Why did Tokyo bring 55 global cities to the same table: climate risk is rewriting urban governance

Why Tokyo Brought 55 Global Cities to the Same Table: Climate Risk Is Rewriting Urban Governance

What Tokyo convened this time was not an ordinary international conference, but a draft of the future urban order.

During SusHi Tech Tokyo 2026, 55 cities from five continents pledged to strengthen cooperation, building closer coordination around natural disasters driven by climate change, infrastructure resilience, digital governance, and inclusive development. Seen from the outside, it looks like a multilateral dialogue led by local governments; looking deeper, it reflects a more realistic judgment: after extreme weather, dense populations, fiscal constraints, and aging infrastructure have stacked up, many cities can no longer treat climate risk as merely an environmental issue. They must regard it as a core question of governance capacity, capital allocation, and urban security.

This is also why Tokyo chose this moment to push for an upgrade of G-NETS (Global City Network for Sustainability). In the past, ties between cities were mostly limited to exchanges of experience, friendly visits, and symbolic document signings; today, cities are beginning to build more pragmatic cooperation frameworks around flood control, drainage, power grids, building codes, data systems, and emergency response. In other words, city diplomacy is shifting from “telling a vision” to “building it together.”

Tokyo itself is a typical case of this transformation. The metropolitan government announced that it will accelerate the construction of underground “regulating reservoirs,” aiming to raise total storage capacity to 3.65 million cubic meters by fiscal 2035 to cope with increasingly frequent and intense downpours. This number is not just an engineering metric; it means the center of urban governance is shifting: from post-disaster repair to pre-disaster mitigation, from emergency rescue to risk prevention, and from upgrading isolated facilities to systemic defense.

For major cities around the world, this shift is almost unavoidable. Sea-level rise, wildfires, floods, heat waves, and storms are no longer isolated events, but increasingly resemble a long-term environmental backdrop. At the meeting, Los Angeles emphasized its shift from “disaster response” to “proactive disaster mitigation,” linking its latest climate action plan to a lower-carbon, cleaner urban structure by around 2050; Christchurch, meanwhile, packaged its experience of rebuilding from the ruins of the 2011 earthquake into a replicable “model of urban resilience.” What these two cities share is not that they both suffered disasters, but that they both realized: a city’s true competitiveness is ultimately reflected in the speed of post-disaster recovery, the ability to revise rules, and the quality of the rebuilt urban space.This explains why infrastructure and innovation/startups were discussed together at this Tokyo conference. On the surface, one is heavy-capital public works, while the other is a high-risk startup ecosystem; but in today’s urban governance, the two are no longer separate. Faced with complex climate challenges, governments need not a single mega-project, but end-to-end coordination across sensors, data platforms, risk modeling, emergency dispatch, drainage systems, energy reserves, and community alerts. By jointly promoting “support for and utilization of startups,” the Tokyo participating cities are, in essence, turning the city into an open technological testbed: whoever can turn technology more quickly into implementable, fundable, and maintainable public services is more likely to become the maker of the next round of urban standards.

This is especially evident in Asia. Around the same time, Tokyo also launched a sustainable development dialogue with Southeast Asian capitals, focusing on storm and flood prevention and urban infrastructure development. This choice is highly practical. Southeast Asia is at a stage where urbanization, infrastructure expansion, and climate risk are all rising at once: populations are pouring rapidly into capital areas, coastal and low-lying zones are under pressure, and drainage, transportation, housing, and power supply systems are all facing more fragile weather conditions. Tokyo’s cooperation with these cities is not merely about exporting experience; it is also about competing for the discursive power to define a future urban standard—whoever defines the “resilient city” will shape relevant engineering codes, financing priorities, technology procurement, and city branding.

From this perspective, the value of G-NETS lies not only in the fact that its membership has reached 55 cities, but in the new format of urban collaboration it provides. Multilateral mechanisms at the national level are often constrained by geopolitics and policy disagreements, whereas alliances at the city level are more closely issue-oriented: floods, heatwaves, building safety, public health, transportation, and digital services all require immediate action. What mayors face is not an abstract diplomatic text, but the administrative consequences that will show up immediately in the next torrential rain, the next heatwave, or the next round of energy shortages.

Tokyo Governor Yuriko Koike emphasized that the conference must not stop at discussion and must be translated into action. This may sound simple, but it precisely reveals the new pressure on global urban governance: in an era of shorter political cycles, tighter budgets, and lower public tolerance, city leaders can no longer rely on grand narratives to maintain trust; they must produce measurable results. How much has flood protection improved? How can subways and underground spaces provide earlier warnings? Can elderly people and children be protected during heatwaves? Do new energy facilities truly reduce systemic risk? These are all part of urban legitimacy.

At the same time, this conference also shows a change that is often overlooked: urban competition is no longer centered solely on growth, but increasingly on rebuilding the conditions for “sustainable growth.” In the past, major cities competed on CBD skylines, foreign capital inflows, and headquarters economies; now, they compete on their ability to keep functioning under extreme weather, transparency in data governance, redundancy in infrastructure, and social inclusiveness. Climate resilience is no longer a subsidiary issue, but the underlying condition for attracting capital, stabilizing insurance costs, protecting tourism, and maintaining labor supply.This is also why cities like Helsinki, Glasgow, Hanoi, and Turin were willing to include their own action commitments in the same joint declaration. The problems they face differ, but the direction is the same: cutting emissions, strengthening blue-green networks, improving flood management, building smart government, enhancing inclusiveness, and supporting more sustainable urban living. For investors and the infrastructure sector, this means that over the next decade, urban-related opportunities will be increasingly concentrated in drainage systems, underground space, battery storage, distributed energy, digital emergency response platforms, climate modeling, and urban sensor networks. The technology stack of city governance is being redefined.

But the challenges are equally clear. City alliances are good at reaching consensus, but not necessarily at turning that consensus into long-term execution across years, departments, and budgets. Stricter building codes will raise development costs; underground works and flood-control facilities require many years to recoup investment; and digital governance involves differences in data standards, privacy, and public-sector capacity. The real test is not how many joint declarations are issued after the conference, but whether, three or five years later, these cities are truly more resilient to extreme weather, recover faster, and cause less harm to vulnerable groups during disasters.

By bringing together 55 cities this time, Tokyo is sending a signal for the era: climate adaptation has shifted from an “environmental issue” to part of “urban sovereignty.” The most competitive cities of the future will not necessarily be the most dazzling ones, but the ones best able to maintain order amid chaos, keep functioning under shocks, and quickly rebuild trust after disasters. For the global urban network, this may well be the next stage of public capacity most worth investing in.