I'd say that we are nowhere near reducing global emissions by 2-3% per year let alone getting to zero emissions. This would seem to up the chances that we are going to blow through a critical CO2 level which could last more than 85 years, depending. E.g., if the 2 degree threshold is real and only requires 1000 Gt more of CO2 emissions to achieve, miraculously stabilizing anthro emissions at current levels, 37 Gt CO2/yr, gets us to the next 1Tt of CO2 emitted in under 30 years. Those trying to conserve glacial and sea ice and permafrost might say we've already passed a point of no return.
So I side with caution and John N. At our current pace of year-to-year global CO2 emissions reductions (nonexistent) and with clear AGW and OA, it is time to seriously ask what are all of our options for managing CO2 and its consequences. As pointed out in this thread, natural CO2 sinks are already saving our bacon to the tune by some 18 Gt CO2/yr removed from air. Is it unthinkable that we cannot increase this uptake by enhancing existing sinks or inventing new ones that can compete on a cost and efficiency basis with other methods of CO2 management? In this regard, making supercritical CO2 from dilute sources and storing it underground (BECCS) is a nonstarter from a thermodynamics standpoint, not to mention land use impacts of biomass production plus safety and security issues of underground molecular CO2 storage. Do we really want the CCS lobby and marketing machine to monopolize the CDR space, as they have point-source CO2 mitigation, at the expense of a much broader search for safer and more cost effective CO2 managment strategies, thus holding hostage any significant movement in mitigating pre- or post-emissions fossil fuel CO2? And, given what is at stake, can we really afford to limit ourselves to using less than 30% of the planet in solving a global problem, i.e., ignore the ocean? I therefore find IPCC's NAS's and now the World Bank's promotion of aforestation and BECCS as the poster children of CDR dangerously narrow minded. Greg -------------------------------------------- On Tue, 6/9/15, John Harte <[email protected]> wrote: Subject: Re: [geo] World Bank report highlights necessity of (BE)CCS To: "John Nissen" <[email protected]> Cc: "Schuiling, R.D. (Olaf)" <[email protected]>, "[email protected]" <[email protected]>, "[email protected]" <[email protected]>, "Peter R Carter" <[email protected]>, "Oliver Tickell" <[email protected]> Date: Tuesday, June 9, 2015, 3:38 PM John, rather than forgetting that, it is exactly the point I am making. But it's not half of the actual emitted carbon that goes down the sink; it is a quantity of carbon equal to half the emitted carbon. So if we emit no carbon next year, at the end of the year there will be 4 or 5 Gt less carbon in the atmosphere. Modeling this out 85 years with a simple gradient-driven (and thus diminishing) sink rate suggests that by end of century there could be substantially reduced atmospheric CO2…even in a scenario in which emissions are reduced by ~ 2 or 3% per year. John HarteProfessor of Ecosystem SciencesERG/ESPM310 Barrows HallUniversity of CaliforniaBerkeley, CA 94720 [email protected] On Jun 9, 2015, at 3:25 PM, John Nissen <[email protected]> wrote: Hi John, I think you may be forgetting that about half the CO2 emitted is immediately absorbed by land and oceans. The other half has a long lifetime, measured in centuries (and a fraction of that measured in millennia). Thus reducing emissions to zero would only produce a gradual reduction in the atmospheric CO2 level. Therefore active CO2 removal (CDR) is essential for quickly reducing that level to a safe value: somewhere in mid 300s of ppm. Cheers, John (just back from holiday and a conference on ocean acidification) On Wed, Jun 3, 2015 at 1:00 AM, John Harte <[email protected]> wrote: Recall that the natural sink strength today is about 4 or 5 Gt(C)/y … there is no reason to think that this sink strength, which is effectively driven by the difference between the current atmospheric concentration and the concentration in an atmosphere in equilibrium with the current ocean concentration, and which sink has been increasing since 1990, would rapidly quench until the atmospheric concentration is well down into the mid 300's ppm range. Hence if we reduce emissions down to a level of roughly 4 or 5 Gt(C)/y we will see the atmospheric level roughly stabilize and if reduce emissions to zero, we will see the atmospheric level drop at a very beneficial pace. What would invalidate this projection is crossing a tipping point in which warming results in a sharp increase in background C or CH4 emissions (effectively a negative sink) but the paleo record does not suggest that such tipping points are lurking at current or even slightly higher temperatures. If we do not reduce emissions, there is a of course a better chance that we will cross such tipping points in the coming century. John HarteProfessor of Ecosystem SciencesERG/ESPM310 Barrows HallUniversity of CaliforniaBerkeley, CA 94720 [email protected] On May 31, 2015, at 8:39 PM, John Nissen <[email protected]> wrote: IPCC and the World bank ignore that we need ramp up removal technologies until we are removing more CO2 than we are putting into the atmosphere. This ramp up needs to start straight away, if we are to have a reasonable chance of avoiding both dangerous global warming and dangerous ocean acidification. CCS reduces emissions of CO2 into the atmosphere, but does not actually remove CO2 as needed to get the level safely below 350 ppm or so. There should be a formal complaint to IPCC about this, as for some other issues. Cheers, John On Tue, May 26, 2015 at 8:53 AM, Schuiling, R.D. (Olaf) <[email protected]> wrote: A serious lack of knowledge about natural processes. A million times more CO2 has been stored by nature in carbonate rocks than is present in the oceans, atmosphere and biosphere combined, and not a word about it, Olaf Schuiling -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Greg Rau Sent: maandag 25 mei 2015 21:55 To: [email protected] Subject: [geo] World Bank report highlights necessity of (BE)CCS http://bellona.org/news/climate-change/2015-05-world-bank-report-highlights-necessity-ccs “We need Bio-CCS to attain carbon neutrality by 2100” "This statement forms a key area of scientific consensus, shared by the IPCC in the 5AR and acknowledged by the World Bank’s report. Achieving the 2°C target will necessitate negative emissions in the second part of this century. This can be achieved through the combination of sustainable bioenergy with CCS. Find out how it works here." GR - So says CCS promoters, completely ignoring numerous other C-negative technologies. "Importantly, the report warns that beyond 2030, the scenarios in which CCS is not available or not deployed at scale, the negative emissions required to keep temperature change below 2°C or even 3°C have to be generated from the agriculture, forestry, and other land-use sectors, creating immense challenges in land-use management." GR - Completely ignores ocean-based C-negative technologies. Who says that C-negative methods must be limited to <30% of the Earth's surface, much of which is already critical for other uses/services? "With regards to decarbonisation of the electricity sector, the report argues that the share of low-carbon or negative-carbon energy must rise from less than 20% in 2010 to about 60% in 2050. This is an increase of more than 300% over 40 years." GR- There is no way this is going to happen if we limit ourselves to making concentrated CO2 from flue gas and storing it in the ground - (BE)CCS. We need to expand RD&D, marketing and policy way beyond CCS. But how will this happen as long as well funded, vested interests continue to sell CCS as the only viable technology? "The report argues that oil and gas companies can in a similar fashion reinvent themselves if they develop CCS technology. A Bellona study has in fact found that the jobs and skills of today’s North Sea petroleum industry could largely be preserved when transformed into a CO2 storage industry." GR - At last, the real reason to promote CCS, whether or not it makes technical or economic sense and can compete with other technologies. The habitability of the planet held hostage by petroleum industry jobs. Sound familiar? -- 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. 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