Int. J. Global Warming, Vol. 22, No. 2, 2020 235 Copyright © 2020 Inderscience Enterprises Ltd. How to reduce environmental impact of hamburger menu? Serap Nazır Department of Chemical Engineering, Yeditepe University, 34755 Kayisdagi Istanbul, Turkey Fax: +90-212-310-2824 Email: serapcan54@gmail.com Mustafa Özilgen* Department of Food Engineering, Yeditepe University, 34755 Kayisdagi Istanbul, Turkey Fax: +90-212-310-2824 Email: ozilgen.mustafa@gmail.com *Corresponding author Abstract: Hamburgers recently draw huge attention because of their contribution to global warming because of the energy utilised and CO2 emitted during their production. If beef should be replaced with chicken, the chemical fertilisers should be replaced with their microbial counter parts, and electric power should be generated by combusting the restaurant waste, it will be possible to achieve 60% reductions in both energy utilisation and CO2 emissions. If the improvements suggested in this study should be implemented globally, in case of production of 1,000,000 t of hamburger menu, 3.24 × 10 10 MJ less energy would be utilised and 7.35 × 10 9 t less CO2 would be emitted to the atmosphere. Keywords: beef burger menu; chicken burger menu; chemical fertilisers; emission reduction; microbial fertilisers. Reference to this paper should be made as follows: Nazır, S. and Özilgen, M. (2020) ‘How to reduce environmental impact of hamburger menu?’, Int. J. Global Warming, Vol. 22, No. 2, pp.235–254. Biographical notes: Serap Nazır earned a BS in Food Engineering from the Ege University and has PhD in Chemical Engineering from the Yeditepe University. She is a quality control manager in one of the major super market chains in Turkey. She works on improving the sustainability in food production as a major part of her industrial activities. Mustafa Özilgen is a Chemical Engineer and a Professor at Yeditepe University in Turkey. He has BS and MS degrees from the Middle East Technical University (Turkey) and PhD from University of California at Davis (USA). He taught classes at the Middle East Technical University, Massey University (New Zealand) and University of California at Davis (USA) and worked as a consultant at Marmara Research Center (Turkey). He is an author of five books