Supporting the energy transition of cities towards climate neutrality: a science-based approach

Climate change is now a visible and growing issue that has both short-term and long-term impacts. Increasingly frequent and extreme natural disasters are evidence of ongoing global warming, such as rising sea levels threatening coastal communities or extreme temperatures leading to loss of biodiversity and drought problems. Different scientific studies, as the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), show that the main cause is the increased concentration of greenhouse gases from anthropogenic activities in the atmosphere. Energy policies play a key role in counteracting climate change by finding new, innovative, and effective mitigation and adaptation solutions at different levels: from the international level, where global guidelines are defined, to the national and local levels, where concrete and targeted actions can be implemented. Although this is a global challenge, a crucial role is played by cities as the basic building block of the implementation of these counteracting strategies. In fact, despite occupying 2% of the earth's surface, they are responsible for more than 70% of global emissions and represent a favourable context for implementing targeted and effective actions. Indeed, they offer fertile ground for adopting sustainable technologies, promoting public transport, smart waste management and optimizing energy consumption in buildings. The adoption of science-based approaches is crucial in this field. Advanced scientific methodologies are essential to assess the effectiveness of implemented policies and actions, allowing for real-time analysis of the city's response, from different perspectives. In fact, this approach provides policymakers with the necessary tools to make informed and evidence-based decisions that are fundamental to effectively address climate change, without providing 'preferred pathways' but by constructing “what if” scenarios. In this framework, the aim of the thesis is to evaluate the impacts of decarbonization actions at urban scale, focusing in particular on the stationary energy sector, which appears to be one of the most significant in terms of emissions produced. It is shown that through the implementation of various scenarios, chosen according to different decarbonization trajectories for this sector, it is already possible to obtain remarkable results towards the achievement of cities’ climate neutrality. The proposed methodology has been applied to the case study of Turin, in the context of the collaboration between the Energy Security and Transition (EST) Lab and the Municipality of Turin for drafting the Climate City Contract required by the EU mission "100 Climate-Neutral and Smart Cities by 2030" of the European Commission. The work, therefore, provides a contribution in supporting the sustainability-oriented policy decision making at urban scale, and can represent a starting point for further research activities, aimed at refining the characterisation of the built environment and at enhancing the granularity of its modelling representation.