Just to note that coal-fired emissions of SO2 are in the range of several tens of millions of tons per year, so something like four orders of magnitude greater than has come out of the volcano.
And if the sulfur output is 3-4 kt and the volcano has been putting out roughly 750 tons/second for near a week, total emissions of ash are something like 100,000 times the sulfur output. If I have done the calculations right, the global emissions right now are the equivalent to 1/1000 the rate of the volcanic eruption as pure sulfur extending over a year. And injection to the stratosphere would likely need to be less than 1/10 of that rate. And having a sea ice-restoring effect in the Arctic would likely be that or less. What we are seeing is about 99.999% ash--so not really anything like an analog of geoengineering with sulfate. The question instead should be if it might have a warming influence due to the dark ash and that it will discolor the surface for longer than its atmospheric lifetime, but over a lesser area. Mike MacCracken On 4/19/10 5:21 PM, "Jim Fleming" <[email protected]> wrote: > Thanks for the images. It better not be an analog, however, since > geoengineers never proposed tropospheric aerosol injections and would not > want to mess up aviation. > > Last week Alan Robock reported only 3-4 kt (0.003-0.004 Mt) of SO2 from the > Eyjafjallajökull volcanic eruption in Iceland as compared to 5 Mt from > Katmai in 1912 and 20 Mt from Pinatubo. Furthermore, it only went into the > troposphere, with a lifetime of a week or so. So he expects "absolutely no > climatic effect based on emissions so far." In other words, a much larger > injection for a period of years (essentially a geoengineering implementation > scenario) would be needed to detect a climate response. > > > > On 4/19/10 3:58 PM, "Ning Zeng" <[email protected]> wrote: > >> All: Below is a link to a series of MODIS images of the Iceland >> volcanic eruption beginning in March. Depending on how it goes, it >> could be a natural analog to targeted Arctic geoengineering. -Ning >> Zeng >> >> http://earthobservatory.nasa.gov/NaturalHazards/event.php?id=43253 > -- 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.
