Not sure how dispersed ship traffic is, in fact. This site has some interesting data visualization for shipping patterns. http://sappingattention.blogspot.com/2014/03/shipping-maps-and-how-states-see.html
From: [email protected] [mailto:[email protected]] On Behalf Of Mike MacCracken Sent: Thursday, August 14, 2014 12:23 PM To: Andrew Lockley; Geoengineering Subject: Re: [geo] On the effects of bunker fuel desulfurization Sorry, Andrew, not the type of careful analysis that is needed. Polluted air blows off the continents and so doing cloud brightening would not work in those air masses, etc., which is why, as Stephen indicates, they want to avoid those areas, etc. Much of the NH mid-latitudes, for example, may have too much pollution all across the oceans for cloud brightening to work-so what will happen when those polluted regions become less polluted-will clouds appear or disappear, brighten or not? That is the question. Best, Mike On 8/14/14 11:59 AM, "Andrew Lockley" <[email protected]> wrote: Ship traffic terminates in busy ports, but on the high seas, they are relatively dispersed, and cross winds serve to distribute the sulphur and / or resulting aerosols. I remain of the opinion that making this change without good science is an extremely risky thing to do. A On 14 Aug 2014 16:43, "Mike MacCracken" <[email protected]> wrote: I was asked by a colleague about what is expected to happen as marine bunker fuels are desulfurized over the coming several years. My first response was that it would reduce the SO2 emissions and so the sulfate, and since sulfate adds to cooling, this would suggest the desulfurization would lead to a warming influence. But then, the key to cloud brightening is addition of CCN in relatively unpolluted regions (so yes, over remote oceans), but is not much of the ship traffic in relatively polluted regions? Experiments do seem to indicate that over-saturation of CCN tends to lead to cloud clearing--so basically we are in the Goldilocks situation--one needs to have neither too few CCN nor too many to get cloud brightening. So, might it be that in some polluted regions, reducing the SO2 emissions from marine sources might actually lead to an increase in clouds/cloud brightness? Has anyone done a really careful analysis of this? Do we really have good quantitative estimates of what might happen? And how might all of this play out as the other sources of SO2 are changing? Perhaps Stephen Salter, John Latham, Alan Gadian, et al. have a paper(s) on this that I have missed. Mike MacCracken -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected] <mailto:geoengineering%[email protected]> . To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]<mailto:[email protected]>. To post to this group, send email to [email protected]<mailto:[email protected]>. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
