While perhaps worthy of a new thread, I'll insert the following link as an example of why CDR (and all other CO2 management methods) can't be ignored. Obviously, we need a radical change in our energy systems, but lots of CO2 emissions and very long term planetary damage will be done before these are in place. Hence, very proactive CO2 management must be considered (a revolution in thinking, spending, researching, evaluating and maybe implementing; not necessarily along the lines advocated in this article)
from http://qz.com/154196 "And only last week, a conference of climate scientists in London explored the theme of “radical emissions reduction” after noting that “nothing that we’ve said or done to date about climate change has made any detectable dip whatsoever”. Via a weblink, author Naomi Klein compared the fight against climate change with the struggle against South African apartheid, and said, “an agenda capable of delivering radical emissions reductions will only advance if accompanied by a radical movement.” + Fed up with slow (or in some cases, backwards) progress on climate change, environmental advocates are mulling desperate measures. Emerging at the head of this pack is arguably the world’s most prominent climate scientist: James Hansen, a former NASA researcher turned activist. + In a provocative study published earlier this month, Hansen and a group of colleagues make the case for why radical action is needed. The now commonly embraced international target of keeping global warming at a maximum of 2°Cabove pre-industrial levels—a hard-won, but politically negotiated goal—is actually much too high, Hansen says, and we should instead aim for 1°C. That would be barely a blip higher than current levels of global warming (around 0.8°C), but still the highest level ever experienced over the 10,000-year course of human civilization. ”Our objective is to define what the science indicates is needed, not to assess political feasibility,” the paper says." more follows - see link >________________________________ > From: Ronal W. Larson <[email protected]> >To: Keith Henson <[email protected]> >Cc: RAU greg <[email protected]> >Sent: Friday, December 20, 2013 8:20 AM >Subject: Re: [geo] OPEN - Reversing climate warming by artificial atmospheric >carbon-dioxide removal: can a Holocene-like climate be restored? - MacDougall >- GRL - Wiley > > > >Keith cc Greg > > > I appreciate your enthusiasm for the solar satellite approach, but I have >my hands more than full with CDR (and specifically biochar). What was the >reason the Japanese dropped their program? > > > > > >Ron > > > >On Dec 20, 2013, at 12:05 AM, Keith Henson <[email protected]> wrote: > >Would you be interested in an engineering proposal to end the use of >>fossil fuels? >> >>Warning, it does so by substituting a cheaper energy source. >> >>Keith Henson >> >>On Thu, Dec 19, 2013 at 10:33 AM, Greg Rau <[email protected]> wrote: >> >>Delayed response from me also. Just saw a brief review of this paper in my >>>hard copy of Science (Dec 6). Actual paper attached. >>> >>>While the message here seems to be "CDRer's - step away from the your >>>experiments, it's hopeless", I agree with Ron about the questionable >>>assumptions and value judgements in this paper, e.g., why a 280 ppm target, >>>why CDR only mirroring previous CO2 emissions time course, isn't some >>>hastening of CO2 removal better than no effort at all, why wait for >>>emissions to peak before initiating CDR, etc? Are we really going to solve >>>the problem via emissions reduction (and SRM) alone? Perhaps most telling is >>>the explicit assumption that machines are going to do the heavy lifting: >>> >>>"....carbon extraction begins slowly as CO2 removal machines with a finite >>>lifespan are >>>deployed at some rate. The rate of extraction grows as the machines become >>>more numerous, and new machines become more efficient. As CO2 concentration >>>approaches its >>>preindustrial concentration, the extraction rate slows as old machines are >>>no longer replaced to avoid having obsolete infrastructure when the goal of >>>280 ppmv CO2 concentration is reached." >>> >>>Why are machines necessary or even relevant? Nature naturally does air >>>capture to the tune of 55% of our emissions/yr, for free. How about figuring >>>out how to safely and cost effectively increasing this already massive air >>>capture, machines optional??? E.g., 2nd and 3rd papers attached. >>> >>>I think that the message should have been yes, post-emissions removal of CO2 >>>from air is a daunting task, but one that needs to be considered given the >>>current trajectory and ineffectiveness of our (in)actions. Also, as both Ron >>>and I appreciate, it is not necessary to remove CO2 from air to manage >>>atmospheric CO2. One can be equally effective by reducing CO2 emissions for >>>natural sources (far larger emissions than anthropogenic). E.g., by >>>reducing the degradation and CO2 regeneration from biomass (biochar, CROPS, >>>etc), by reducing ocean ventilation of CO2 via base/alkalinity addition (or, >>>with much greater care and concern, ocean fertilization), and/or other >>>methods? Or should we just kick back, enjoy our chicken McNuggets (as >>>previoiusly referenced on these pages; while they last), and rely on >>>Disneyland to recreate Great Barrier Reef and Arctic ecosystem replicas for >>>the nostalgic masses? Your call. Meantime, you are going to have to pry my >>>cold, dead fingers off of my CDR "machine" - just in case future generations >>>(humans and other biota) might be appreciative of such an effort ;-) >>>Greg >>> >>>________________________________ >>>From: Ronal W. Larson <[email protected]> >>>To: Andrew Lockley <[email protected]> >>>Cc: Geoengineering <[email protected]> >>>Sent: Sunday, December 15, 2013 2:54 PM >>>Subject: Re: [geo] OPEN - Reversing climate warming by artificial >>>atmospheric carbon-dioxide removal: can a Holocene-like climate be restored? >>>- MacDougall - GRL - Wiley >>> >>>Andrew and list >>> >>> 1. I