Hi all, What about marine cloud brightening to try and save the Arctic sea ice, which is starting to collapse in extent right at this moment? The repercussions of sea ice disappearance are well known and include the threat of a methane excursion and Greenland Ice Sheet destabilisation [1]. More recently, the polar amplification, which will increase as the sea ice disappears, has been shown to be implicated in polar jet stream disruption, leading to climate extremes [2]. Events such as the current drought in US mid-west are now being associated with jet stream behaviour. Crops have failed in many parts of the world. Food prices are going up, and the World Bank has issued a global hunger alert [3]. But this situation can only get worse with the Arctic warming even faster.
What can be done to avert disaster? It is obvious that we have to cool the Arctic - but how? For those who suggest we may even be too late for geoengineering, do we have any other option? Surely we should be trying to get cloud brightening and other cooling technologies into operation as soon as humanly possible. This surely is a topic of extreme importance for discussion on this list. John [1] “Our greatest concern is that loss of Arctic sea ice creates a grave threat of passing two other tipping points -- the potential instability of the Greenland ice sheet and methane hydrates. These latter two tipping points would have consequences that are practically irreversible on time scales of relevance to humanity.” Hansen [2] http://e360.yale.edu/feature/linking_weird_weather_to_rapid_warming_of_the_arctic/2501/ [3] http://www.theindependentbd.com/paper-edition/oped/129460-world-bank-issues-global-hunger-alert.html -- On Tue, Sep 4, 2012 at 6:37 PM, Rau, Greg <r...@llnl.gov> wrote: > GEOENGINEERING: > Scientists suggest 'cloud brightening' to halt hurricanes > Published: Tuesday, September 4, 2012 > Brightening clouds over hurricane-forming areas of the oceans could lower > sea-surface temperatures and deprive storms of the heat they need to become > tropical storms or hurricanes, says a team of atmospheric scientists. > > "We're probably a couple of years away from being able to conduct field > tests," said lead author John Latham of the University of Manchester, > England. "But as these things go, it probably wouldn't be very expensive." > > The researchers presented their findings in the journal Atmospheric > Science Letters. > > Marine cloud brightening is among many geoengineering technologies that > aim to cool the planet by decreasing the amount of incoming solar > radiation, preventing greenhouse gases from entering the atmosphere or > absorbing some of the heat-trapping gases that are already in the > atmosphere. > > With marine cloud brightening, scientist propose to spray microscopic > droplets of seawater into clouds, which would make the clouds more > reflective, thereby bouncing incoming solar radiation back into space. > Unmanned aircraft might be used to spray the clouds. > > Latham suggests that a smaller-scale marine cloud brightening process > targeting patches of oceans where storms are forming could lower > sea-surface temperatures and reduce storm intensity. > > "The way it stands at the moment," Latham said, "is that if we can get > this to work, it should be possible to choose where to seed, both on basis > of cooling the surface water, but also on not cooling over land in regions > that won't tolerate it." > > More theoretical work is necessary before even small-scale experiments can > be done, Latham said (Michael Lemonick, Climate Central, Aug. 29). -- RE > > -- > 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.
