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 Harte Professor of Ecosystem Sciences ERG/ESPM 310 Barrows Hall University of California Berkeley, CA 94720 USA jha...@berkeley.edu On May 31, 2015, at 8:39 PM, John Nissen <johnnissen2...@gmail.com> 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) <r.d.schuil...@uu.nl> > 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: geoengineering@googlegroups.com > [mailto:geoengineering@googlegroups.com] On Behalf Of Greg Rau > Sent: maandag 25 mei 2015 21:55 > To: geoengineering@googlegroups.com > 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 geoengineering+unsubscr...@googlegroups.com. > To post to this group, send email to geoengineering@googlegroups.com. > 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 geoengineering+unsubscr...@googlegroups.com. > To post to this group, send email to geoengineering@googlegroups.com. > 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 geoengineering+unsubscr...@googlegroups.com. > To post to this group, send email to geoengineering@googlegroups.com. > 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. 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