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EnviroLink Forum • View topic - Tipping points approaching?

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PostPosted: Tue Jun 12, 2012 9:54 am 
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PostPosted: Wed Jun 13, 2012 5:53 am 
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No.

What is going to suddenly change?

What mechanisim will it be that alters?

Plants rot and give off CO2 and methane etc as allways. What point will need to be achieved to get a positive feed back loop?

What temperature rise will we have to see for this catastrophy to happen?

What mechanisim will do this tipping? Why will it do it at this time?

The IPCC says that the worst case scenario is for a 6.4 degree c temperature rise by 2100 but this, I think, has been revised down to a more reasonable max of 3.2 degrees. That would give an expected foot or so of sea level rise. Do you have information that the IPCC has it wrong? They don't talk of a tipping point resulting in positive feedback.


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PostPosted: Wed Jun 13, 2012 7:32 am 
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PostPosted: Wed Jun 13, 2012 7:36 am 
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PostPosted: Wed Jun 13, 2012 7:42 am 
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http://www.livescience.com/8599-extinct ... table.html

When ecologists model the decline of species (a computer simulation of sorts), they see tipping points — sets of circumstances that make extinction all but certain.

To date, mathematical modeling has revealed a few statistical harbingers of tipping points. Right before a system reaches the point of no return, it goes through a phase called "critical slowing down." That phase is the statistical equivalent of the gut feeling you may experience right before a canoe tips over or a rollercoaster makes a plunge: that the system can no longer recover from perturbations in the environment (like your last-minute attempt to balance the canoe), and a dramatic change is imminent.

In nature, those perturbations might be small changes in temperature or precipitation, or simple normal fluctuations in how many offspring a species produces.

"The ability of the system to respond to perturbations, to these little nudges, is diminished," study researcher John Drake, an ecologist at the University of Georgia, told LiveScience. "So lots of little nudges accumulate, and that's what we call critical slowing down."

To find out if critical slowing down can predict extinction in real-world ecosystems, Drake and Blaine Griffen of the University of South Carolina used millimeters-long crustaceans called water fleas. The tiny algae-eaters were split into two groups and fed until their population stabilized. After about 150 days, the researchers stopped feeding one of the groups.

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PostPosted: Wed Jun 13, 2012 8:31 am 
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I should explain "positive feedback loop". When I took "industrial instrumentation technology" we would design control systems for various industrial processes. An example everyone knows about is the float control in a toilet tank. As you add water, the float rises up and operates a valve to slow down the water and eventually stop it. When you flush, the level goes down and the float drops and the valve is turned on again to fill the tank. The level of water is called the process. The float and the valve is called the feedback loop. When the level decreases, the water flow increases which is the opposite or a "negative" reaction. And vice versa, increased level results in decreased flow, the opposite reaction. If the valve was turned upside down so lifting the float increased the water flow, the tank would overflow because the float would be trying to add more water as the level rose... a positive feedback. Similarly, if you flush, the float would fall and decrease the water from decreased level... two negatives equals a positive so yeah it is a positive feedback and the tank will just run dry. As you can see, a positive feedback loop will cause the process to go to extremes but a negative feedback loop will control the process to reach a steady state.


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PostPosted: Wed Jun 13, 2012 9:28 am 
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I never imagined anybody was considering the equilibrium of new species formed to species going extinct. The extinction rate is very fast so to stop the decline in species numbers, we all have to believe in Creationism to make new species faster then the millions of years evolution requires. As for a positive feedback on extinction, I think you have to look at rats. Norway rats have caused the extinction of many species of rodents. People were not noticing because rodents are pests. Many small predators also became extinct before being cataloged because they could not kill and eat rats and the smaller rodents they relied upon were killed off by those rats. Then we started poisoning rats and ground squirrels and to our surprise, we lost countless insects, amphibians, and reptiles that inhabit the holes they live in. We narrowly saved the Black Footed Ferret but the black plague is killing them and their prey... another burrowing rodent. Many birds are now extinct or almost so because they relied on holes of animals or prey species that went extinct. A new poison for grasshoppers was introduced that stayed in the plants. Drastic reductions in rodent numbers resulted and surprise, surprise... birds of prey declined rapidly due to not having enough food to produce eggs (this included grasshopper-eating birds). Thankfully that pesticide has been banned in most countries but it was too late to stop the decline in some species... they are now declining due to inbreeding due to low numbers. This is only prairie rodents I am talking about... I think tipping points have past for many ecosystems already. Another factor is "bush meat" in many poor countries... as the easy-to-catch species get eaten, the endangered species become the next menu item. We need to stop farmers from growing cotton to growing grains and animals to keep food prices down to save wildlife... not going to happen. The tipping point is long past on that issue in many parts of the world. By the way, the easy-to-catch species I was referring to are the various rodents who (surprise) have largely become extinct due to poisoning efforts by farmers... a tipping point long since past.


