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 -~----------~----~----~----~------~----~------~--~---
