on atmmspheric CO2. Most of the growth in CO2 is coming from China and India. If one really believes the future of mankind is at stake, maybe we should destroy those two countries with a surprise nuclear attack. That's obviously ridiculous.

Furthermore, it would be easy to make up other models that would call for vastly different actions to prevent global warming. We can't simultaneously change in many different directions.

Those who claim to be most worried about global warming don't behave that way. John Edwards and Al Gore have enormous mansions. John Kerry has 6 of them. The UN is planning a 2 week boondoggle in Bali to address global warming, from Dec. 3 - 14. With so many people from different parts of the globe flying all the way to Bali, this meeting will have an enormous carbon footprint. (Not to mention the hot air from the speakers.) They talk the talk but won't walk the walk.

Posted by: ex-liberal on November 27, 2007 at 11:11 AM | PERMALINK

dr2chase wrote: "Except that the Gaia hypothesis is anthropomorphizing crap."

No, Lovelock's Gaia hypothesis is most certainly not "anthropomorphizing crap."

There is nothing whatsoever "anthropomorphic" about Lovelock's hypothesis that the chemical disequilibrium of the Earth's atmosphere is created, regulated and maintained by the Earth's biosphere.

Lovelock arrived at this hypothesis when he was asked to study the atmospheres of Mars and Venus to see if anything could be learned from their chemical makeup that might indicate the presence or absence of life. He found that on those planets the atmosphere is in chemical equilibrium with the geosphere -- in other words the gas chemistry of the atmosphere had interacted with the mineral chemistry of the surface over many millions of years until they were in a stable chemical equilibrium.

In contrast, the Earth's atmosphere is in chemical disequilibrium with the Earth's geosphere. Since chemical interaction of the atmosphere and the geosphere over the long term would produce chemical equilibrium, something else must be affecting the chemical composition of the atmosphere to maintain the state of disequilibrium. Lovelock's "Gaia" hypothesis was that the Earth's biosphere -- life -- is the agent that actively maintains the Earth's biosphere in a state of chemical disequilibrium.

Lovelock concluded that the chemical equilibrium of the Martian and Venusian atmospheres therefore indicate the absence of life on those planets.

Lovelock's original hypothesis further suggests that the Earth's biosphere as a whole actively modifies the Earth's atmosphere to maintain an environment that is hospitable to the presence of life, and I think it is fair to ascribe to Lovelock's "Gaia" hypothesis the concept of the Earth's biosphere-atmosphere-hydrosphere as a self-regulating biological entity.

But as biologist Lewis Thomas wrote in Lives Of A Cell, this entity more resembles a cell than it does an organism -- let alone a human being. We can describe a living cell, for example an amoeba, as a self-regulating living entity without being accused of "anthropomorphizing" it; and we are no more "anthropomorphizing" the Earth system by suggesting that it is a self-regulating living entity than by saying the same thing about a cell.

Nothing in Lovelock's "Gaia" hypothesis ascribes human characteristics to the Earth's biosphere, which is the meaning of "anthropomorphizing" (the term originally referred to the theological fallacy of attributing human characteristics to god).

In particular nothing in his hypothesis suggests or implies that the Earth's biosphere has capabilities of intentionality such as "choosing" to rid itself of harmful "pathogens", eg. CO2 emitting life forms that threaten the viability of the biosphere through rapid and extreme heating of the atmosphere.

Certainly others have taken Lovelock's "Gaia" hypothesis as an inspiration to "anthropomorphize" the self-regulating living entity that Lovelock hypothesized the Earth's biosphere-atmosphere-hydrosphere system to be. But that's not Lovelock's fault. Indeed the name "Gaia hypothesis" was not even Lovelock's idea; it was suggested to him by a friend.

I think the importance of Lovelock's views on global warming is not in his admittedly compelling metaphors (that the biosphere is "running a morbid fever") or in his (in my opinion misguided and ill-informed) prescriptions for solutions (eg. a huge expansion of nuclear power) but in his unique understanding that the Earth's biosphere-atmosphere-hydrosphere is a whole system and that global warming is likely to trigger synergistic, systemic responses from that whole system.

