Increased column stability may affect hydrological cycle and thus thermohaline circulation.
This could be problematic and modelling seems wise A On Nov 3, 2011 4:15 PM, "O Morton" <omeconom...@gmail.com> wrote: > Stephen (or John, or Phil, or anyone else) have any of your modellings > of cloud brightening looked at this effect? If you were to brighten > clouds under a dark aerosol (eg Asian Brown Cloud or equivalent off > west africa) might you not be trading warming at the surface for > warming at the dark aerosol layer above the cloud, and thus a) getting > less of an effect in terms of overall cooling and b) contributing to > an increased stability in the amtopsheric column that would suppress > convection (thus perhaps having an effect on the clouds themselves?) > Doesn't seem obvious how this would net out -- if warming the > atmosphere above made the clouds more stable i suppose this might > increase the cooling for a given seeding. Is it something you've > looked at? > > On Oct 28, 5:37 pm, David Keith <david_ke...@harvard.edu> wrote: > > Greg et al > > > > There are a number of reasons why white roofs might cause heating that > are well explained in the paper. Among them local suppression of convection > and the correlation between where the roofs are and absorbing dust > particles. The roofs we plan to whiten tend to be in places with dirty air, > and so the problem of absorption is much more pronounced than if we > scattered the whitening randomly over the planet. > > > > Your analogy to large-scale albedo changes is false because both the > interaction with convection and the correlation with dirty air are not > present in that case. > > > > I think it will take more papers to really nail this down but there's > nothing impossible about this result and at a glance the paper seems > sensible and serious. > > > > > Http://www.stanford.edu/group/efmh/jacobson/Articles/Others/HeatIsland+White. > .. > > > > David > > > > > > > > > > > > > > > > -----Original Message----- > > From: geoengineering@googlegroups.com [mailto: > geoengineering@googlegroups.com] On Behalf Of Rau, Greg > > Sent: Friday, October 28, 2011 10:40 AM > > To: s.sal...@ed.ac.uk; geoengineering@googlegroups.com > > Subject: RE: [geo] White roof snag > > > > ""A worldwide conversion to white roofs," they found, could actually > warm the Earth slightly due a complex domino effect. Although white > surfaces are cooler, the increased sunlight they reflect back into the > atmosphere by can increase absorption of light by dark pollutants such as > black carbon, which increases heating. " > > > > So by analogy, increased snow/ice cover would "actually warm the Earth > slightly" ? I don't think so, but please clue me in. - Greg > > > > ________________________________________ > > From: geoengineering@googlegroups.com [geoengineering@googlegroups.com] > On Behalf Of Stephen Salter [s.sal...@ed.ac.uk] > > Sent: Friday, October 28, 2011 4:22 AM > > To: geoengineering@googlegroups.com > > Subject: [geo] White roof snag > > > > Hi All > > > > See > > > > http://www.guardian.co.uk/environment/2011/oct/27/white-roofs-global-... > > > > and > > > > Jacobson, M., & Ten Hoeve, J. (2011). Effects of Urban Surfaces and > White Roofs on Global and Regional Climate. Journal of Climate DOI: > 10.1175/JCLI-D-11-00032.1<http://dx.doi.org/10.1175/JCLI-D-11-00032.1> > > > > Stephen > > > > Emeritus Professor of Engineering Design Institute for Energy Systems > School of Engineering Mayfield Road University of Edinburgh EH9 3JL > Scotland Tel +44 131 650 5704 Mobile 07795 203 195www.see.ed.ac.uk/~shs< > http://www.see.ed.ac.uk/~shs> > > > > -- > > You received this message because you are subscribed to the Google > Groups "geoengineering" group. > > To post to this group, send email to geoengineering@googlegroups.com. > > To unsubscribe from this group, send email to > geoengineering+unsubscr...@googlegroups.com. > > For more options, visit this group athttp:// > groups.google.com/group/geoengineering?hl=en. > > -- > You received this message because you are subscribed to the Google Groups > "geoengineering" group. > To post to this group, send email to geoengineering@googlegroups.com. > To unsubscribe from this group, send email to > geoengineering+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/geoengineering?hl=en. > > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
