- This topic is empty.
March 29, 2012 at 6:12 pm #8573Raúl Ilargi MeijerKeymaster
G.G. Bain Wingmen October 1919 "Transcontinental air race, Roosevelt Field, New York. Col. A. Miller, Lt. E.C. Kiel, Sgt. F.K. McKee"
[See the full post at: The Nature of Tipping Points]March 29, 2012 at 11:46 pm #2171LivedeadcatParticipant
There is another kind of tipping point, which engineers call “phase change.”
In this situation, the load can be increased far beyond the point of equilibrium before it reaches a toggle point. An example of this might be the Greenland ice sheet, which can decay pretty far without substantial movement. Then, suddenly and without warning, the whole thing goes, something everyone thought should have happened much earlier. Or, using the straw-loading example, the calculated toggle point might be far exceeded before the camel’s knees actually give out.
A sense of complacency might be a likely result when expected overloads do not result in collapse.March 30, 2012 at 6:21 am #2175Mark TMember
“We are about to find out that economics and finance has a far bigger impact on your life than politics, and if you don’t believe me let me finish with a very clear declaration, and hold me to this, come back at me years in the future.
The sovereign debt problems along with the costs of an aging population are going to revamp society in the most profound way, and the part that worries me, that includes violent social unrest, and those who don’t understand it are just going to be road kill along the way.”
Michael Campbell (the brother of former B.C. Premier Gordon Campbell) made the above statement on his “Money Talks” radio show last Saturday on radio station CKNW in Vancouver, B.C.
If anyone wishes to listen to these words for themselves click on the following link to CKNW’s audio vault enter March 24 in the date drop down box, 8:00 AM in the time drop down box and then click on “listen”. When the audio starts to play, move the slider ahead to 39 minutes and 30 seconds to hear the quote. (Put your mouse on the bar just above the “listen” tab, click the mouse, hold it down and then slide the pointer ahead on the bar. You have to release the mouse to see where you are, and then repeat the process again one or two times to get to the 39 minutes and 30 seconds mark.) You do not have to register on the website to use the audio vault. It is strictly click and play. CKNW’s audio vault stores program audio for a period of 30 days.March 31, 2012 at 7:37 pm #2193pipefitParticipant
Good article. However, I disagree on how to define a tipping point. In the case of a camel, it might very well be a specific straw that, when added, causes the legs to buckle. In the case of climate change or human population, I think we can have less well defined tipping points.
Once 99% of the water that can be easily routed into irrigation canals has been diverted, then a tipping point has probably been reached. From that point forward, average human calorie consumption will decline in direct proportion to population increase, with an adjustment for genetic improvements.
In the case of climate change, once the permafrost melts, releasing a whole new source of methane, that is probably a tipping point, even if the associated warming doesn’t happen for a decade or more later.
In the case of the financial markets, there is too much manipulation to sort it out. You would have thought that a tipping point would have been reached long ago, with federal spending, on a GAAP basis, at 40% of GDP.April 2, 2012 at 6:49 am #2237bmcmMember
Nice article on the “tipping point” concept; but it doesn’t explicitly mention what I think is the most decisive aspect – irreversibility. That is, once you cross a tipping point not only do you get a relatively “large” change in the “output” variable of interest (possibly after a lag in time, which may be long), but simply reversing the input variable back below the tipping point cannot fix this. In this sense, although “tipping point” conjures up the image of a balance scales (or see-saw), that is completely the wrong idea: because with a scales, just adjusting the relative weights back will tip the balance back the other way. That doesn’t work with real “tipping points” – or at least, not the kind of concern in climate change.
The distinction is clearly seen in the metaphor of the camel’s back: removing that last straw can’t make the camel whole again. Now mind you, sometimes irreversibility is more limited that that: it may be possible to get back to where you were, but simply bringing the input back below the original (“upward”) tipping point will not suffice. Instead, it is necessary to bring the input back below some lower value – the “downward tipping point”. This is called hysteresis. One of the simplest and most familiar example of a system with hysteresis is the typical light switch: once you push past the “tipping point” for “on”, it clicks or locks into that state and you then have to push a good bit in the opposite direction to get back to the “off” state. Hysteresis is typical of systems involving positive feedback – like the climate system.
So in the context, it might be better not to talk about “tipping points”, but rather “points of no (practical) return”. In even a moderately complex system it is typically hard to be sure when such a point is crossed; but in the case of the current situation with climate, I would not be optimistic…
Regards – Barry.
- You must be logged in to reply to this topic.