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PostPosted: Thu Jun 14, 2012 8:38 am 
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So all these tippiing points are unknown airy predictions with no actual modeling or physics involved.

Might as well say anything. We are all doomed because of the great tipping pointed monster which will steal our souls....


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PostPosted: Thu Jun 14, 2012 9:05 am 
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PostPosted: Thu Jun 14, 2012 10:04 am 
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PostPosted: Thu Jun 14, 2012 11:09 am 
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I see this as very similar to the cigarette causing cancer debate for more than the reasons the same fallacies are used to confuse people.

The question could be posed about how many cigarettes will cause lung cancer. It seems on the surface to be a simple question and it is a very simple question that relies on a lot of very complex variables to give an answer. The fact is there may be a cancer rleated to smoking in a very short time frame or a very long time frame even with the same number of cigarettes consumed in a day. The other variables come into play in the final determination of when the effect will be exhibited. A probability range can be worked out based on larger numbers of people used as data points, but no definite determination can be made for a specific person to predict which cigarette will be the tipping point into cancer. We do not have a large number of planets to use as data points so we cannot create a similar probability range. Even if we did, the key is the one planet on which we live that may be one of the really early cases and if so we have passed a tipping point before we expect it and we are in trouble.

The only real solution to be safe is to assume there is no time to waste in mitigation as if this is the case and we wait we may not have the chance to attempt mitigation in the future.

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PostPosted: Mon Jun 22, 2015 1:15 pm 
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Passed the tipping point of runaway open ocean Arctic warming in 2007, and this year it is exponential. Most likely leading to the tundra methane tipping point completion of the positive feedback loop, well before 2030. The self release of hydrates from first shallow then deeper and deeper depths of the oceans, mid century and on. The human survivors die with most other surface species, with the rest taking longer.

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PostPosted: Tue Aug 25, 2015 1:29 am 
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2015 is hotter than 2014, enough to break that record. More blowholes, extreme record acreage of forest fires in the northern latitudes, & more days of higher methane.
Can humanity stop it ?
The logistics of rapid decarbonisation is getting worse, while the odds fall below 50% by 2024, or sooner. With so much denial still going on and overpopulation nearing the massive economic depression point, it is unlikely humanity will stop what the once stoppable overpopulation has wrought, with greed. General stupidity/ignorance, along with increased lack of foresight have brought us to the point of starting the open ocean warming to runaway. Historical, geologically, evidence indicates tundra methane self release over +1.5*C and well below 2*C, to initiate methane turnover. This is from PETM, with its very long recovery time, and it wasn't even a true ELE with a 30% extinction.
This is similar in some ways and not in others, to what has been measured so far. Such as now being an increase in CO2 40 times PETM, and a heat rise (before tundra methane self release) 10 times PETM. In addition to double the ocean acidification in the geologic record, something even the Permian Great Dying did not have, with its methane turnover resulting in a 95% extinction.
I know there is at least 10% more sequestered methane hydrate than PETM and at least 20% more than the Permian. The turnover in each other case, stopped at a percentage of methane release below 100%, or the deep ocean deposits. Permian 70% and PETM 50%, in my estimation. A 10*C and 8*C temperature rise. It is possible that clouds blocked further deep ocean warming, with axis and orbital influences.
If it goes to 100% methane release, followed by CO2 from baked earth, then it is the Venus Effect. Otherwise, if it stops at a similar to Permian Extinction with more loss from acidification, it could be a 30 million plus year recovery from a greater than 95% extinction. That is actually the best case scenario, unless there is Divine Intervention. :shock: :clap: :clap: :clap: :clap: [-o< [-o< [-o< [-o< [-o< :mrgreen:

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PostPosted: Tue Aug 25, 2015 3:23 am 
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Humans may not wait for 30 million years to recover our planet. Every year we experience different level of heat. If heat continue to increase each year, there is possibility that human population will decrease.


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PostPosted: Tue Aug 25, 2015 8:13 am 
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