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] >> >> >> >> > > --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
