Carlos Borrego is Professor Emeritus of Environmental Engineering of the University of Aveiro (UA). He was Minister for Environment and Natural Resources, Vice-Rector for Research & Technology, Director of Department of Environment and Planning (DAO) and Director of IDAD-Institute for Environment and Development (the UA interface unit for Cooperation with Society, providing services to organizations on air pollution, impact assessment and sustainable development). He provides cross-university leadership in research, knowledge exchange and programme development in sustainability, environment and health, towards the circular economy. His work lies at the intersection between cities and technologies and his goal is to build better cities through technology, innovation and citizen participation. He focusses on giving a voice to local communities using technology so they can build an argument to tackle local issues with data and he took advantage of his national and European projects to bring climate action to education and improving sustainable development. Carlos is working for more than 49 years on environmental area, serving Portugal in a number of international scientific boards and committees. So, his systemic view of these scientific areas is reflected in the 72 European and national projects he coordinated and in the research work, which includes more than 900 scientific publications (about 180 SCI papers, 21 books and 45 book chapters) on air quality modelling and management, flow and dispersion in wind tunnel and in the atmosphere, exposure and human health modelling, and in supporting the climate transition with the circular economy. His research has been maintained by many sources, including the FCT, APA, ANI, JRC, EEA, EC Framework Programmes, and his career research and consultancy income is more than EURO 40 million. Carlos' work is at the intersection between urban areas and technologies. He uses a range of pervasive and community sensing applications as a means of calibration and validation, like wind tunnels. This technology is needed to measure airflow to ensure the safety of buildings (against harsh winds or hurricanes) or the wind behaviour around the trees and parks (to study the people´s comfort or to support co-creation, co-design, co-deploy and co-monitoring of the nature-based solutions) and to learn more about the aerodynamics of objects such as buildings, cars, airplanes, trains, etc. The goal is to build better cities through technology, innovation, circular economy and citizen participation. This strategy is supported by policy makers, company presidents and school children to explain and show them, with sensor data and numerical modelling results, how these green infrastructures have multiple positive impacts on the local environment.