  Citation: Mancini, E.; Negro, V.; Mainero, D.; Raggi, A. The Use of a Simplified Carbon Footprint Tool for Organic Waste Managers: Pros and Cons. Sustainability 2022, 14, 1951. https://doi.org/10.3390/su14041951 Academic Editor: Giovanni De Feo Received: 2 December 2021 Accepted: 4 February 2022 Published: 9 February 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). sustainability Article The Use of a Simplified Carbon Footprint Tool for Organic Waste Managers: Pros and Cons Eliana Mancini 1, * , Viviana Negro 2 , Davide Mainero 2 and Andrea Raggi 1 1 Department of Economic Studies, University “G. d’Annunzio”, Viale Pindaro 42, 65127 Pescara, Italy; a.raggi@unich.it 2 ACEA Pinerolese Industriale S.p.a, Via Vigone 42, 10064 Pinerolo, Italy; viviana.negro89@gmail.com (V.N.); Davide.MAINERO@aceapinerolese.it (D.M.) * Correspondence: eliana.mancini@unich.it Abstract: Given that the pressure of climate change action on companies is increasing, it is recom- mended to measure the improvement of mitigation activities in terms of GHG emissions. This paper aims to highlight the still-open aspects that characterise simplified GHG accounting tools, starting from the outcomes of a case study. This study was performed using a simplified Italian software for the CO 2 eq accounting of composting and anaerobic digestion, two mitigation activities that contribute an important share of global GHG emissions reduction. The tool is based on the life-cycle thinking approach. It has been applied to an Italian company that treats the organic fraction of municipal solid waste. The tool analysis has made it possible to stress several issues that are currently the object of debate in the literature, for example, the trade-off between the flexibility of the software and its user friendliness or the multifunctionality issues and their different interpretations. However, focusing on just one impact category, i.e., climate change, may lead to an incomplete picture of the overall environmental performance of the process analysed. Therefore, this tool could be improved by including other impact categories, such as eutrophication and acidification, which may be affected by the studied activities. Keywords: environmental assessment; life-cycle thinking; organic waste; climate change; simpli- fied tools 1. Introduction The role of greenhouse gas (GHG) emissions as a major cause of climate change has long been stressed by the scientific community [1–4] as well as the urgency to make effective decisions [5]. Indeed, systematic and trans-sectoral actions are being undertaken to tackle that issue [4,6]. About 8–10% of global GHG emissions are caused by food that is not consumed [7]. In the European Union, approximately 118 to 138 million tonnes of bio-waste are generated annually, only 40% of which are recycled into high-quality compost and digestate [8]. Therefore, there is a potential not yet utilised. Composting and anaerobic digestion (AD) are considered as mitigation activities for GHG reduction [9] because they decrease landfilling, recover materials, and, in the case of AD, also derives alternative fuels from renewable sources [2]. As stated by Manninen et al. [10], biogas, the fuel deriving from AD, constitutes a significant part of the energy market. The large potential in producing biogas is confirmed by the European Commission [11]. Substituting fossil fuels with renewable energy and thus decarbonising the energy sector [12] can help addressing climate change. Renewable energy promotion is amongst the goals of the European Union’s energy policy [13] and several other international commitments, such as the Paris Agreement [14]. In such a context, it is essential to adopt cleaner technologies aimed at mitigating global warming and, at the same time, to measure their climate performance in order to verify their effectiveness. Sustainability 2022, 14, 1951. https://doi.org/10.3390/su14041951 https://www.mdpi.com/journal/sustainability