Short Note    Peer-Reviewed

The GHG Protein Ratio: An Indicator Whose Time Has Come

James A. Dyer 1,†,* and Raymond L. Desjardins 2,†
Ag-environmental Consultant, 122 Hexam Street, Cambridge, ON N3H 3Z9, Canada
Science and Technology Branch, Agriculture and Agri-Food Canada, 960 Carling Avenue, Ottawa, ON K1A 0C6, Canada
These authors contributed equally to this work.
For correspondence.
Academic Editor:
Highlights Sustain. 2022, 1(2), 105–112.
Received: 16 February 2022    Accepted: 30 May 2022    Published: 2 June 2022
The Carbon Footprint (CF) of agriculture must be substantially reduced to help avoid catastrophic climate change. This paper examines the ratio of Greenhouse Gas (GHG) emissions to protein as an indicator of the CF of the major Canadian livestock commodities using previously published results. The GHG emissions for these commodities were estimated with a spreadsheet model that accounted for all three GHGs, the complete life cycles of each livestock type and the livestock interactions with the agricultural land base. The indicator results reviewed here included the responses to livestock types and diets, livestock versus plant protein sources, spatial scales and geographic differences. The sensitivity of the results shown suggest that GHG-protein ratios could provide valuable guidance for producers and consumers to reduce their GHG emissions. For example, diverting feed grains from beef feedlots to hog production would substantially reduce the CF of red meat, although still not as low as the CF of poultry products. The complete proteins derived from pulses have much lower CF values than all livestock products.
Copyright © 2022 Dyer and Desjardins. This article is distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use and distribution provided that the original work is properly cited.
This research was partly funded by the Sustainability Metric project of Agriculture and Agri-Food Canada.
Cite this Article
ACS Style
Dyer, J.A.; Desjardins, R.L. The GHG Protein Ratio: An Indicator Whose Time Has Come. Highlights Sustain. 2022, 1, 105–112.
APA Style
Dyer, J. A., & Desjardins, R. L. (2022). The GHG Protein Ratio: An Indicator Whose Time Has Come. Highlights of Sustainability, 1(2), 105–112.
Capper, J.L.; Bauman, D.E. The role of productivity in improving the environmental sustainability of ruminant production systems. Annu. Rev. Anim. Biosci. 2013, 1, 469–489.
Gunnars, K. Protein Intake How Much Protein Should You Eat per Day? Healthline Newsletter, 1 October 2020. Available online: (accessed 4 December 2021).
Dyer, J.A.; Vergé, X.P.C.; Desjardins, R.L.; Worth, D.E. The protein-based GHG emission intensity for livestock products in Canada. J. Sustain. Agric. 2010, 34, 618–629.
Nardone, A.; Ronchi, B.; Lacetera, N.; Ranieri, M.S.; Bernabucci, U. Effects of climate changes on animal production and sustainability of livestock systems. Livest. Sci. 2010, 130, 57–69.
Willard, B. Colouring outside the lines: symbolic legitimacy for Americans. In Meatsplaining: The Animal Industry and the Rhetoric of Denial; Hannan, J., Ed.; Sydney University Press: Sydney, Australia, 2020; Chapter 5, pp. 135–161.
Poore, J.; Nemecek, T. Reducing food’s environmental impacts through producers and consumer. Science 2018, 360, 987–992.
De Vries, M.; de Boer, I.J.M. Comparing environmental impacts for livestock products: A review of life cycle assessments. Livest. Sci. 2010, 128, 1–11.
González, A.D.; Frostell, B.; Carlsson-Kanyama, A. Protein efficiency per unit energy and per unit greenhouse gas emissions: Potential contribution of diet choices to climate change mitigation. Food Policy 2011, 36, 562–570.
Nijdam, D.; Rood, T.; Westhoek, H. The price of protein: review of land use and carbon footprints from life cycle assessments of animal food products and their substitutes. Food Policy 2012, 37, 760–770.
Vauterin, A.; Steiner, B.; Sillman, J.; Kahiluoto, H. The potential of insect protein to reduce food-based carbon footprints in Europe: the case of broiler meat production. J. Clea. Prod. 2021, 320, 128799.
MacLeod, M.J.; Vellinga, T.; Opio, C.; Falcucci, A.; Tempio, G.; Henderson, B.; Makkar, H.; Mottet, A.; Robinson, T.; Steinfeld, H.; et al. Invited review: A position on the Global Livestock Environmental Assessment Model (GLEAM). Animal 2018, 12, 383–397.
Hedenus, F.; Wirsenius, S.; Johansson, D.J.A. The importance of reduced meat and dairy consumption for meeting stringent climate change targets. Clim. Chang. 2014, 124, 79–91.
Mayer, A. Meat and the Environment: Do Canadians Know What’s at Stake? what on Earth? CBC News, 19 April 2019. Available online: (accessed 4 December 2021).
Dyer, J.A.; Worth, D.E.; Vergé, X.P.C.; Desjardins, R.L. Impact of recommended red meat consumption in Canada on the carbon footprint of Canadian livestock production. J. Clean. Prod. 2020, 266, 121785.
