Andrew No one cares what the wiki people like.
David Schnare Center for Environmental Stewardship On Feb 2, 2009, at 6:50 PM, Andrew Lockley <[email protected]> wrote: > > I have an alternative theory as to why we don't see too many instances > of runaway climate change from the 'clathrate gun' effect, or from > permafrost. > > Methane has a very short life in the atmosphere, but is a potent > greenhouse gas. If the rate of warming is low, a little methane is > released, which quickly degrades to CO2 which has little short term > effect and can then disappear into sinks. As warming continues, more > methane is released, but never fast enough to make a significant > difference to the climate before it degrades again to CO2. > > HOWEVER: > > In AGW, the temperature is rising very fast. This has the potential > to make methane belch out from soils and seas very quickly. This > speed is of the essence, as large quantities of methane will be enough > to influence future methane release to create a runaway event. > > The process is like pull starting a chainsaw. A little tug gets you > the odd cough. Tug hard, the the chainsaw motor gets started and runs > on its own. > > Now, pretty please with sugar on top, can someone tell me what the > proper, scientific, not-to-be-argued with name for that process is? > The people on wikipedia really don't like 'runaway climate change' - > as apparently 'proper' climate scientists don't use that term. > Citations much appreciated, thankyou!! > > A > > 2009/2/2 Alvia Gaskill <[email protected]>: >> Not enough CO2 in the atmosphere. >> >> ----- Original Message ----- >> From: Andrew Revkin >> To: [email protected] ; [email protected] >> Cc: [email protected] ; Tom Wigley ; Andrew Lockley ; >> geoengineering ; >> Prof John Shepherd ; Tim Lenton ; David Lawrence >> Sent: Monday, February 02, 2009 3:29 PM >> Subject: [geo] runaway climate change >> Who on this list knows why the Arctic warming ~ 8,000 years ago >> (quite >> protracted and significantly warmer than today) did not lead to >> "runaway" >> warming? >> Presumably something kicked in the other direction? >> I'm pursuing a clearer picture of lessons from the Holocene and the >> Eemian >> (the previous interglacial) related to feedbacks and whether there >> are, or >> are not, one-way doors in the climate system. Leads eagerly >> pursued. .. >> Andy >> At 5:29 PM +0530 2/2/09, Govindasamy bala wrote: >> >> Runaway feedback means running its course completely. It is feedback >> specific. >> >> A good example is the presumed water vapor feedback on Venus. >> Apparently, earth and venus started with similar amount of h2o. >> Because Venus started with much higher surface temperature, the >> evolution of >> temperature and water vapor never intercepted the phase line of >> vapor and >> liquid. The climate warmed until all the water got evaporated. >> Basically, >> there was no sink for vapor which precipitation. On earth, this is >> not going >> to happen because we got the precipitation sink on earth...how >> lucky we are. >> >> But I guess we do have runaway ice-albedo feedback on earth. we >> could get >> ice-free planet or snowball earth........ >> >> Cheers. >> Bala >> >> On Mon, Feb 2, 2009 at 5:03 PM, 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] >>>>>> >>>>>> >>>>>>>>>> >>>>> >>> >>> >>> >> >> >> >> >> >> >> -- >> Best wishes, >> >> ------------------------------------------------------------------- >> Dr. G. Bala >> Associate Professor >> Center for Atmospheric and Oceanic Sciences >> Indian Institute of Science >> Bangalore - 560 012 >> India >> >> Tel: +91 80 2293 2698 >> +91 80 2293 2505 x206 >> +91 9741991621 (cell) >> Fax: +91 80 2360 0865 >> Email: [email protected] >> [email protected] >> Web:http://caos.iisc.ernet.in/faculty/gbala/gbala.html >> ------------------------------------------------------------------- >> >> >> >> -- >> >> Andrew C. Revkin >> The New York Times / Environment >> 620 Eighth Ave., NY, NY 10018 >> Tel: 212-556-7326 Mob: 914-441-5556 >> Fax: 509-357-0965 >> http://www.nytimes.com/revkin >>> >> > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "geoengineering" group. 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