Dear Eric, cc. geoengineering list
There are certainly barriers to implementation of soil carbon sequestration and 4 parts per 1000 sequestration could not be met everywhere – but almost all of the soil carbon sequestration value reported in this paper are above 4 parts per 1000!! The authors conclude with the limitations – which are not actually the subject of this study – no research is presented on any of these issues – so it is a strange mixture of science showing that 4 per 1000 soil carbon sequestration can be done on almost all of the experiments they examine, and the author’s expert opinion (with no research on these issues presented in the paper) that it will be difficult to implement. It reads almost like the authors set out to show that 4 per 1000 was not feasible – found that all of the data suggested it is – and wrote that they didn’t think it is anyway. Nice data and analysis – strangely disconnected conclusions. Cheers, Pete --- Prof. Pete Smith, FRS, FRSE, FNA, FRSB Professor of Soils & Global Change (http://www.abdn.ac.uk/ibes/people/profiles/pete.smith), Science Director of Scotland's ClimateXChange (www.climatexchange.org.uk<http://www.climatexchange.org.uk/>), Editor, Global Change Biology<http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291365-2486> Editor, Global Change Biology<http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291757-1707> Bioenergy Institute of Biological and Environmental Sciences, School of Biological Sciences, University of Aberdeen, 23 St Machar Drive, Room G45 Aberdeen, AB24 3UU, Scotland, UK Tel: +44 (0)1224 272702 Fax: +44 (0)1224 272703 E-mail: [email protected]<mailto:[email protected]> Highly Cited Researcher: http://hcr.stateofinnovation.com/ Researcher ID: http://www.researcherid.com/rid/G-1041-2010 Google Scholar: http://scholar.google.co.uk/citations?user=7P9W6pYAAAAJ&hl=en From: [email protected] [mailto:[email protected]] On Behalf Of E Durbrow Sent: 28 February 2018 23:55 To: geoengineering <[email protected]> Subject: [geo] Soil carbon capture will not save us BECCS people response? http://onlinelibrary.wiley.com/doi/10.1111/gcb.14066/abstract;jsessionid=11D340C0D5B9914276D2EF84474A9A40.f04t01 Abstract We evaluated the “4 per 1000” initiative for increasing soil organic carbon (SOC) by analysing rates of SOC increase in treatments in 16 long-term experiments in southeast United Kingdom. The initiative sets a goal for SOC stock to increase by 4‰ per year in the 0–40 cm soil depth, continued over 20 years. Our experiments, on three soil types, provided 114 treatment comparisons over 7–157 years. Treatments included organic additions (incorporated by inversion ploughing), N fertilizers, introducing pasture leys into continuous arable systems, and converting arable land to woodland. In 65% of cases, SOC increases occurred at >7‰ per year in the 0–23 cm depth, approximately equivalent to 4‰ per year in the 0–40 cm depth. In the two longest running experiments (>150 years), annual farmyard manure (FYM) applications at 35 t fresh material per hectare (equivalent to approx. 3.2 t organic C/ha/year) gave SOC increases of 18‰ and 43‰ per year in the 23 cm depth during the first 20 years. Increases exceeding 7‰ per year continued for 40–60 years. In other experiments, with FYM applied at lower rates or not every year, there were increases of 3‰–8‰ per year over several decades. Other treatments gave increases between zero and 19‰ per year over various periods. We conclude that there are severe limitations to achieving the “4 per 1000” goal in practical agriculture over large areas. The reasons include (1) farmers not having the necessary resources (e.g. insufficient manure); (2) some, though not all, practices favouring SOC already widely adopted; (3) practices uneconomic for farmers—potentially overcome by changes in regulations or subsidies; (4) practices undesirable for global food security. We suggest it is more realistic to promote practices for increasing SOC based on improving soil quality and functioning as small increases can have disproportionately large beneficial impacts, though not necessarily translating into increased crop yield. Press summary https://www.sciencedaily.com/releases/2018/02/180228134114.htm -- 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]<mailto:[email protected]>. To post to this group, send email to [email protected]<mailto:[email protected]>. Visit this group at https://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout. The University of Aberdeen is a charity registered in Scotland, No SC013683. Tha Oilthigh Obar Dheathain na charthannas clàraichte ann an Alba, Àir. SC013683. -- 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 https://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