have been meaning to comment on this article by Dr. Andrew >>>MacDougall, that you cited in October. I was reminded by it being >>>referenced in the last Science issue (Dec. 6, p 1149) I received. The >>>article is NOT behind a paywall. It is at: >>>http://onlinelibrary.wiley.com/store/10.1002/2013GL057467/asset/grl51021.pdf?v=1&t=hp8v0lqy&s=27b2334b807e010482b6e4fa3f41a8703797473f >>> >>> 2. I took the main result to be quite negative for CDR. But there still >>>some positives to gain from an analysis I believe can be improved. The >>>faults I find are only in the papers four scenarios, which are: >>> >>> a) that only as much carbon can be removed from the atmosphere as was >>>inserted (no explanation on why this limit), and >>> >>> b) is to be taken out as a “mirror” of the way it was inserted (and I >>>am not understanding details of the mirror, but this seems highly >>>unrealistic), and >>> >>> c) requires going back to 280 ppm (not the usual 350 ppm) >>> >>> d) looking at very high out year peaks, that are inconsistent with the >>>concept of CDR. >>> >>> 3. I am of course unhappy that there is nothing about biochar in this >>>article (for out-of-date reasons), but the specifics of the CDR approach are >>>not critical and are not I believe in the model. There are a number of >>>useful references to somewhat similar papers. There is no sense of >>>“Irreversibility”. >>> >>> So I am still hoping to see modeling as detailed as in this paper, that >>>includes the potential for more soil carbon. There are some out year >>>freebies with biochar that have not been modeled by any group, to my >>>knowledge. To the best of my knowledge none of the removed CO2 ends up in >>>soil. >>> >>> The model is better than many by including Arctic methane release. The >>>long time periods to reach the year-1850 conditions are because of the four >>>faults I am claiming above in the four assumed scenarios. These should be >>>readily fixable. >>> >>> 4. The positives that I think we can take from the article relate to >>>what can happen with more realistic scenarios, which should have these four >>>features, that replace the above #2 assumptions: >>> >>> a) No limitations on the amounts that can eventually be removed from >>>the atmosphere. >>> (The required removal amounts are a very small percentage of >>>CO2 in the oceans, or allowed deep underground - and I know of no reason >>>that soil carbon couldn’t be doubled or tripled without harm.) >>> >>> b) Use annual removals that emphasize speed and are reasonably least >>>cost - not a “mirror” of anything. >>> (For biochar options, the limiting speed at first will be the >>>manufacture of pyrolysis hardware - which presumably could have a doubling >>>time at first measured in months. For sure, the output of such factories >>>will not be time-independent, so the growth rate should not be linear. >>>When a production plateau will be reached is a function of costs and >>>benefits, which can be controlled by policy decisions ($10 or $100/tonne >>>CO2, etc). This can be handled parametrically, with numbers like 1, 10 or >>>more Gt C/yr being assumed and costed. The important point is that for >>>decades I think we can assume an annual increase in removal, not the annual >>>decrease that (I think) is in the MacDougall model. I would hope for a >>>model that talks of getting to 350 ppm well before 2100. >>> >>> c) First investigate the 350 ppm end point; continue to 280 ppm as a >>>second stage effort. >>> (350 ppm just because there has been so much emphasis on that >>>number. 280 ppm should certainly be modeled as well.) >>> >>> d) I would restrict attention at first only to the two lowest of the >>>new IPCC AR5 peak scenarios. I believe his present analyses already >>>adequately argue against the two higher. >>> >>> >>>5. So, I hope that Dr. MacDougall or others will extend his analyses in >>>these directions. The cause of CDR can be enhanced by trying to achieve >>>what some climate scientists are saying we need to do - or showing why it >>>cannot be. Lower ultimate costs will result by striving for speed and >>>avoiding terms like “the year 3000” (in the abstract). >>> To repeat, I am not intending to be critical of this paper. I believe >>>the results are reasonably correct for the assumed scenario. I am >>>suggesting we need also to look at scenarios that are much less restrictive. >>> >>>Ron >>> >>> >>>On Oct 8, 2013, at 3:18 AM, Andrew Lockley <[email protected]> wrote: >>> >>>http://onlinelibrary.wiley.com/doi/10.1002/2013GL057467/abstract >>>Reversing climate warming by artificial atmospheric carbon-dioxide removal: >>>can a Holocene-like climate be restored? >>>Andrew. H. MacDougall >>>DOI: 10.1002/2013GL057467 >>>Geophysical Research Letters >>>Keywords: >>>Holocene;Climate warming;Reversibility >>>Abstract >>>Most climate modelling studies of future climate have focused on the affects >>>of carbon emissions in the present century or the long-term fate of >>>anthropogenically emitted carbon. However, after carbon emissions cease >>>there may be a desire to return to a “safe" CO2 concentration within this >>>millennium. Realistically this implies artificially removing CO 2 from the >>>atmosphere. In this study experiments are conducted using the University of >>>Victoria Earth system climate model forced with novelfuture scenarios to >>>explore the reversibility of climate warming as a response to a gradual >>>return to pre-industrial radiative forcing. Due to hysteresis in the >>>permafrost carbon pool the quantity of carbon that must be removed from the >>>atmosphere is larger than the quantity that was originally emitted (115–180% >>>of original emissions). In all the reversibility simulations with a moderate >>>climate sensitivity a climate resembling that of the Holocene can be >>>restored by 3000 CE. >>> >>>-- >>>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. >>> >>> >>>-- >>>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. 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