Just to clarify, we are reaping huge CDR EROI (environmental return on investment?) right now; 55% of our CO2 emissions are removed from the atmosphere annually free of charge (OK not free of environmental cost - ocean acidification). I don't think we want to consider a world without CDR. So in addition to reducing emissions, an obvious thing to do is find ways to cost-effectively and safely add to the CDR already going on. There's 2 ways to do this increase: CO2 removal and decrease natural CO2 emissions.
Using biology to do is one way to go, but using biology for C management must be done without disrupting N, P, O, H2O, etc cycles, not to mention ecosystems and food and fiber supply chains. Agree that marine biology has some advantages here, but still you are talking about a major biogeochemical and ecosystem balancing act when done at scale. Using geochemistry for C management on the other hand greatly simplifies the biogeochemical impacts not to mention alkalizes the ocean offsetting the bio and chem effects of ocean acidification. Furthermore this is the proven approach that M Nature already takes to remove excess CO2 on geologic time scales. A third alternative is to completey ignore Nature and construct a CDR machine from the ground up that will make conc CO2 from air CO2 for >$600/tonne CO2. Clearly an EROI non-starter, but unfortunately a reason given for ignoring CDR all together. But while methods of CDR can be debated, what is more troubling is the lack of a high level, policy-influencing forum to solicit, discuss, and objectively evaluate CDR merits and cost/benefit. This report to the UN is yet another example of writing off CDR without considering the full range of possibilities, including the fact that CDR is what is saving the planet right now. Perhaps we'll have to produce our own report. Greg From: [email protected] [[email protected]] on behalf of Albert Bates [[email protected]] >Sent: Wednesday, July 09, 2014 7:43 AM >To: [email protected] >Subject: [geo] Re: CO2 Briefing to Ki-Moon and the UN: Going Deep? > > >This report continues, without acknowledging, a fragile reliance on mistaken >assumptions. To wit: 2 degrees as a goal refers to a goal that may not halt >runaway warming; abating all emissions by mid-century (even if it could be >achieved given the reliance of agriculture and cities on fossil inputs) would >only afford a 10 to 30 percent chance of avoiding runaway. Holding to 1 degree >and going to zero might afford a 50 percent chance. Would you get on an >airplane if you had a 50 percent chance of crashing? I agree with the comment >that direct air capture is likely impractical when EROI is factored and >impossible in an era of sharp economic contraction. Only biochar - because of >its ability to supplant expensive fertilizers and increase food production >without additional subsidies - and agroforestry/aquaponics - because of >greater food productivity while storing C - offer any hope of going beyond >zero and into the new paradigm of net GHG sequestration from atmosphere (and ocean) to land. Redesigning civilization to accomplish this in a decade or two is the real challenge, and it is unlikely that reports such as this one will help move the discussion forward quickly enough for success in that regard. > -- >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/d/optout. > > > -- 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/d/optout.
