Livable Cities - London AMPS | City, University of London Page 85 EU CITY CALCULATOR: ENHANCING CLIMATE ACTION IN EUROPEAN CITIES THROUGH CO-CREATION AND TRANSITION PATHWAYS IN A MODELLING TOOL Author: HECTOR RODRIGUEZ-CHAVEZ1, SANDRA BARBERINO VIGNOLA1, JULIA EPP1, MONIKA ORLOWSKI1, CHRISTIANE WALTER1,2, BEATRICE MONTELEONE3,4, ISABEL RODRIGUEZ5, ORLANDO PARAIBA5 Affiliation: 1 POTSDAM INSTITUTE FOR CLIMATE IMPACT RESEARCH, GERMANY.2 BAUHAUS EARTH, GERMANY.3 UNIVERSITY SCHOOL FOR ADVANCED STUDIES IUSS PAVIA, ITALY.4 ECONOMETRICS SRL, ITALY.5 ENERGY AND ENVIRONMENT AGENCY OF ARRÁBIDA, PORTUGAL. INTRODUCTION Cities are pivotal in combating climate change and promoting sustainable development.1 Urban areas are responsible for 70% of global greenhouse gas (GHG) emissions and 78% of energy consumption, yet they also serve as fertile ground for innovative actors and modern concepts to operate and proliferate,2 positioning them at the forefront of the transition to a low-carbon future. Local governments are essential in implementing policies to meet national climate goals, often showing high ambition to cut emissions. However, many cities face challenges in developing and implementing climate action plans due to financial constraints, increasing complexity and interconnectedness of the urban fabric, lack of capacities, limited sustainability networks, in addition to a variety of political challenges.3 This last category can include resistance to climate policies from key stakeholders, shifts in national climate policy or limited coordination between different levels of government, including urban actors.4 Effective policy coordination among local, regional, and national governments is crucial to leverage cities' roles in accelerating climate transition. In this complex context, broad participation is needed to engage diverse actors and integrate various perspectives for successful transition pathways and science-based policies.5 The European Union (EU) highlights the importance of participation and multi-level dialogues in Article 11 of the Regulation on the Governance of the Energy Union and Climate Action (2018/1999). It recognizes local authorities' critical role in sustainable energy policies, exemplified by initiatives like the Covenant of Mayors (CoM), requiring signatories to create and implement Sustainable Energy and Climate Action Plans (SECAP) to reduce emissions and adapt to climate change. In this context, the EUCityCalc project offers the EU City Calculator, a tool to quantify mitigation potentials and explore decarbonisation pathways. It supports cities in refining climate policy through a co-creation process integrating data and knowledge from multiple stakeholders.6 This article draws on the pilot cities´ co-creation experiences with the EU City Calculator, exploring how transition pathways are used to present, discuss and validate climate policies, and how stakeholders align with