This is in contrast, for example, to the observations of many climate scientists who tend to look at particular pieces of the picture in isolation.

And I tend to think that Lovelock is right in expecting that these synergistic responses of the whole Earth system will bring much worse consequences from global warming than are being talked about by mainstream climate scientists.

Posted by: SecularAnimist on November 27, 2007 at 11:14 AM | PERMALINK

Unless there's something truly critical going on today beyond elevated carbon dioxide levels, it's hard to see what is new under the sun here. Certainly everything I've heard about global warming attributes it ultimately to increases in carbon dioxide. Posted by: frankly0

Except that water vapor, which is able to trap more heat than carbon dioxide, is increasing in the stratosphere as well. Then add all the bovine, ovis, and career politician flatulence driving up the methane levels, and you have a upper atmosphere cocktail perfect for raising the globe's average temperature.

Why won't Dick Cheney die?

Posted by: JeffII on November 27, 2007 at 11:22 AM | PERMALINK

And I tend to think that Lovelock is right in expecting that these synergistic responses of the whole Earth system will bring much worse consequences from global warming than are being talked about by mainstream climate scientists.

I think I would rephrase that as "if we change the earth a lot quickly, the weed species (opportunists and fast evolvers) will move in at all levels, and who knows what the heck they will do. It sure as heck isn't in anyone's model". "Worse consequences" might include the hydrogen sulfide Permian extinction hypothesis.

But I see no intent, no particular need for an equilibrium, and no particular synergy. Life will continue in its generally greedy path wherever it can, and what remains will be the bits that can survive the conditions that they create. Which is to say, viewing it as a chaos of tactical and strategic greed, gives me more insight than "regulated and maintained by the biosphere". Lovelock's phrasing makes it sound like it wasn't a very lucky accident.

Posted by: dr2chase on November 27, 2007 at 11:34 AM | PERMALINK

I think I would rephrase that as "if we change the earth a lot quickly, the weed species (opportunists and fast evolvers) will move in at all levels, and who knows what the heck they will do.

Ages ago I came across a paper, and now I can't find the reference, but there is a "living lab" in a Colorado alpine meadow. The researcher brought in lamps and raised the temperature over the area by a couple of degrees. The change was obvious - weed species and woody species commenced to thrive, and succulents and wildflowers were choked out.

Anyone else know what I'm talking about? I can't find the link, but I'll keep looking.

Posted by: Blue Girl, Red State (aka G.C.) on November 27, 2007 at 11:42 AM | PERMALINK

Set off some controlled nuclear explosions in just the right spots every 10-20 years while we work on reducing the carbon output into the atmosphere. I'm being a bit snarky, but I wouldn't be surprised that is what ends up happening. Posted by: Doc at the Radar Station

Remember what the eruptions of Krakatoa and St. Helens did for about 18-months?

I think a better bet would be to use the largest non-nuclear bombs and jump-start a few volcanic eruptions on some isolated areas in Kamchatka (yes, I know that's redundant), Alaska (preferably near Ted Stevens, Lisa Murkowski and Don Youngs houses), and an island yet to be named in the Southern Pacific or Atlantic. Probably work about as well as GM's betting on building a hydrogen fueled vehicle by 2020 or whenever the hell they think they'll be able to do it.

What a fucking joke we are as a post-industrial society. We built four atomic bombs pretty much from scratch in three years or so with slide rules and graph paper.

Declare war on the environment and we should be able to lick the problem in less than a decade. The EU is way ahead of us already, and we could easily shame the Japanese into getting off the dime. We just need to taunt them by saying they aren't up to it technologically or industrially, which of course they are. The S. Koreans would fall into line not wanting to be left behind again. That really leaves only the Chinese. Next Great Leap Forward anyone?

