In the discourse of climate urbanism smart, sustainable, and green visions of future city development are increasingly conflating. Environmental metrics, norms, and standards form a new urban growth paradigm and are integrated, as best practices, in urban governance and planning. This chapter aims to understand the dominance of certain ideologies, institutions, and strategies by looking at the C40 Cities network as part of a global discourse coalition with a global ethnography approach and methods of critical discourse analysis. It argues that C40 strategically promotes a green growth paradigm for future cities to endorse market-based, technology-focused solutions to urban infrastructure and public services. We show that city networks like C40 are actively engaging in the standard setting and dissemination of global environmental metrics in a global discourse coalition. C40 works with global think tanks, development finance institutions (DFIs), international organisations (IOs), and multinational corporations that boost climate urbanism as a hegemonic project. This strategy involves the production and exchange of specialised knowledge and expertise on urban infrastructure development, access to institutional funding and private investment mechanisms, as well as the institutionalisation of reporting and accounting standards for carbon emissions in cities.