Finem Respice takes on a number of the insider responses of the “nothing to see here, move along” type. My favorite:
“The language used by scientists in the emails in question is indicative of scientists under a great deal of political pressure from the outside.”
The heart bleeds with an anguish and despair so palpable, so imbued with the darkly iridescent and sickly sweet venom of suffering that it is plainly visible out to 50 meters as a colorful aura, brightly fluorescing through the ribcage, glowing like a beacon of sorrow to any empath with the skill level of a Freshman at Vassar who thinks she remembers once reading a book on shamanism.
As a group one rarely sees scientists (or, indeed, any vocational group other than politicians) so deeply in love with the by-hook-or-by-crook of politics, the grand import of jetting off to Nice for the next climate meeting and the limelight that accompanies all these world-saving goings on as those few, those lucky few exposed in the CRU emails. (Just throw in a bit of expense scandal and you might as well be in the House of Commons- oh, wait a second….) It is all but impossible not to come away with a sense of what is plainly a naked lust for naked ambition simply oozing out of those texts. I am utterly devoid of sympathy for any such that later claim to have been forced to compromise their composure, their decorum or their data because of the unfortunate realities of politics.
When I think back to all the thousands of words I have written on positive feedback on this site, only to have it all said in two lines of a post at the same site:
On Positive Feedback
Name three positive feedback systems in nature. Get back to me on that when you’re done.
I might have said added “long-term stable” between name and three, but its pretty close.
Here goes. Three “natural” ones
The mistuned public address system. The hearing aid. The nuclear reactor. Very natural, all of them, as I think you’d agree.
Great! Now I can hear a mis-tuned public address system in my mind. It’s driving me crazy. What’s next, nails on a chalkboard?
I think that’s why our host wanted to add “long-term stable” to the quote, Bill.
A forest fire starts with ferocious positive feedback.
Bill,
None of the three you named are actually natural (occurring in nature). I’m not so sure you could say that any of them are really “long-term stable”, either.
Science fiction writer Larry Niven wrote a story years ago about what might happen to the first ship visiting Pluto. He imagined that all the hydrogen, oxygen, etc. would have frozen in layers and that when flames from the ship touched the gases they erupted in a fireball that circled the planet (or moonlet, or whatever it is now). That’s positive feedback!
The “positive feedback” issue is one that I don’t understand there being so much reluctance on. Personally, I feel it detracts a bit from the rest of your writings. I was actually disappointed by FR on this as well, and I’ve been in love with her writing since she was Equity Private.
Three relevant positive feedbacks off the top of my head: Algae blooms, invasive species, and Venus… which James Hansen himself proved.
I appreciate the insistence that positive feedbacks are a rare thing. But in many nonlinear systems, they occur regularly at transition points. I regularly read your blog, but please let up on the feedback intransigence.
I’ve predicted many times before that despite its basic flaws being pointed out to you repeatedly, you will never develop the necessary intelligence not to simply keep on parroting your bullshit about “long term stable”. You will also never develop the necessary intelligence to respond to any criticisms. The climate is not “long term stable”. Clearly you don’t understand the first thing about it if you think it is.
And why can’t you understand positive feedback? Your failure to do so is pathetic. For the benefit of anyone with slightly more brain cells than you possess:
Once again I’ll predict that you will be incapable of any meaningful response to this, and that you’ll trot out the same meaningless phrases within two weeks of now. Whenever I’ve predicted this before, I’ve been right.
Hunter,
I’m pretty sure Warren understands each of those. His counterpoint would be: Why did those things not cause runaway warming during warmer periods in the past? Whether during the MWP or previous epochs, those positive feedbacks were offset by negative ones at some point. Why now are positive feedbacks dominating?
Hunter,
If the climate is not “long-term stable”, then please explain how the climate has remained stable for the past 3 to 4 billion years (within a relatively narrow band of temperatures). By the way, I understand feedback, both positive and negative, as I have a BS in Electrical Engineering and Computer Science. If Earth’s climate was dominated by positive feedback, we would either be boiling or an ice cube by now, no other options are available.
Sean,
Actually, Venus is controlled by negative feedback as well. With an atmospheric pressure of about 90+ atmospheres and a distance only about 2/3 of Earth’s from the Sun, the temperature on Venus is at it’s stable temperature. Want to reduce the temperature on Venus? Introduce a sulfuric acid tolerant, carbon dioxide loving bacteria that can convert the carbon dioxide in the atmosphere into solid carbon. This would reduce the atmospheric pressure P (the equation relating pressure and temperature is PV=RT) which would reduce the temperature T as well since the volume V could be considered to be a constant and R is a constant based on the amount of gas present. R would probably change over time, but I’m not sure how much. It’s been too many years since I’ve taken Thermodynamics.
Bob,
For Venus: http://en.wikipedia.org/wiki/Atmosphere_of_Venus#Evolution
It’s a steady state now, yes, but of course everything reaches a steady state eventually. That’s not the concern. The concern is that for nonlinear systems short-term feedbacks can be positive and send it into a new state.
