Μεθοδολογικό πλαίσιο για τον υπολογισμό του ανθρακικού αποτυπώματος και την επίτευξη της ανθρακικής ουδετερότητας σε εταιρείες ύδρευσης & αποχέτευσης στην Ελλάδα

Χατζηγεωργίου, Σταυρούλα

Doctoral Thesis

Author

Χατζηγεωργίου, Σταυρούλα

Date

2025-10-30

Abstract

Climate change constitutes one of the most significant environmental challenges of the modern era. Greenhouse gas (GHG) emissions represent the primary driver behind the increase in global temperatures, the alteration of the hydrological cycle, and the loss of natural ecosystems. Water supply and wastewater plants are directly linked to this phenomenon, as their infrastructure and operation require substantial consumption of energy and fuels, the use of chemical substances, while at the same time producing indirect and direct greenhouse gas emissions through water and wastewater treatment processes. Despite the growing importance of environmental management in the sector, the systematic quantification of carbon emissions and their integration into the strategic planning of water supply and wastewater plants remain limited, particularly with regard to comprehensive and dynamic approaches. This doctoral dissertation aims to develop a theoretical and methodological framework for calculating the carbon footprint of water supply and wastewater plants, utilizing the System Dynamics (SD) methodology. The dissertation establishes a multidimensional framework that combines, on the one hand, international environmental policies and regulatory requirements and, on the other hand, the principles of sustainable development and the circular economy. It includes, of course, the established standards for quantifying greenhouse gas emissions (ISO 14064, GHG Protocol, PAS 2050), as well as the specific operational characteristics of water supply and wastewater plants. In this way, it attempts to bridge the gap between theoretical knowledge, regulatory compliance, and practical decision-support tools for reducing the carbon footprint in the critical sector of water and wastewater services. The dissertation begins with an analysis of the international, European, and national legislative framework for environmental protection and greenhouse gas emission management. It records the main international agreements, such as the United Nations Framework Convention on Climate Change (UNFCCC), the Kyoto Protocol, the Paris Agreement, as well as the evolution of European environmental policies that led to the European Green Deal and the climate targets of the 2022–2030 period. Additionally, it examines the role of sustainable development and the circular economy as a fundamental strategic framework for enterprises in the sector. Within this context, the use of standardized sustainability indicators (GRI, SASB) and the implementation of corporate social responsibility principles significantly enhance environmental transparency and accountability practices. Next, the conceptual background of the carbon footprint is explored, including an analysis of the greenhouse effect, the environmental and socio-economic impacts of climate change, and the methods for quantifying emissions. Particular emphasis is placed on the ISO 14064 and GHG Protocol standards, which provide the foundation for the correct recording, verification, and reporting of emissions at the organizational level, as well as the PAS 2050 method for the life cycle of products and services. The critical assessment of relevant literature demonstrates that, despite the availability of tools for static emission reporting offered by existing methodological approaches, these approaches consistently fail to adequately represent the dynamic and multifaceted nature of water and wastewater operational systems, where emissions are shaped through complex multi-factor interdependencies, time delays, and non-linear relationships among key parameters. To address this complex dynamic behavior, the dissertation develops a methodological framework that includes defining system boundaries, identifying emission sources (Scopes 1, 2, and 3), and quantifying the direct and indirect emissions arising from the operation of water supply and wastewater plants. The study identifies and quantifies emission sources from the use of fuels in pumping stations and treatment plants, fugitive emissions from biological processes, emissions from electricity consumption, staff transportation, sludge production and incineration, as well as CO₂ removals through natural processes. In addition, it examines economic instruments and mechanisms that can support the transition toward carbon neutrality, such as emissions trading systems and guarantees of origin for green energy. The central element of the dissertation is the development of a dynamic model for calculating the carbon footprint using System Dynamics. By employing Causal Loop Diagrams and Stock & Flow Diagrams, this methodological approach enables the dynamic representation of the complex behavior of a greenhouse gas emission management model in water supply and wastewater plants. This approach allows for the visualization of interdependencies among critical parameters, time delays, and feedback loops that shape the overall trajectory of emissions. Thus, it facilitates the identification of optimal intervention strategies for improving the environmental performance of companies. The model is developed at a conceptual level, including the formulation of basic equations, operational parameters, and the potential dynamic effects of different operational scenarios or emission mitigation strategies. It is grounded in documented international practices and standards, offering a reusable framework for future empirical studies. The contribution of this dissertation is structured along three distinct axes. First, it offers theoretical added value by providing an integrated synthesis of international literature, regulatory requirements, and emission calculation methods in the water supply and wastewater sector, consolidating existing knowledge from water and wastewater management, environmental accounting, and dynamic modeling into a unified framework tailored to the needs of the industry. Second, it introduces methodological innovation by proposing a dynamic tool (System Dynamics) for calculating the carbon footprint, capable of supporting strategic decisions for sustainable water management. Finally, it offers practical value by providing water supply and wastewater plants with an adaptable methodological framework for estimating their emissions, with the potential for application across different operational environments and geographical scales. The main findings of the dissertation highlight that greenhouse gas emissions in the water supply and wastewater sector are primarily influenced by energy consumption, fuel use, chemical substances employed in water and wastewater treatment processes, as well as direct and indirect emission sources across the system’s infrastructures. The application of System Dynamics enables the dynamic representation and analysis of relationships among variables that affect the overall emission balance, surpassing the limitations of static quantification methods and contributing to the development of more comprehensive strategies for calculating and managing the carbon footprint. The dissertation concludes by identifying limitations and proposing future research directions, including the empirical application of the model, the integration of advanced machine learning methods and life cycle analysis, as well as the linking of results with carbon market mechanisms and policy-level decision-making systems. Overall, this dissertation provides an innovative theoretical and methodological tool for quantifying and understanding the carbon footprint of water supply and wastewater plants, enhancing their capacity to contribute meaningfully to the global effort to address climate change. In conclusion, the dissertation finds that calculating the carbon footprint through a systemic approach can serve as a key tool for transitioning toward more sustainable, resilient, and low-emission water and wastewater infrastructures. The adoption of such models can strengthen the ability of water utilities to meet international regulatory requirements, support compliance with ISO 14064 and the GHG Protocol, and embed environmental sustainability practices into their operational planning.

Department

Σχολή Οικονομικών, Επιχειρηματικών και Διεθνών Σπουδών. Τμήμα Οργάνωσης και Διοίκησης Επιχειρήσεων

Number of pages

317

Language

Greek

URI

https://dione.lib.unipi.gr/xmlui/handle/unipi/18625

Collections

Τμήμα Οργάνωσης και Διοίκησης Επιχειρήσεων

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Except where otherwise noted, this item's license is described as
Αναφορά Δημιουργού-Μη Εμπορική Χρήση-Όχι Παράγωγα Έργα 3.0 Ελλάδα