Hi Brian, The debate between David Keith and Clive Hamilton seems sterile.
Plan A, the agreed-upon best scenario, simply won't work to prevent at least 4 degrees warming. Arguably the "carbon budget", touted in AR5, has been spent or very nearly spent already. See this short video from David Wasdell [1] for example. Thus the only way to prevent catastrophic warming and catastrophic ocean acidification is by removing CO2 faster than we are putting CO2 into the atmosphere. There is no option but to applying CDR geoengineering. The timescale on acidification may be as little as two decades to get CO2 below 350 ppm and prevent the ocean from becoming too acidic. A target of two decades may also be required to keep the future CO2 warming trajectory below 1.5 degrees C (considerably safer than 2 degrees). On top of this we have to cool the Arctic with SRM geoengineering, otherwise the albedo loss and methane forcing are liable to send global warming and climate change towards intolerable extremes. There is evidence that Arctic amplification is already causing an increase in weather extremes through disruption of the jet stream [2]. Thus Plan B has to involve both CDR and SRM. Note that social change does not come into this - except we need to explain to people that geoengineering is not some bad-dream sci-fi dangerous stuff, but practical measures, generally based on processes that occur naturally in nature, either mimicked or boosted. These measures often have extremely beneficial effects, for example putting carbon in soil as biochar can boost crops and reduce requirement for artificial fertilizer - a big contributor of CO2 to the atmosphere. Cloud brightening can reduce sea surface temperature and thereby reduce strength of hurricanes and restore fishing grounds and marine habitats. This is where both David Keith and Clive Hamilton could really help: by explaining to people, in a calm and considered way, the true situation and what can to be done about it with their moral support. Cheers, John [1] http://www.youtube.com/embed/-Fru6Df3Efk [2] http://www.nature.com/nclimate/journal/v4/n1/full/nclimate2065.html On Sat, Jan 18, 2014 at 2:54 PM, Brian Cartwright < [email protected]> wrote: > > > On Friday, January 17, 2014 4:23:25 PM UTC-5, Keith Henson wrote: >> >> "Social change" means to the advocates enforcing what they see as >> frugal morality on people, though, of course, never on the advocates. >> We on the technical fix side tend in the direction of letting people >> do fairly much whatever they want, Hummers, frequent air flights and >> all, as long as we can provide the energy and ecological support to >> let it happen. >> > > *[snipped]* > > *Yes, in this context "social change" means cutting back emissions and > promoting alternative energy, and there may be components of "frugal > morality" in that campaign. In the David vs. Clive debate, that "social > change" is, shall we say, the unspoken Plan A, the agreed-upon best > scenario. My question is, how does geoengineering, in this case SRM, get > pushed forward as Plan B? Is there no better Plan B?* > > *Briefly, there is: the imbalance of the global carbon cycle comes partly > from the pumping of CO2 emissions from fossil fuels, but equally from > depletion of global soil carbon. And unlike SRM, restoring soil carbon not > only has no harmful side-effects, but offers manifold benefits. Isn't it > puzzling that this debate is even taking place?* > > *Brian * > > > > -- > 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/groups/opt_out. > -- 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/groups/opt_out.