Dyer, J.A.; Vergé, X.P.C.; Desjardins, R.L.; Worth, D.E. A comparison of the greenhouse gas emissions from the sheep industry with beef production in Canada. Sustain. Agric. Resh. 2014, 3, 65–75.
Table 32-10-0359-01 Estimated areas, yield, production, average farm price and total farm value of principal field crops, in metric and imperial units. Statistics Canada: Ottawa, Canada, 6 May 2022.
Dyer, J.A.; Desjardins, R.L. Reconciling reduced red meat consumption in Canada with regenerative grazing: implications for GHG emissions, protein supply and land use. Atmosphere 2021, 12, 945.
Dyer, J.A.; Vergé, X.P. The Role of Canadian Agriculture in Meeting Increased Global Protein Demand with Low Carbon Emitting Production. Agronomy 2015, 5, 569–586.
Dyer, J.A.; Vergé, X.P.C.; Desjardins, R.L.; Worth, D.E. District scale GHG emission indicators for Canadian field crop and livestock production. Agronomy 2018, 8, 190.
Dyer, J.A.; Desjardins, R.L.; Worth, D.E.; Vergé, X.P.C. Potential role for consumers to reduce Canadian agricultural GHG emissions by diversifying animal protein sources. Sustainability 2020, 12, 5466.
Dyer, J.; Desjardins, R. Protein as a unifying metric for carbon footprinting livestock. Research Outreach publication (Earth & Environment). Issue 118: 142–145. (accessed 4 December 2021).
University of Reading. Human gut unable to unlock majority of protein from many plant ‘milks’. Available online: (accessed 15 February 2022).
Vergé, X.P.C.; Dyer, J.A.; Desjardins, R.L.; Worth, D. Greenhouse gas emissions from the Canadian dairy industry during 2001. Agric. Syst. 2007, 94, 683–693.
Vergé, X.P.C.; Dyer, J.A.; Desjardins, R.L.; Worth, D. Greenhouse gas emissions from the Canadian beef industry. Agric. Syst. 2008, 98, 126–134.
Vergé, X.P.C.; Dyer, J.A.; Desjardins, R.L.; Worth, D. Greenhouse gas emissions from the Canadian pork industry. Livest. Sci. 2009, 121, 92–101.
Vergé, X.P.C.; Dyer, J.A.; Desjardins, R.L.; Worth, D. Long Term trends in greenhouse gas emissions from the Canadian poultry industry. J. Appl. Poult. Res. 2009, 18, 210–222.
Vergé, X.P.C.; Dyer, J.A.; Worth, D.; Smith, W.N.; Desjardins, R.L.; McConkey, B.G. A greenhouse gas and soil carbon model for estimating the carbon footprint of livestock production in Canada. Animals 2012, 2, 437–454.
Dyer, J.A.; Vergé, X.P.C.; Desjardins, R.L.; Worth, D.E. An assessment of greenhouse gas emissions from co-grazing sheep and beef in Western Canadian rangeland. In Agricultural Management for Climate Change; Lac, S., Kulshreshtha, S., McHenry, M., Eds.; Nova Science Publishers Inc.: New Nork, NY, USA, 2015; Chapter 2, pp. 13–29.
Flanagan, R., What’s on your plate? Inside the changes to Canada’s Food Guide. CTVNews, 23 January 2019. Available online: (accessed 29 November 2021).
VandenBygaart, A.J.; McConkey, B.G.; Angers, A.D.; Smith, W.; De Gooijer, H.; Bentham, M.; Martin, T. Soil carbon change factors for the Canadian agriculture national greenhouse gas inventory. Can. J. Soil Sci. 2008, 88, 671–680.
Capper, J.L. The sustainability and ‘carbon footprints’ of conventional and alternative beef production systems. In Ensuring Safety and Quality in the Production of Beef, Volume 2. Burleigh Dodds Science Publishing Limited: Cambridge, UK, 2017; pp. 1–27.
Carrington, D. Giving up beef will reduce carbon footprint more than cars. The Guardian, 21 July 2014. Available online: (accessed 1 December 2021).
Desjardins, R.L.; Worth, D.E.; Vergé, X.P.C.; Maxime, D.; Dyer, J.; Cerkowniak, D. Carbon footprint of beef cattle. Sustainability 2012, 4, 3279–3301.
Kramer, L. The future of meat is shifting to Plant-Based Products. U of T news, 17 June 2019. Available online: (accessed 4 December 2020).
Byrne, J. Feed Efficiency in Feedlot Production. OMAFRA, 28 February 2018. Available online: (accessed 1 June 2022).
Journal Menu
Journal Contact
Highlights of Sustainability Editorial Office
Highlights of Science
Avenida Madrid, 189-195, 3-3
08014 Barcelona, Spain
Tel. +34 93 138 23 89
Cathy Wang Managing Editor
Submit Your Article
Highlights Sustain., ISSN 2696-628X. Published quarterly by Highlights of Science.
Subscribe to read the latest articles and newsletters from Highlights of Science.