But most engineering processes have efficiencies less than 90%, so if the coal and tars are burnt and the tundra carbon is released, say as CO2, and geoengineering removes 90% back to permanent sequestration, that leaves 10% of a very large number. We can expect substantially higher CO2 in the next few millennia, than was the case in past few.
= Stuart = Stuart E. Strand 167 Wilcox Hall, Box 352700, Univ. Washington, Seattle, WA 98195 voice 206-543-5350, fax 206-685-3836 skype: stuartestrand http://faculty.washington.edu/sstrand/ -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Stephen Salter Sent: Thursday, April 16, 2009 10:01 AM To: [email protected] Cc: [email protected] Subject: [geo] Re: Global Cooling John But what happens when the next, and overdue, ice age approaches and we are franticly trying to dig up all the carbon but have forgotten where we stowed it? Stephen -- Emeritus Professor of Engineering Design School of Engineering and Electronics University of Edinburgh Mayfield Road Edinburgh EH9 3JL Scotland tel +44 131 650 5704 fax +44 131 650 5702 Mobile 07795 203 195 [email protected] http://www.see.ed.ac.uk/~shs John Hampson wrote: > I would like to enquire if any consideration has been given > to ejecting "dust" from the surface of the Moon towards the Earth-Sun > Lagrange point (L1) to reduce global warming? > > My suggestion is for a base to be built on the far-side of the Moon to > eject large quantities of dust towards L1 for up to 2 weeks a month on > an ongoing basis. Initially travelling at over 2.5-km/s (5,600 mph) > the dust would decelerate along a trajectory between the Earth and > Sun, slowing to near zero at L1 before slowly dispersing. Throughout > its journey it would reduce sunlight reaching Earth. The low gravity, > absence of atmosphere and plentiful supply of surface dust on the Moon > may make this possible providing suitable trajectories exist and the > technology can be developed. Some of the problems that must be > overcome, ignoring the obvious one of getting to site, include > building a machine capable of accelerating large quantities of dust to > the required velocity (perhaps using centrifuge technology), coping > with the abrasiveness of Moon dust and providing sufficient power > (nuclear?). > > Dust ejected from the near-side of the Moon into a stable Earth orbit > might be an alternative but both options would represent fairly > desperate solutions. Costs would be high (though not necessarily more > than other options) and the technical challenges are considerable. The > pollution of space would be a major drawback, with space vehicles > requiring protection from micro-impacts. However the modest cost of > exploring the option and perhaps developing the technology, as > insurance against future disaster, might be a small price to pay if > other options fail. > > Regards > John Hampson > > > The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336. --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
