entail targeted actions to reduce the impacts of both human international projects and networking initiatives (for example, lifestyles and consumption patterns on the local environment, the EU City Lighthouse program). And it creates deeper particularly in urban areas. Second, urban environments are economic, social, and cultural ties within cities. This transfer known to be major contributors to various global environmental of experience, knowledge, and expertise goes beyond traditional problems, and cooperation lets cities compare and verify the financial and aid aspects. It also helps cities to get the most relative efficiency of the different instruments, tools, and from one another’s experiences in developing efficient real-life policies that they are using to tackle those problems. For solutions and bringing stability to urban areas. example, increased urban traffic is causing higher CO and2 urban pollution levels. Moreover, high resource consumption Cities have been enlarging the range of nongovernmental and groundwater tapping may cause desertification, or at professionals whom they call upon. Private companies and least a depletion of resources. The solid waste that cities urban stakeholders (such as nongovernmental organizations and produce is leading to increased land occupation, water use, community-based organizations) help them to find sustainable and air pollution. Third, the links between the causes and solutions and transfer knowledge. It is essential for cities to consequences of urban living and urban lifestyles are better expand their knowledge bases, to set up innovative networking, explained by scientific studies. These studies have helped us and to mobilize expertise. Increasing the human resources and to understand why taking local action is a priority and what skillsets allocated to critical urban functions is crucial. capacities cities have to tackle global environmental problems. Cooperation helps to benchmark local solutions. Fourth, cities D- Self-image management, awards, and prizes are suited to being the place where environmental initiatives are pioneered, because they enjoy a demonstrative level of Are people and decision makers sensitive to the reputation of subsidiarity and so can make decisions on a decentralized their city? Economic activities determine the capacity of urban basis. areas to implement affordable and sustainable solutions. The quality of life that a city’s residents experience in their The UCLG acts as a global network of various actors, including city is shaped by a mix of criteria, from proximity to services cities; local, regional, and metropolitan governments; and and ease of mobility to noise levels and air quality. Cities associations connected to governments. Its objective is to are increasingly being subjected to ranking, and the prizes identify and encourage suitable policies to be implemented received (or not) reinforce (or not) their reputation and their at the territorial and city levels.37 In a similar vein, the C40 attractiveness. Cities’ self-recognition of their role in tackling network comprises ninety-seven cities that collectively account urban transformation challenges is leading more and more of for 25 percent of global GDP and are home to a twelfth of the them to manage their image with a view to consolidating or world’s population.38 Based on their assessment that cities changing their reputation. cannot just rely on national governments’ policies, the C40 network’s members acknowledge that “we have reached a Six factors are usually identified to assess city reputation: brand defining moment for our planet. To achieve the goals of the name, economic attractiveness, environmental conditions, Paris Agreement and avoid catastrophic climate change we governance, life and health conditions, and mobility. First, need to act faster and with more urgency than ever before... city policies in part focus on people, and so when most cities Cities... know that achieving this climate-safe future is only manage their branding, they emphasize their educational possible if we act now and in collaboration with other levels of infrastructure, their (artistic or economic) creativity, and the government, businesses, civil society and citizens.”39 inclusive dimension of their local communities. The second factor is predominantly economic; cities tend to promote their C- A new approach for cities: local initiatives potential for innovation and entrepreneurship, as well as the complement national policies success of the activities, including services, that take place within them. The third factor has to do with the environment. Strengthening urban partnerships is essential to cities’ Today’s marked concern for reducing carbon footprints and efforts to transform themselves. Cooperation increases emissions implies a need for buildings that consume less opportunities for local businesses and companies to launch energy and the use of renewable energies in both buildings and projects. Collaborating offers greater local independence as transportation. Achieving these things requires a coordinated well as enhanced decision-making capacities when it comes to vision of urban planning. The fourth factor concerns governance, (37) https://www.uclg.org/en/organisation/about (accessed on 15 March 2021). (38) https://www.c40.org/cities (accessed on 12 March 2021). (39) https://www.c40.org/cities (accessed on 12 March 2021 and 6 June 2021). 39 Quélin and Smadja | HEC PARIS | SMART CITIES | The sustainable program of six leading cities | 2021