Final answer:
Major cities are globally linked through their roles as centers for media, environmental coalitions, and multinational corporations, transcending national political boundaries and exhibiting global influence and interconnectedness.
Step-by-step explanation:
The presence of media hubs, coalitions focusing on specific environmental challenges, and headquarters for multinational corporations in major cities are indicators that such cities are linked globally in ways that transcend national political boundaries. Cities serve as crucial nodes in the global network, integrating economic, political, and cultural activities that span across borders. The concentration of these influential entities within cities facilitates international collaboration, innovation, and decision-making that are not limited by national boundaries.
Cities are not just focal points of local or national significance but are influential at the global level. The advantages of urbanization and economies of scale, such as a large customer base and resources, contribute to their global status. However, the globalization of cities can lead to issues such as traffic congestion, pollution, and an increase in negative activities like crime due to high densities of population and businesses. It is the capacity of cities to manage these challenges while maximizing the benefits that will shape their future in a rapidly globalizing world.