John, list, et al: Apologies if this comes to you twice. Am still at the conference hotel and have had trouble sending. This time much shorter.
> On Aug 25, 2016, at 9:08 AM, Ronal W. Larson <rongretlar...@comcast.net> > wrote: > > John, list et al: > > Re your almost last sentence(emphasis added): > “BTW, I would also recommend an ambition to restore land and ocean > productivity to their levels of a few thousand years ago, before mankind > started to denude soils and sea of nutrients.” > I am pleased to report that we have just finished the 2016 Biochar > conference at Oregon State University (Corvallis, OR), and that great > progress has been made since our last in 2013. I would guess at least three > times more commercial presence and activity than then. Many new reports of > cost effectiveness - even as little as one-year payback. > I would amend your sentence to express an ambition not to restore but > to double. > > Ron > > >> On Aug 25, 2016, at 6:25 AM, John Nissen <johnnissen2...@gmail.com >> <mailto:johnnissen2...@gmail.com>> wrote: >> >> Dear Benjamin, >> >> I should have mentioned olivine crushing because it has a huge role to play >> in bringing down the level of CO2 in the atmosphere, for example directly by >> scattering on the beach or indirectly by promoting diatoms or soil >> improvement. >> >> Re emissions reductions, I probably made a mistake in my earlier email, >> because I was assuming the maximum rate of emissions reduction, suggested to >> be 7% per annum, was an exponential reduction with a halving of emissions >> every 10 years and thus never reaching zero. But the rate will be more >> linear than that, making it feasible to obtain an emissions reduction to 30% >> in 10 years and to near zero in 15 years. >> >> As well as this reduction, starting now, I propose immediate aggressive CDR >> over the next 10 years (including olivine crushing, biochar and ocean >> fertilisation) to obtain an equalisation of drawdown with emissions, thus >> achieving a zero net input of CO2 to the atmosphere, aka "carbon >> neutrality", by ~2025. This will be the peak of CO2 level in the >> atmosphere. The CDR will be exactly offsetting 30% the current level of >> emissions, assuming that maximum 7% annual reduction is maintained over the >> 10 years. >> >> CDR should continue to be ramped up over the following 20 years, to obtain a >> halving and then a quartering of the climate forcing due to excess CO2 in >> the atmosphere, i.e. taking the level from its peak in ~2025 down to 340 ppm >> and then to 310 ppm. >> >> If IPCC were to accept this as a legitimate "representative concentration >> pathway", then there could be the ambition of climate restoration by 2050, >> with CO2 and CO2eq back to near pre-industrial levels resulting in a >> cessation of global warming well below the <2C target. >> >> In addition to CDR, there would need to be measures to reduce non-CO2 >> forcing agents: to reduce fugitive methane: to suppress methane from the >> Arctic and from wetlands; to reduce black carbon, especially from tundra >> fires; and, most urgently, to save the sea ice, prevent disintegration of >> the Greenland Ice Sheet and restore albedo in the Arctic. The ambition >> might be to restore the levels of albedo and greenhouse forcing agents to >> their pre-industrial levels by 2050. >> >> BTW, I would also recommend an ambition to restore land and ocean >> productivity to their levels of a few thousand years ago, before mankind >> started to denude soils and sea of nutrients. >> >> I am looking forward to your response. >> >> Kind regards, John >> >> >> On Tue, Aug 23, 2016 at 9:00 AM, Schuiling, R.D. (Olaf) <r.d.schuil...@uu.nl >> <mailto:r.d.schuil...@uu.nl>> wrote: <Snip> -- 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 https://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.