I have been unable to find any citations in 'hard' climate science literature. Is the term therefore ONLY a pop-science concept?
If anyone has any such citations, please can they send them to me? A 2009/2/2 David Schnare <[email protected]>: > The concept, as applied to climate change, was introduced to discuss loss of > ice shelves, an "irreversible" event over the short run, and one with large > consequences. Then, the concept was expanded to the speed of the event, > also as applied to the ice shelves. Then it was expanded to the "fat tail" > possibility of very high temperatures. > > In each case, the presumption (presumption, not reality mind you) was that > the event was unstoppable once started, much like an explosion. The > inability to "quench" an event should not be confused with the ability to > restore (more or less) the initial conditions, or otherwise reach a (new or > modified) equilibrium. > > "Runaway" is a loaded term. We've had a dust up over use of such terms in > the recent past. As far as I can tell, at this point, environmental > activists are allowed to use them, government employees are not, scientists > should not, and wiki authors - god knows! > > Cheers, > d. > > On Mon, Feb 2, 2009 at 6:33 AM, Eugene I. Gordon <[email protected]> > wrote: >> >> I guess it is not going to end. >> >> A runaway train meets only #2 and even that has to be qualified because >> the >> train eventually runs out of (fossil?) fuel or track. Certainly climate >> has >> run away a half dozen times in 540 million years but always hits a limit >> which seems to be 24C except when an asteroid hits. It eventually turns >> around after remaining at the limit temperature for many millions of >> years. >> We have been in a runaway mode for the last 18,000 years but with some >> superimposed small wiggles in temperature. Without geoengineering the >> temperature will certainly get to the 24 C limit. >> >> I think runaway is appropriate for the current situation even if there may >> be better suited terms. >> >> -----Original Message----- >> From: [email protected] >> [mailto:[email protected]] On Behalf Of John Nissen >> Sent: Monday, February 02, 2009 6:08 AM >> To: Tom Wigley; Andrew Lockley >> Cc: geoengineering; Prof John Shepherd; Tim Lenton; David Lawrence >> Subject: [geo] Re: runaway climate change >> >> >> >> Dear Tom, >> >> The concept of "runaway" has certain connotations: >> >> 1. Significant in resultant effect >> 2. Uncontrollable >> 3. Exponential initial behaviour - characteristised by acceleration of >> process 4. No obvious limit 5. Irreversible 6. Rapid. >> >> These can all be applied to climate change: >> >> 1. "Significant" could be over 5 degrees global warming, sufficient for a >> mass extinction event. Or it could be applied to several metres of sea >> level rise. >> 2. "Uncontrollable" could be where anthropogenic greenhouse gas emissions >> reduction would not have a significant effect on the rate of climate >> change. >> 3. Exponential behaviour could be caused by a "tipping" of some part of >> the >> climate system, such as Arctic sea ice or methane release, where there is >> strong positive feedback. >> 4. There would be no obvious final equilibrium temperature - mainly >> because >> of the difficulty of modelling positive feedback and its behaviour over >> time. >> 5. It would be extremely difficult or impossible to reverse processes >> such >> as methane release or Greenland ice sheet disintegration, although it is >> conceivable to halt these processes or even reverse their effects >> (presumably through geoengineering). >> 6. "Rapid" could be anything from one season to 3000 years, on a >> geological >> timescale. >> >> Therefore I think that "runaway" captures the semantics that we require >> for >> the climate change that would result from, for example, a massive methane >> release, triggered by Arctic sea ice disappearance. Can you think of a >> better word to capture the six characteristics above, especially as >> applicable to climate change? >> >> Cheers, >> >> John >> >> >> >> ----- Original Message ----- >> From: "Tom Wigley" <[email protected]> >> To: "Andrew Lockley" <[email protected]> >> Cc: <[email protected]>; "geoengineering" >> <[email protected]>; "Prof John Shepherd" >> <[email protected]>; "Tim Lenton" <[email protected]>; "David Lawrence" >> <[email protected]> >> Sent: Monday, February 02, 2009 3:43 AM >> Subject: Re: [geo] Re: runaway climate change >> >> >> > Andrew, >> > >> > Poor analogy. running does not equal running away. >> > >> > More importantly, just because a term has been misused in the >> > past does not mean we should perpetuate its misuse (or use). >> > If the word is to be used at all (and, as a practicing scientist, >> > I never have or will), one should start off by saying that the >> > word runaway is open to misinterpretation, that it does not >> > mean running off to infinity, and that it's real meaning is ... >> > etc. etc. Then talk about irreversible changes (with the caveat >> > that even these are probably not irreversible), positive >> > feedbacks (which also have limits), etc. >> > >> > Tom. >> > >> > +++++++++++++++++++++++==== >> > >> > Andrew Lockley wrote: >> >> For better or worse, the term is now in general use in scientific, >> >> industrial, environmental and general media. (See >> >> http://en.wikipedia.org/wiki/Runaway_climate_change for refs.) >> >> >> >> I don't agree with Tom about 'to infinity and beyond'. I run as a >> >> hobby, and I've never run to infinity (or beyond). I think most >> >> people realise that runaway doesn't mean run-for-ever. >> >> >> >> However, a general definition would be very useful. >> >> >> >> A >> >> >> >> 2009/2/2 <[email protected]>: >> >>> Dear All, >> >>> >> >>> I've said this before, but here goes again. >> >>> >> >>> If one sticks to dictionary definitions of words (which I >> >>> think is wise) then there is no such thing as "runaway" >> >>> climate change. Strictly, using the words of Buzz Lightyear, >> >>> "runaway" must mean "to infinity and beyond". >> >>> >> >>> Further, the word "runaway" is loaded and should be eschewed >> >>> in the climate context. >> >>> >> >>> The confusion here is that what some people are calling >> >>> "runaway" climate change is really better referred to as >> >>> "irreversible" climate change. For instance, the sudden release >> >>> of a large amount of CH4 would possibly cause large warming >> >>> that would put the globe in a new state that was much warmer >> >>> than present. But the climate (or global-mean temperature) would >> >>> *not* runaway -- it would eventually stabilize. Even this change >> >>> would not strictly be irreversible, as the excess CH4 would >> >>> slowly be oxidized (more slowly than today because of the well >> >>> known positive feedback of CH4 on its own lifetime due to OH loss), >> >>> but a lot of the excess CH4 would slowly disappear and be replaced >> >>> by CO2 that has less forcing. This CO2 would, of course, stay >> >>> around for a long time. >> >>> >> >>> If anyone is interested, this case can easily be run with MAGICC, >> >>> but some minor tweaks are needed to get the CH4 to CO2 flux right. >> >>> Conceptually trivial. >> >>> >> >>> So, please, please try not to cry wolf with these loaded and sadly >> >>> oft-misused words. >> >>> >> >>> Tom. >> >>> >> >>> ++++++++++++++++++++++++++++ >> >>> >> >>>> >> >>>> Andrew, >> >>>> >> >>>> 1. I think the concept of runaway climate change is kosher. See >> >>>> this >> >>>> quote >> >>>> from >> >>>> http://www.meridian.org.uk/_PDFs/FeedbackDynamics.pdf >> >>>> >> >>>> "The possibility of a tipping point in the earth system as a whole >> >>>> which >> >>>> prevents the recovery of stable equilibrium and leads to a process of >> >>>> runaway climate change, is now the critical research agenday, >> >>>> requiring >> >>>> the >> >>>> concerntration of global resources in a "Manhattan Project" style >> >>>> engagement. All other work on impact assessment, mitigation and >> >>>> adaptration >> >>>> depends on the outcome of thie overarching issue" >> >>>> >> >>>> I would prefer to have "runaway global warming", because that's what >> >>>> we >> >>>> are >> >>>> really talking about, but "climate change" is almost interchangeable >> >>>> with >> >>>> "global warming" these days. >> >>>> >> >>>> 2. The domino effect is mentioned here: >> >>>> http://researchpages.net/ESMG/people/tim-lenton/tipping-points/ >> >>>> >> >>>> The release of methane is likely to be triggered by the loss of >> >>>> Arctic >> >>>> sea >> >>>> ice, according to David Lawrence: >> >>>> http://www.ucar.edu/news/releases/2008/permafrost.jsp >> >>>> >> >>>> 3. I believe it is generally accepted that the Arctic sea ice albedo >> >>>> effect >> >>>> contributes to the accelerated warming trend in the Arctic region. >> >>>> It >> >>>> is >> >>>> also accepted that this effect presents a strong positive feedback on >> >>>> the >> >>>> local warming, but currently presents only a weak positive feedback >> >>>> on >> >>>> global warming. Thus if the local warming can be halted, and methane >> >>>> release domino effect thereby avoided, then we can avoid passing a >> >>>> point >> >>>> of >> >>>> no return, or going "over the waterfall" as you put it. >> >>>> >> >>>> I'd be interested to know if Prof John Shepherd agrees with this >> >>>> assessment. >> >>>> >> >>>> 4. Additional point - only albedo (shortwave radiation) >> >>>> geoengineering >> >>>> has >> >>>> any chance to halt the local warming in the Arctic. >> >>>> >> >>>> Again I'd be interested to know whether Prof Shepherd agrees with >> >>>> this. >> >>>> >> >>>> Cheers, >> >>>> >> >>>> John >> >>>> >> >>>> >> >>>> ----- Original Message ----- >> >>>> From: "Andrew Lockley" <[email protected]> >> >>>> To: "geoengineering" <[email protected]> >> >>>> Sent: Sunday, February 01, 2009 12:33 PM >> >>>> Subject: [geo] runaway climate change >> >>>> >> >>>> >> >>>> I'm working on http://en.wikipedia.org/wiki/Runaway_climate_change >> >>>> >> >>>> and there are a few crucial questions I could do with help on: >> >>>> >> >>>> 1) Is the term 'Runaway climate change' seen as kosher, or is it >> >>>> purely a pop-science concept? >> >>>> 2) How widespread is support for the idea of an ice-albedo followed >> >>>> by >> >>>> a clathrate/permafrost domino effect? Is it speculative or accepted? >> >>>> 3) Is there consensus on 2) above as regards timing? All the sound >> >>>> evidence I've read says we've already fallen over the waterfall. Do >> >>>> others agree? >> >>>> >> >>>> If you have any general thoughts on the matter, or notable people and >> >>>> sources you'd care to inform me of, then please email back >> >>>> [snip] >> >>>> >> >>>> >> >>>> >>>> >> >>> >> > >> > >> > >> >> >> >> >> >> > > > > -- > David W. Schnare > Center for Environmental Stewardship > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en -~----------~----~----~----~------~----~------~--~---