Think of a pendulum: swing the base of it at the natural frequency, in a direction opposite of pendulum. Negative feedback, and the pendulum stays largely at the bottom. Now do the same, but in the positive direction of the pendulum. Positive feedback (sortof), and the pendulum goes faster and faster until it is circling the base. It then enters a new steady state, circling the base. Now circling the base, it’s dominated by negative feedback keeping it in a certain phase-space. But so what: it’s no longer the same system we started with. The system (with pendulum and forcing aligned) was dominated by positive feedback for a short while. The climate could very well be like that: alternating between high- and low- energy states. If we happen to be pushing the phase of the swinging into alignment with the pendulum, it absolutely is positive feedback.
So the algae bloom example — we have a happy friendly pond environment that is overwhelmed by the algae. After the algae is there, it has other negative feedbacks keeping it in that state. But so what: all of our fish are dead.
* BP, the largest oil company in the UK and one of the largest in the world, has this opinion:
There is an increasing consensus that climate change is linked to the consumption of carbon based fuels and that action is required now to avoid further increases in carbon emissions as the global demand for energy increases.
* Shell Oil (yes, as in oil, the fossil fuel) says:
Shell shares the widespread concern that the emission of greenhouse gases from human activities is leading to changes in the global climate.
* Eighteen CEOs of Canada’s largest corporations had this to say in an open letter to the Prime Minister of Canada:
Our organizations accept that a strong response is required to the strengthening evidence in the scientific assessments of the Intergovernmental Panel on Climate Change (IPCC). We accept the IPCC consensus that climate change raises the risk of severe consequences for human health and security and the environment. We note that Canada is particularly vulnerable to the impacts of climate change.
Oh, what ignorance! How shamelessly you promote your own stupidity. How tragic.
“His counterpoint would be: Why did those things not cause runaway warming during warmer periods in the past?”
Would it be? Strange, isn’t it, how he seems completely incapable of arguing his own case. If that were his counterpoint, I would conclude once again that he’s an idiot who doesn’t understand the words he is saying. Who ever said anything about “runaway”?
“please explain how the climate has remained stable for the past 3 to 4 billion years”
It hasn’t. It has oscillated chaotically between palm trees at the poles and ice at the equator. Did you seriously not know that?
“By the way, I understand feedback, both positive and negative, as I have a BS in Electrical Engineering and Computer Science. If Earth’s climate was dominated by positive feedback, we would either be boiling or an ice cube by now, no other options are available.”
Clearly, you don’t understand feedback then. Here’s an equation that you could understand with even a very modest intellect, but that clearly you don’t:
ΔT = ΔF x f x S
ΔF is the change in outgoing radiation at the top of the atmosphere. f is the feedback factor. S is the climate sensitivity. ΔT is the temperature change that results. According to you, if f>0, ΔT = 0 or infinity and there are no other possible values. Your conclusion is stupid; this is because you haven’t understood the terms that you are dealing with.
The more I read hunted, the more I see cut-and-paste.
My only example of a “natural” positive feedback system is virulent, contagious disease (e.g. Spanish Flu of 1918). But even this, along with algae blooms and invasive species are limited. A disease will eventually burn itself out as the result of the hosts developing immunity or dying. Algae blooms are limited by substrate and environmental conditions. Rats are a good example of invasive species but even in this example other factors tend to keep them from completely taking over an ecosystem. It should be noted that all of these are biologic examples. How about some non-biologic examples in nature? Perhaps the forest fire started by lightening or an avalanche? These too are limited by natural processes.
Hi, just found your site and find it very interesting.
The arguments you put forward correspond to what I first thought when discussing global warming in the early 80’s – I was a micro-climate scientist and computer modeller at that time and the interest was just starting.
Your hind-casting argument on the choice of positive feedback model seems especially strong. This is exactly what I did in my models i.e. make sure that the model at least fitted the past. Of course that is no guarantee the model will fit the future – c.f. stock market trading models.
However I do think there are a number of positive feedback system that exist in nature that are only constrained by resources. For example:
– Immune response in auto-immune disease where the more your immune system responds, the more your immune system is provoked to respond.
– Geysers – quasi-stable systems driven by periodic bursts of positive feedback.
– Gravitational mass tends to increase with time and exponentially so
– Economies usually have exponential growth
– Climate change fanatics. The more there are, the more people want to join them
– Fire tolerance in plant species has progressed over a very long time from simply surviving a fire – survival of the fittest – to actively requiring fire to survive. As a result fire tolerant species take over entire regions and modify their environment so that fires are more common and deadlier (c.f. Australia Eucalypts) and so exclude less tolerant species. This process is continuing and has occurred over very long time periods.
– Host modifying parasites that change host behavior to ensure a wider spread – usually by a complex host to host cycle. This is distinct from ‘flu where there is no actual feedback other than proximity to the next host.