Posted by: JeffII on November 27, 2007 at 11:45 AM | PERMALINK

SecularAnimist,

I generally agree with much of what you write, but you must admit that phrases such as The planet (he calls it Gaia-- you and I would call it the earth-biosphere dynamic system) will find its own way to reduce CO2. sound like anthropomorphizing.

I know it was not you that said it that way. Giving the planet a name and talking about the planet 'finding its own way' sure sounds like a way to say the planet has intentionality.

Personally I don't think we can depend on the planet finding its own solution. We created this problem, we need to fix it.

Oh, and popping off a couple tachtical nukes to create a dust cloud sure sounds like something from a movie of the week and not a real solution.

Posted by: Tripp on November 27, 2007 at 11:55 AM | PERMALINK

I don't doubt that the current spread of temperatures estimated by the IPCC is too optimistic. The IPCC report is a product of consensus grimly batted out in infinite committee meetings. This summer's precipitous and unexpected decline in Arctic sea ice spoke of terrible things in wait. But there's simply not enough carbon available to manage the kind of changes envisioned in that article. We'll eventually get around to burning the coal, oil shales, and tar sands, but most of the carbon from archaic atmospheres is in calcium carbonate -- sea shells.

Posted by: Jeffrey Davis on November 27, 2007 at 12:04 PM | PERMALINK

JeffII, We had a thread here about a couple of months ago where this was discussed quite a bit. I believe another poster (Valuethinker) said that volcanoes can cool things off but just for a few short months. Nuclear weapons OR cities burning (as in WWII) plumes the aerosols much higher and that produces a cooling effect that is 10-20 years. I'll try to find the links.

Posted by: Doc at the Radar Station on November 27, 2007 at 12:10 PM | PERMALINK

"There have been the past carbon dioxide levels far more elevated than anything we are experiencing now."

Yeah, but solar output was lower in the Ordovician, Jurassic, etc. We've been able to hindcast conditions in the Ordovician (12x current CO2 levels, lower solar output, most of Earth land mass glaciated) using GCM models for about a decade now.

Posted by: Sock Puppet of the Great Satan on November 27, 2007 at 12:15 PM | PERMALINK

Here's a graph of the global temperature anomaly since 1880.
(Check out the cooling between 1945-1980)

Here's a nuclear winter study that Rutgers did.

Posted by: Doc at the Radar Station on November 27, 2007 at 12:20 PM | PERMALINK

"but most of the carbon from archaic atmospheres is in calcium carbonate -- sea shells."

If we succeed in altering the pH of seawater and meteoric water we might be able to get some more of that CO2 too!

Posted by: B on November 27, 2007 at 12:25 PM | PERMALINK

With so many people from different parts of the globe flying all the way to Bali,

I'm curious -- what spot on Earth would you not have to "fly all the way to" in order to make it accessible to people from all around the globe?

Posted by: Stefan on November 27, 2007 at 12:31 PM | PERMALINK

raj -

Moreover, global warming will enhance the generation of methane from rotting plants that were previously frozen. Methane is also a greenhouse gas, although probably of lower importance than water vapor or CO2 in the scheme of things.

Oh, yes, there is a feedback loop.

I'm sorry to report that methane is probably not of lower importance - not at 15-20x effectiveness at trapping heat. http://www.epa.gov/methane/

If we get to the point that most of the soil-sequestered methane begins to release, we will almost certainly see an acceleration of warming. I don't even want to think about the methane hydrate trapped at the oceans' floors.

Therein lies your feedback loop - CO2 concentrations raise temps which increase water vapor levels which raise temps which lead to methane release which leads to increased temps which leads to beachfront property in the Berkshires!! (aka - 3. Profit!!!)

Posted by: kenga on November 27, 2007 at 12:33 PM | PERMALINK

Tripp wrote: "... phrases such as 'The planet (he calls it Gaia-- you and I would call it the earth-biosphere dynamic system) will find its own way to reduce CO2' sound like anthropomorphizing. I know it was not you that said it that way. Giving the planet a name and talking about the planet 'finding its own way' sure sounds like a way to say the planet has intentionality."

