Increasing CO2 threatens human nutrition
Authors: Samuel S Myers
N Michele Holbrook
Michael Tausz
Saman Seneweera
Hidemitsu Sakai
Arnold J Bloom
Michael J Ottman
Glenn Fitzgerald
Itai Kloog
Andrew D B Leakey
Toshihiro Hasegawa
Joel Schwartz
Yasuhiro Usui
Karla A Sartor
Lee H Dietterich
Randall L Nelson
Antonella Zanobetti
Victor Raboy
Peter Huybers
Eli Carlisle
Journal: Nature (2014)
Discipline: Multidisciplinary
Keywords: Dietary deficiencies; zinc; iron; C3 grains; legumes
Affiliations: 1] Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, 02215, USA [2] Harvard University Center for the Environment, Cambridge, Massachusetts 02138, USA., Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, 02215, USA., The Department of Geography and Environmental Development, Ben-Gurion University of the Negev, PO Box 653, Beer Sheva, Israel., Department of Earth and Planetary Science, Harvard University, Cambridge, Massachusetts 02138, USA., Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA., Department of Plant Sciences, University of California at Davis, Davis, California 95616, USA., University of Pennsylvania, Department of Biology, Philadelphia, Pennsylvania 19104, USA., Department of Environment and Primary Industries, Horsham, Victoria 3001, Australia., National Institute for Agro-Environmental Sciences, Tsukuba, Ibaraki, 305-8604, Japan., Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138, USA., United States Department of Agriculture Agricultural Research Service, Soybean/Maize Germplasm, Pathology, and Genetics Research Unit, Department of Crop Sciences, University of Illinois, Urbana, Illinois 61801, USA., School of Plant Sciences, University of Arizona, Tucson, Arizona 85721, USA., United States Department of Agriculture Agricultural Research Service, Aberdeen, Idaho 83210, USA., The Nature Conservancy, Santa Fe, New Mexico 87544, USA., Department of Agriculture and Food Systems, Melbourne School of Land and Environment, The University of Melbourne, Creswick, Victoria 3363, Australia., Department of Forest and Ecosystem Science, Melbourne School of Land and Environment, The University of Melbourne, Creswick, Victoria 3363, Australia.

Abstract:  Dietary deficiencies of zinc and iron are a substantial global public health problem. An estimated two billion people suffer these deficiencies, causing a loss of 63 million life-years annually. Most of these people depend on C3 grains and legumes as their primary dietary source of zinc and iron. Here we report that C3 grains and legumes have lower concentrations of zinc and iron when grown under field conditions at the elevated atmospheric CO2 concentration predicted for the middle of this century. C3 crops other than legumes also have lower concentrations of protein, whereas C4 crops seem to be less affected. Differences between cultivars of a single crop suggest that breeding for decreased sensitivity to atmospheric CO2 concentration could partly address these new challenges to global health. 

