Talk:Tipping point (climatology)
|WikiProject Environment / Climate change|
This article misunderstands the meaning of tipping point, at least as its used by Hansen or Lenton. A tipping point is *not* when we get to a CO2 level that causes more CO2 to be emitted. Its something like when we get to a T change from CO2 that we are committed to melting Greenland. In fact the concept is very hard to define exactly (I would argue that no-one has done so: it remains a vague concept more useful for generating scary headlines than anythng else). See-also . Or  William M. Connolley (talk) 21:25, 9 April 2008 (UTC)
- Agree. Hansen seems to like the "small cap" warm weather sea ice removal temperature. Excerpt:
Early energy balance climate models revealed a “small ice
cap instability” at the pole (Budyko, 1969; North, 1984), which implied that, once sea ice retreated to a critical latitude, all remaining ice would be lost rapidly without additional forcing. This instability disappears in climate models with a seasonal cycle of radiation and realistic dynamical energy transports, but a vestige remains: the snow/ice albedo feedback makes sea ice cover in summer and fall sensitive to moderate increase of climate forcings. The Arctic was ice-free in the warm season during the Middle Pliocene when global temperature was only 2-3�C warmer than today (Crowley, 1996; Dowsett et al., 1996). Satellite data indicate a rapid decline, �9%/decade, in perennial Arctic sea ice since 1978 (Comiso, 2002), raising the question of whether the Arctic has reached a “tipping point” leading inevitably to loss of all warm season sea ice (Lindsay and Zhang, 2005). Indeed, some experts suggest that “. . . there seem to be few, if any, processes or feedbacks that are capable of altering the trajectory toward this ‘super interglacial’ state” free of summer sea ice (Overpeck et al., 2005).
- Well, someone claims to have defined it, and here's their definition . Here's the article it's an appendix to . I cross-posted this at Talk:Dynamical system, because I think the definition comes from the theory of dynamics and doesn't really have anything to make it a separate concept. But I would have to go through the math, whereas it should be trivial for an expert in dynamics to see whether the definition looks like a quote or looks like incompatible jargon from a different discipline. Dan Wylie-Sears 2 (talk) 07:19, 8 February 2009 (UTC)
- 1 Advocacy groups
- 2 Why isn't this linked to Category:Climate change, as tipping can go either way ... ?
- 3 addition tipping point "How it all ends" http://www.youtube.com/watch?v=mF_anaVcCXg ?
- 4 Kerr
- 5 a nice argumentative end
- 6 add related Cascade effect (ecology)
- 7 Self contradiction?
- 8 What is the Meridian Programme?
- 9 Definition might be improved by including mention of feedback
- 10 edits
- 11 Reversibility?
- 12 Ice sheet melt citation
- 13 Gail Whiteman report
- 14 No longer a "somewhat ill-defined concept" - this needs an update.
- 15 tipping points and tipping elements
I think it is appropriate to say somewhere on the page that advocacy groups have sprung up around the concept of a tipping point, and that a goal of 350ppm has been proposed and embraced by people like Hansen. There seems to be no cogent reason to exclude the fact that the concept of a tipping point has had a social response. 02:21, 22 September 2009 (UTC)
- Example  where an env. activism groups cites the "tipping point" as a call to arms. 04:45, 22 September 2009 (UTC)
- Hmm. Seems to me there's no good reason to include such information in this article. But I might be convinced if the editor(s) wanting to add it weren't spamming 350.org on all articles containing the number 350, and reasons why it's important were added here. — Arthur Rubin (talk) 18:17, 12 October 2009 (UTC)
- It's in Category:Climate crisis, which is a logical subcategory of Category:Climate change. It shouldn't be in both, absent overriding considerations, per WP:SUBCAT.
- At least, that's my interpretation of WP:SUBCAT. — Arthur Rubin (talk) 00:40, 22 October 2009 (UTC)
addition tipping point "How it all ends" http://www.youtube.com/watch?v=mF_anaVcCXg ?
- Youtube videos are rarely appropriate anywhere, and that only if claimed by a reliable source. — Arthur Rubin (talk) 23:08, 24 November 2009 (UTC)
a nice argumentative end
It has been a while since I read the U.N. Millenium report (2006). 'Global Warming' is only one of the critical stressors on the biosphere.
Yet, [biosphere] does not even suggest that the real thing might be at a 'tipping point' of disintegration. Is this because it can not be proven or calculated until it actually disintegrates? Is there perhaps another place on the web that better represents this critical issue for mankind?