I agree that such language -- attributing "intentionality" to the Earth's bio-atmo-hydro-sphere a.k.a. "Gaia" -- is anthropomorphic. But such language goes beyond Lovelock's original Gaia hypothesis that the Earth's biosphere actively and continually modifies the chemical content of the atmosphere and that the whole system of the biosphere-atmosphere-hydrosphere may be conceived of as a self-regulating living entity.

Some people seem to have difficulty understanding or accepting the possibility of a self-regulating system that maintains a dynamic state without "intention" to do so.

And there is no reason to assume that the Earth's biosphere will "find its way" to reducing CO2 levels, intentionally or not. The biosphere might just as easily adapt over time to higher concentrations of CO2 and a hotter planet, although this might not result in a biosphere that is hospitable to the human species, let alone human civilization. For that matter, continued rapid and extreme anthropogenic increases in CO2 levels and the resulting rapid and extreme warming might outstrip the capacity of "Gaia" to either modify the atmosphere or adapt, leading to a global mass extinction such as occurred at the end of the Permian when 95 percent of life on Earth was wiped out, and it took millions of years for a rich, diverse -- and quite different -- biosphere to regrow.

Posted by: SecularAnimist on November 27, 2007 at 12:36 PM | PERMALINK

Nuclear weapons OR cities burning (as in WWII) plumes the aerosols much higher and that produces a cooling effect that is 10-20 years. I'll try to find the links. Posted by: Doc at the Radar Station

You can't get much higher in the atmosphere than the ash plumes from the Krakatoa and St. Helens eruptions. St. Helens' went an estimated 60,000' into the atmosphere. The ash plume for Krakatoa's eruption, occurring when it did, wasn't measurable, but was assumed to be as high or higher than St. Helens' and more voluminous due to the range of the fallout and the effect it had on the weather throughout the world.

There is no such thing as a "controlled" above ground nuclear detonation. What are you going to do with the radiation? Also, you've got to drop it on something to create a debris funnel. While I know most of the trolls here would be willing to "sacrifice" any number of cities around the world (including some here in the U.S.), my idea is a fantasy, yours is a nightmare.

Posted by: JeffII on November 27, 2007 at 12:46 PM | PERMALINK

We've been able to hindcast conditions in the Ordovician (12x current CO2 levels, lower solar output, most of Earth land mass glaciated) using GCM models for about a decade now.

I've got to believe that basically what this means is that GCM have been so designed that they can "predict" some phenomena in those eras. It's hardly as if the GCM have had some kind of independent strong verification; I'm sure it's a basic constraint on the acceptability of a GCM that it make such "predictions".

While I appreciate that this is about the best science can do under the circumstances, it's always hard to take without a grain of salt predictions based on a model whose only real verification is that it has done a decent job "predicting" already known points, and which was indeed designed under the constraint that it might do just that.

In general, I'd expect that there are a vast variety of possible models that would "predict" correctly past climates. Some of those would predict one thing, some another, for our future. There are probably no real constraints that would force us to conclude that one or the other must actually be correct.

In general, it would seem such models are only worse than economic predictions -- at least economic models can make genuine, future predictions, and have them tested against reality. Of course, such models often fare very poorly when put to this ultimate test, however nicely they might "predict" the past.

I guess I'd like to see some evidence that predictions about climate are more reliable than those about economics. Are climate systems really that much simpler than economic systems?

Posted by: frankly0 on November 27, 2007 at 1:12 PM | PERMALINK

JeffII, using nuclear detonations to kick up aerosols into the stratosphere to cool the planet aren't viable just because of radiation concerns, but because of the effect on ozone:

"While temperatures at Earth's surface would drop, those in the stratosphere would increase by 30°C or more for at least 3 years, says Michael J. Mills, an atmospheric scientist at the University of Colorado at Boulder. At those higher temperatures, the large quantities of nitrogen oxides formed during the nuclear explosions—when nitrogen in the air literally burns—would destroy high-altitude ozone at rates much higher than normal, he notes."