Retracted: No

PubPeer comments:
null, 
 Peer1 asserted that Myers et al exaggerated the size of their data set with claims it s 10X  relative to the published literature . Peer1 did not support her assertion with hard numerical values. There is no effortless way to review all the published publications to verify the assertion. Luckily the same time as Nature published the study of Myers et al, a different study was published by ELife on the same question that compiled and analyzed the published literature. This provides an opportune to compare the studies to check the veracity of Peer1u2019s assertion that Myers et al exaggerated the scope of the study relative to the published literature. Our group is in the process of collecting data on nutritional values in relation to climate change and we cared to run descriptive statistics on the two studies. The numbers speak for themselves. | Journal | eLife | Nature | |:-------------------------------------:|:-------------------:|:------------------------:| | publication date | 7 May 2014 | 7 May 2014 | | author(s) | Loladze | Myers et al | | open-access | Yes | No`*` | | raw data included | Yes | No`*` | | software code made available | Yes | No | | author(s) | 1 | 20 | | funding agencies | 0 | 15 | | chemical elements studied | 27 | 11 + phytate | | C3 plant varieties covered | 125 | 38 | | C4 plant varieties covered | 5 | 3 | | plant tissues types included | 15 | 3 | | continents included | 4 | 3 | | countries included | 13 | 3 | | FACE observations covered | 4,528 | 12,672 | | Open Top Chamber observations covered | 4,498 | 0 | | greenhouse observations included | 2,536 | 0 | | chamber tunnel observations | 3,448 | 0 | | all observations covered | 15,522 (7761 pairs) | 12,672 (with duplicates) | `*` Unfortunately, we were unable to locate the raw data in the Nature supplements. Peer1 comment directed us to Dietterich et al (2015). Itu2019s open-access and appears to contain the raw data for the Nature manuscript. We used Dietterich et al to generate the descriptor statistics for the Nature column. , 
 Trichostema P. calculate that Myers et al. (2014) analyzed 12672 observations of nutrient concentrations from FACE experiments. The single biggest contributor to this dataset is the AGFACE wheat experiment in Australia, 2007-2009, with 5632 observations. The analysis of wheat grain quality in response to elevated CO2 using the AGFACE data appears to be published by Fernando et al a few months prior to Myers et al. (2014): Fernando, Nimesha, et al.  Intra-specific variation of wheat grain quality in response to elevated [CO 2] at two sowing times under rain-fed and irrigation treatments. Journal of Cereal Science 59.2 (2014): 137-144. N. Fernando is not listed among the authors of Myers et al. (2014) Nature. The exclusion of the AGFACE data indicates the analysis of new data in the Nature paper is restricted to 7040 observations or less. The methods in the Nature paper are scant and hopefully Myers et al. could provide answers about the extent of their dataset. , 
 commenter #2: your table appears to be troubling; could you verify the figures with links to the two data-sets ? how can a Harvard-led team of twenty backed up by fifteen grants fall short of the analysis done by one author with zero funding? , 
 Neophaeosphaeria Agaves (#4), we are able to answer your 1st question but not the 2nd. The Methods and Materials in the Elife manuscript point to this [location](http: dx.doi.org 10.5061 dryad.6356f) for the dataset, and to a GitHub depository https: github.com loladze co2 for the code. Peer1 (#1) commented that the Nature manuscript provides no supporting dataset. We were not able to locate it in the supplements or Methods in the Nature journal. Peer1 (#1) comments directed us to Dietterich et al (2015) manuscript that appears to contain the supporting dataset for the Nature manuscript at this [location.](http: dx.doi.org 10.6084 m9.figshare.1399218) , 
 commenter #2: thanks for the links. this must be galling for Nature. for the sake of impact factors they let authors inflate the size of their data-set that is conveniently left out of supplements. sigh , 
 #6 to be precise: the number of observations published prior to Myers et al. (2014) is 15522 (per #2 table) + 5632 (Fernando et al. 2014) = 21164 . Of those 4528 + 5632 = 10160 are FACE observations, which is more than 7040 observations generated by Myers et al. (2014). Claiming 7040 is  tenfold more than 10160 means the Nature paper inflated the scope of the study by 101600 7040 = 14.4 times or 1440%. Am I missing something here? Hopefully Myers et al. could provide some explanation or correction. , 
 The thread here raises concerns about the exaggerations made by Myers et al with respect to the size of their studies. This should not cast doubts on the negative nutrient responses in crops to increased carbon dioxide in the atmosphere. #2 pointed out to studies showing nutrients appear to have a lower density in a wide type of agricultural crops in Loladze (2014) and (for less nutrients) in Myers (2014) , 
 Concerns raised on this forum by a number of peers about the misappropriation of credit may have had a positive outcome. The journal *Nature* published an correction available at this [location] : **Published: 01 October 2019** **Author Correction: Increasing CO2 threatens human nutrition** Samuel S. Myers, Antonella Zanobetti, Itai Kloog, Peter Huybers, Andrew D. B. Leakey, Arnold J. Bloom, Eli Carlisle, Lee H. Dietterich, Glenn Fitzgerald, Toshihiro Hasegawa, N. Michele Holbrook, Randall L. Nelson, Michael J. Ottman, Victor Raboy, Hidemitsu Sakai, Karla A. Sartor, Joel Schwartz, Saman Seneweera, Michael Tausz Yasuhiro Usui Nature volume 574, page E14 (2019) Correction to: Nature https: doi.org 10.1038 nature13179, published online 07 May 2014. In this Letter, we ought to have cited four relevant references. The first two (1,2), published after submission of the first version of our manuscript, report a cultivar-dependent reduction in wheat grain quality under elevated carbon dioxide (CO2) in an Australian Grains Free-Air Carbon dioxide Enrichment (AGFACE) experiment. A subset of these results was reported in two papers published in 2012 (refs. 3,4). Although our work was independent of these papers, we regret not citing them to highlight their relevance. The original Letter has not been corrected. References 1. Fernando, N. et al. Intra-specific variation of wheat grain quality in response to elevated [CO2] at two sowing times under rain-fed and irrigation treatments. J. Cereal Sci. 59, 137u2013144 (2013). 2. Fernando, N. et al. Elevated CO2 alters grain quality of two bread wheat cultivars grown under different environmental conditions. Agric. Ecosyst. Environ. 185, 24u201333 (2013). 3. Fernando, N. et al. Rising atmospheric CO2 concentration affects mineral nutrient and protein concentration of wheat grain. Food Chem. 133, 1307u20131311 (2012). 4. Fernando, N. et al. Wheat grain quality under increasing atmospheric CO2 concentrations in a semi-arid cropping system. J. Cereal Sci. 56, 684u2013690 (2012). ,