Google search of biospheric tipping point yields: http://www.johncairns.net/Papers/Threats%20to%20the%20Biosphere.pdf —Preceding unsigned comment added by Kapler42 (talk • contribs) 18:01, 24 November 2010 (UTC)
- See Planetary boundaries 18.104.22.168 (talk) 17:36, 6 February 2011 (UTC)
|Off topic chatter|
|The following discussion has been closed. Please do not modify it.|
- It's more related to the general concept of "tipping point" than to this article. As a non-scientist, you should do better at constructing that article than I would be. — Arthur Rubin (talk) 03:27, 18 November 2011 (UTC)
The initial statement that a tipping point is the change form one stable state to another seems to be contradicted by a later point that it may be passed without any obvious consequences. If the two states are indistinguishable then in what sense are they distinct? I think some clarification of what exactly it is in the climate that has "tipped" is required. In the example of the Greenland icesheets explicitly stating the parameter of concern would help, is it the thickness, the temperature, the speed or something else? — Preceding unsigned comment added by 22.214.171.124 (talk) 12:11, 13 December 2011 (UTC)
- Good point. I think the intent is that the tipping point is not the change in the state, itself, but the change in a parameter which makes the change to another stable state inevitable. Some work on the general concept of "Tipping point" would be appreciated. — Arthur Rubin (talk) 01:11, 14 December 2011 (UTC)
What is the Meridian Programme?
Definition might be improved by including mention of feedback
Seems to me that feedback is the thing that makes the system tip and should be mentioned. In the wine glass analogy a small change (less than the tipping point) results in negative feedback which returns the system to the initial state, whereas a slightly larger change that passes the tipping point results in positive feedback that inevitably sends the system off into the new state. (this gels with Hansen's comments further down that we have already passed the tipping point for climate change == the climate sensitivity is positive)
In short I'm suggesting the definition of the tipping point is when the sign of the feedback changes from negative to positive. — Preceding unsigned comment added by 126.96.36.199 (talk) 05:33, 11 January 2012 (UTC)
Is passing a tipping point always irreversible? If it is always irreversible it should be beefed up to say so. If not then it isn't a defining feature and probably doesn't deserve to be mentioned in the intro. — Preceding unsigned comment added by 188.8.131.52 (talk) 12:49, 15 June 2012 (UTC)
- I thought it was more like a hysteresis point; not necessarily irreversible, but requiring a lot more effort to reverse. I could be wrong, though. — Arthur Rubin (talk) 14:37, 15 June 2012 (UTC)
Ice sheet melt citation
Is the sentence "At some level of temperature rise, the melt of the entire ice sheet will become inevitable, even though complete melting may not occur for millennia." meant to be an established fact or just a possible scenario? If it's a fact then a citation is warranted otherwise something to indicate it's a speculator such as changing "will" to "might" is needed. — Preceding unsigned comment added by 184.108.40.206 (talk) 10:28, 17 June 2012 (UTC)
Gail Whiteman report
This ref was removed: Gail Whiteman reporting that methane release can happen 'at any moment' Perhaps another article about the same report can be integrated KVDP (talk) 16:41, 6 November 2013 (UTC)
- But why. As your link says, academics argue that a significant release of methane from thawing permafrost in the Arctic could have dire implications for the world's economy and that is the point of the report. So it has nothing to add here. Its also rubbish, IMHO. But don't take my word for it William M. Connolley (talk) 19:37, 6 November 2013 (UTC)
No longer a "somewhat ill-defined concept" - this needs an update.
Elsewhere on the internet the casual researcher will find plenty of good text and graphical explanations of tipping points. Google text and images.
- I'm afraid this one is ill-defined; to be precise, the "good text and graphical explanations" of tipping points are not about the same concept. The general concept of "tipping point", for which we do not have an article, might be well-defined. — Arthur Rubin (talk) 01:45, 29 March 2014 (UTC)
tipping points and tipping elements
I fear the name of the article does not match its content. This article is about tipping elements, but it is titeled "tipping point". You can see this when you look at what Lenton et all really highlights in his cited publication: These are tipping elements, not tipping points. The tipping point exists, too: It is the point at which the tipping element flipps. --Hg6996 (talk) 19:06, 7 June 2014 (UTC)
- No, the article is about tipping points; it just happens that the only examples are from Lenton William M. Connolley (talk) 20:47, 7 June 2014 (UTC)
- Maybe the article is intended to write about tipping points and a part of it indeed does so but to do so consequently the section "examples" should also list tipping points.
- But instead it lists tipping elements but names them tipping points.
- If it would list tipping point the point at which the tipping elements flipp (or at which they are assumed to flipp) should be listed.
- I cite the abstract from the cited source, Lenton at all.
- He writes:
- "The term “tipping point” commonly refers to a critical threshold at which a tiny perturbation can qualitatively alter the state or development of a system. Here we introduce the term “tipping element” to describe large-scale components of the Earth system that may pass a tipping point". --Hg6996 (talk) 07:35, 8 June 2014 (UTC)