Posted by: Doc at the Radar Station on November 27, 2007 at 1:18 PM | PERMALINK

The time constant over which warming occurs is more important than the final steady state change in temperature.

A large change (say 8C) over a long (say 100 - 200 years) time period would probably be without major consequences.

A small change (say 3 C) over a short time period (say 10 years) would probably be expensive as hell.

As a side note, the better the models get, the less we have to worry about the effects of climate change. Our infrastructure is constantly being renewed and accurate predictions would allow us to build for the future, not the present.

BTW, the Gaia hypothesis, as it was being cited in the posts above, is unsupportable.

Asserting that the Earth's biosphere is in a dynamic equilibrium is one thing. Asserting that Earth "actively" maintains homeostasis is absurd.

Posted by: Adam on November 27, 2007 at 1:44 PM | PERMALINK

In general, I'd expect that there are a vast variety of possible models that would "predict" correctly past climates.

Past climates have not been "predicted," they have been described. In other words, we know what life on earth was from fossil and other records of different eras.

I guess I'd like to see some evidence that predictions about climate are more reliable than those about economics. Are climate systems really that much simpler than economic systems? Posted by: frankly0

Who said any of this was simple? And economics is not science precisely because it's rooted in human behavior for which there are no constants. No one has been able to successfully model this (see histories of the Soviet Union and PRC).

The overwhelming majority of the world scientific community shares the conclusions about global warming, which is based on hard scientific data that can be modeled. Even if there is a 5-10% variable, which is exceedingly high in science, things are going to change dramatically over the next 50-100 years. If you don't believe this, I say go for it! Get that place in the Seychelles or Mauritius.

Posted by: JeffII on November 27, 2007 at 1:45 PM | PERMALINK

JeffII,

Look, I'm not disputing that, most likely, global warming is now taking place and that it's due to human intervention. I can understand that there is an increase in greenhouse gases, that those certainly seem to be able on very basic principles to increase temperatures, and that, in fact, we are experiencing an increase of temperature, which has very bad effects.

What I find difficult to believe, though, is that we are entitled to great certainty in our conclusions here. I just don't believe we have enough understanding of these complex processes to pretend to true certainty.

Now, of course, we don't need certainty to take corrective action here, anymore than we need to know that we are about to have a car crash to put on seat belts.

I'm especially sceptical of claims that our current global warming is wholly unlike anything the earth has seen before in its multibillion year history, and that civilization is doomed if we don't correct it now. I just don't see how any model making such a long term and radical prediction could possibly have anything like strong verification.

And, again, I'd like to see some real explanation of why climate models are inherently much simpler and more credible than economic models. While human behavior is complicated, economists argue that economic incentive, and the laws of supply and demand, etc., can abstract away from those complexities. Climate models inherently involve complex, interacting chemical processes, and, worse, organic processes. Why this might be vastly simpler I can't say I can begin to understand.

Posted by: frankly0 on November 27, 2007 at 2:07 PM | PERMALINK

His post is an absolutely fabulous example how one can write an article where most every line is literally true, but the conclusion can still be dead wrong because one tiny assumption at the beginning of the analysis was incorrect (In this case, "incorrect" may be generous, since the author seems well-versed in the analysis of chaotic systems. A better word might be "purposely fudged to make a political point.")

Actually, I can think of two unstated facts that undermine this analysis.  The first is that most catastrophic climate forecasts you see utilize gains in the 3x-5x range, or sometimes higher (but seldom lower).  This implies they are using an f of between .67 and .80.  These are already very high numbers for any natural process.  If catastrophist climate scientists are already assuming numbers at the high end of the range, then the point about uncertainties skewing the gain disproportionately higher are moot.  In fact, we might tend to actually draw the reverse conclusion:  That likely over-statement errors in f are over-stating the gain by an even greater degree, implying not that things are likely worse than predicted, but in fact that current forecasts are over-stated by more than we might actually suspect.

But here is the real elephant in the room:  For the vast, vast majority of natural processes, f is less than zero.  The author has blithely accepted the currently unproven assumption that the net feedback in the climate system is positive.  He never even hints at the possibility that that f might be a negative feedback rather than positive, despite the fact that almost all natural processes are dominated by negative rather than positive feedback.  Assuming without evidence that a random natural process one encounters is dominated by negative feedback is roughly equivalent to assuming the random person you just met on the street is a billionaire.  It is not totally out of the question, but it is very, very unlikely.

When one plugs an f in the equation above that is negative, say -0.3, then the gain actually becomes less than one, in this case about 0.77.  In a negative feedback regime, the system response is actually less than the initial perturbation because forces exist in the system to damp the initial input.

The author is trying to argue that uncertainty about the degree of feedback in the climate system and therefore the sensitivity of the system to CO2 changes does not change the likelihood of the coming "catastrophe."  Except that he fails to mention that we are so uncertain about the feedback that we don't even know its sign.  Feedback, or f, could be positive or negative as far as we know.  Values could range anywhere from -1 to 1.  We don't have good evidence as to where the exact number lies, except to observe from the relative stability of past temperatures over a long time frame that the number probably is not in the high positive end of this range.  Data from climate response over the last 120 years seems to point to a number close to zero or slightly negative, in which case the author's entire post is irrelevant.   In fact, it turns out that the climate scientists who make the news are all clustered around the least likely guesses for f, ie values greater than 0.6.

Incredibly, while refusing to even mention the Occam's Razor solution that f is negative, the author seriously entertains the notion that f might be one or greater.  For such values, the gain shoots to infinity and the system goes wildly unstable  (nuclear fission, for example, is an f>1 process).  In an f>1 world, lightly tapping the accelerator in our car would send us quickly racing up to the speed of light.  This is an ABSURD assumption for a system like climate that is long-term stable over tens of millions of years.  A positive feedback f>=1 would have sent us to a Venus-like heat or Mars-like frigidity eons ago.

Posted by: coyote on November 27, 2007 at 2:17 PM | PERMALINK

I guess I'd like to see some evidence that predictions about climate are more reliable than those about economics. Are climate systems really that much simpler than economic systems?

They could be. The problem with economic predictions, unless you keep them a secret, is that the economic actors are influenced by the predictions, which is a recipe for booms and busts. The weather/climate is not influenced by predictions.

I'm especially skeptical of claims that our current global warming is wholly unlike anything the earth has seen before in its multibillion year history, and that civilization is doomed if we don't correct it now.

We have seen climate change in the past that would "doom" (or at least badly damage) civilization. Snowball earth, the hypothesized Permian sulfide cloud, even plain old ice ages. I live down the road from streets called Moraine and Agassiz; not so many millenia ago, there was a thousand feet of ice where I am sitting now. I grew up in Florida, which has variously been about a factor of 5 larger and smaller depending on the sea level.

Posted by: dr2chase on November 27, 2007 at 2:25 PM | PERMALINK

GCMs are "tuned" by improving the physics involved.

Posted by: Jeffrey Davis on November 27, 2007 at 2:28 PM | PERMALINK

I'm especially sceptical of claims that our current global warming is wholly unlike anything the earth has seen before in its multibillion year history, and that civilization is doomed if we don't correct it now.

Who is making that claim?

There are reasons -- proxy studies -- to point out that temps are higher than anyime in the last 1000 years. And probably 2000 years. There are ice core records to match against CO2 and temps. As a result, they can graph concentrations of co2 and temps back hundreds of thousands of years. They can assert convincingly that at no time during that span has CO2 increased so abruptly. And that current levels are unprecedented for hundreds of thousands of years. (Perhaps you were simply being hyperbolic in your span of time. It's hard to hear hyperbole in a discussion marked by mis-statements of facts.)

The important thing to keep in mind is that we've never had CO2 this high since homo sapiens appeared on the scene 70,000 years ago. And we sure haven't had either temps or CO2 this high since civilization came down the pike 4000-5000 years ago. And with > 6 billion of us? Forgetaboutit. We're in virgin territory here. Droughts, floods, advancing diseases, and rising sea levels don't make you squeamish? Get off the meds. They should.

We have seen climate change in the past that would "doom" (or at least badly damage) civilization. Snowball earth, the hypothesized Permian sulfide cloud, even plain old ice ages. I live down the road from streets called Moraine and Agassiz; not so many millenia ago, there was a thousand feet of ice where I am sitting now. I grew up in Florida, which has variously been about a factor of 5 larger and smaller depending on the sea level.

The stuff you blow off came well before modern civilization.

Posted by: Jeffrey Davis on November 27, 2007 at 2:38 PM | PERMALINK

A large change (say 8C) over a long (say 100 - 200 years) time period would probably be without major consequences.

8C would melt the ice in Greenland and West Antarctic. Sea levels would rise 20m or more.

20m even spread over 200 years would be precipitous as hell. Even if the melt were meted out equally that would be ~4" of sea level rise per year. Storm surges would be more. Encroaching sea water would spoil aquifers. Foundations would crumble. Etc. 4" per year, relentlessly, over 200 years wouldn't be cinematic but it would be a 1st class natural catastrophe dwarfing any other natural calamity we've gone through in history.

Posted by: Jeffrey Davis on November 27, 2007 at 2:44 PM | PERMALINK

I'm especially sceptical of claims that our current global warming is wholly unlike anything the earth has seen before in its multibillion year history, . . .

Yes and no. Yes, it is well-documented that the earth has experienced enormous climate shifts, but they took thousands if not tens of thousand of years to occur. So, no. The current predicted climate shift is unlike anything seen or identified before because it is happening so quickly.

. . .and that civilization is doomed if we don't correct it now.

That's pretty much a given if you accept the predicted changes because temperatures will rise, sea levels will rise, and because agricultural land will decrease. Add the end of oil to this (wonderful timing), and it's pretty difficult to imagine the continuation of the life I grudgingly accept as the best mankind can produce. Dude, do you know that there were three viable ski areas in Arizona up until about ten years ago?

And, again, I'd like to see some real explanation of why climate models are inherently much simpler and more credible than economic models. Posted by: frankly0

And, again, who said they are simple? You're the only one in this thread saying that it's all so simple. If it's so simple, why haven't you written something like Global Warming For Dummies?

I'll address your idiotic comparison to the "dismal science," which I spent a lot of time in grad school learning, by simply saying that economics has elegant explanations for just about everything when people act rationally and reasonably. However, I only have to point to our nation's current economic woes to disabuse you of the notion that these explanation are all that sound because far too many people behave irrationally and unreasonably, often times (mortgage brokers, bond raters, Republicans and other Hummer owners, pay attention here) on purpose.

Posted by: JeffII on November 27, 2007 at 3:15 PM | PERMALINK

JeffII: economics has elegant explanations for just about everything when people act rationally and reasonably

Elegant explanations for fantasy land? That's useful.

Posted by: alex on November 27, 2007 at 3:46 PM | PERMALINK

coyote

Climate is long term stable. Climate under the parameters in which homo sapiens has experienced them is anything but long term stable.

The Holocene period is an unusual one, at least in the last few million years, of such stable temperatures.

But a world 5 or 6 degrees centigrade warmer than the one we have now is very unlikely to be able to sustain 9-10 billion of us (as we will be by then). Nor are our political systems likely to prevent war, and possibly nuclear war, in competition as populations migrate, shift, and die.

And of course the speed of transition is fast enough to cause mass extinction. As the colony bee disorder has shown, we don't know what our dependence is on these creatures, until they go extinct on us.

As we move into the Anthropocene era, we are quite capable of producing temperatures that our civilisation will not sustain at. Climate change is implicated in the collapse of many civilisations, and these were civilisations that didn't have nuclear weapons.

My point about Gaia was simply that it may be that the earth biodynamic system (life) has ways of reducing our impact on the system: in the growth of bacteria in a pond, the population at T, the maximum sustainable population, is twice what it is at time T-1. And at T+1, it can be 10% of what it is at T. Or 1%.

Life may simply respond to the problem of global warming, by making all but a couple of hundred million of us extinct.

Posted by: Valuethinker on November 27, 2007 at 5:30 PM | PERMALINK

How ironic if the damping factor in the oscillatory system we are looking at might be mass human death.

In the sense that avian flu is certain, and will cause a significant fall in human economic activity, that might be the first harbinger of it (say 0.1-1.0% of the world population dead, and GDP falls by 5-10%).

Posted by: Valuethinker on November 27, 2007 at 5:32 PM | PERMALINK

Positive feedback, negative feedback, pleeze!

What's the phase response of the loop gain? How linear is the feedback? Is the feedback function monotonic? How many local minima and maxima? Where does the first bifurcation happen? What are the noise levels?


This whole global weather system is a lot more complicated then just "positive feedback."

So we don't know.

Posted by: Joey Giraud on November 27, 2007 at 11:25 PM | PERMALINK

>Sadly half or more species on the face of this planet will be extinct, and us or many of our descendants will be dead, but from a Gaia-sized perspective, that's OK.

Extinguishing many people and condemning them to poverty is ultimately the solution championed by climate warming alarmists, although they pretend we can survive with style. Rather than do it to ourselves with certainty, I say roll the dice - particularly since the likelihood of catastrophic change is laughably small.

BTW, the conclusions about climate warming are NOT based on scientific data that can be modelled. The conclusions are based on outputs of models which partly use scientific data for inputs. That is a subtle but important difference. It is not in dispute that complex non-linear systems can not currently be accurately modelled; such systems can only be approximated and the question is whether the approximation is stable and accurate enough. Since the models are invariably sensitive to small perturbations - slight changes in inputs cause complete garbage to spew out the other end - the only way to approximate reality is to retrofit a bunch of tweaks to the (sensitive and poor) models. It is the modelling equivalent of the "begging the question" fallacy. The model ends up assuming whatever it must to reach the intended conclusion.

Posted by: VRWC on November 28, 2007 at 10:39 AM | PERMALINK

VRWC, I try to avoid such language nowadays, but your comments can charitably be described as those of either an ignorant dumbass or a deliberate liar.

VRWC wrote: "Extinguishing many people and condemning them to poverty is ultimately the solution championed by climate warming alarmists, although they pretend we can survive with style."

On the contrary, unabated anthropogenic global warming will extinguish many people and condemn them to poverty. Indeed the effects of climate change are already having catastrophic consequences for millions of people in the developing world, and these effects are accelerating rapidly.

The industrialized countries whose carbon emissions over the last century created the problem -- particularly the USA -- have a responsibility to take the lead in reducing emissions in order to avoid death and starvation for billions of people in the developing world.

VRWC wrote: "BTW, the conclusions about climate warming are NOT based on scientific data that can be modelled."

Your comments about climate models are nonsense. You don't have the slightest idea what you are talking about. You are regurgitating scripted, Exxon-Mobil-funded, pseudoscientific denialist propaganda.

Posted by: SecularAnimist on November 28, 2007 at 10:55 AM | PERMALINK

>On the contrary, unabated anthropogenic global warming will extinguish many people and condemn them to poverty.

Those are all wild-ass guesses. Sorry, but that's all. No one really has a clue what to expect from a warmer world, if one should ensue. Pretending that claims of disaster bear any resemblance to facts or reasonable expectations is just intellectual dishonesty. Do you cheat yourself at solitaire, too?

>Your comments about climate models are nonsense.

No, those are simply factual statements about models of complex dynamic systems. There's no controversy about the limitations of computer models. If there's any denial in the climate change argument, it exists primarily among people like you who refuse acknowledge basic realities.

Posted by: VRWC on December 1, 2007 at 8:56 PM | PERMALINK




 

 

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