“Why should my Mayor attend global sustainability events?”

A chat on subnational diplomacy

In recent years, more and more local and regional government leaders are traveling to international environmental conferences, like the annual Climate COPs or the ICLEI World Congress. These meetings provide the opportunity to discuss solutions to global and local challenges. But at the same time, the concrete value of elected leaders’ engagement can at times be difficult to grasp. What is the value for such in-person meetings? How does the community back home benefit?

In this fictitious exchange, an imaginary Mayor answers crucial questions raised by concerned residents. These answers shed light on why city or regional leaders, even for smaller jurisdictions, choose to engage with others in the world to ensure our collective resilience in an ever-changing world.

Resident: Why would a Mayor attend a global event and engage with United Nations processes?

Mayor: From the outside, I understand why these trips may look unnecessary. However, attending global events like the UN Climate Change Conference (COP) and meeting with networks of other cities brings tangible benefits right here to our community. 

COPs and other global conferences are an opportunity to gain knowledge and secure resources for local improvements. Think of it like an ideas marketplace for local and subnational leaders, where we can learn about innovative offerings that we can bring back to our communities. This marketplace offers us the opportunity to connect with international climate funds, private sector partners and various initiatives and projects. Additionally, national governments, universities, and city networks often offer expert knowledge to help cities advance climate solutions. By connecting with potential partners at global climate events, I’m increasing the visibility of our city and helping to bring financial and intellectual resources to our city. Additionally, cities around the world face similar challenges that we do, particularly when it comes to climate change. Exchanging in this global setting is an opportunity to pool together the collective solutions across the world and bring the best ideas back to our community.

Resident: But isn’t speaking with foreign governments the job of national governments? Why is subnational diplomacy important?

Mayor: Yes, national governments traditionally handle diplomacy, but local and regional governments have an increasingly important role to play in international relations, especially on issues like climate change. Cities are where decisions are put into practice, from waste to public transportation and building code enforcement. Cities will need an estimated 4.3 trillion USD every year to transition their communities to a fossil fuel free economy. Yet, in 2023 only 19.3% of that funding demand was fulfilled. City-level leaders must advocate for global financial institutions to consider local governments more seriously in their financing decisions. This is just one example of why subnational voices are relevant in global institutions like the UNFCCC. 

Resident: Can you give examples of successful city diplomacy that benefited local communities?

Mayor: Definitely – let’s talk about water management, an area where city governments play a big role. The Dutch are world renowned for their water management expertise, given that 50% of the Netherlands is less than one feet below sea level. The Dutch embassy regularly meets with U.S. cities up and down the Atlantic Coast to discuss their plans for sea level rise and surviving future hurricanes. When Hoboken, USA rebuilt infrastructure following 2012’s devastating Hurricane Sandy, they leaned on the expertise of Dutch architects and engineers to slow water flows and increase holding capacity. Years later, Hoboken has survived flood events with significantly less damage to the city, and even lent lessons learned to Montego Bay, Jamaica as it recovered from Tropical Storm Beryl in 2024. Hoboken and Montego Bay are paired cities in the Cities Forward peer-exchange initiative, led by the U.S. State Department and ICLEI. 

Resident: Our city is already acting in subnational diplomacy through our sister cities. Why do more?

Mayor: Sister cities are excellent ways to foster sustained relationships with cities around the world, but it is only one tool that can bring global solutions to our community. The first sister cities were established in 1931, and many cities continue to see success with this program, leaning on sister cities for advice during the global pandemic. 

In recent years, cities have also started establishing time-bound, focused agreements with other cities, states or organizations. Focused partnerships allow initiatives to sustain impact through administration turnover, and often lead to more actionable projects with concrete outcomes. Hamburg, Germany is taking this approach, as are the 12 Latin America and the Caribbean (LAC) cities signing cooperation charters with U.S. cities to exchange knowledge on a shared climate issue through ICLEI’s Cities Forward initiative.

Another example comes from the Federal City of Bonn, Germany and its partnership with ICLEI – Local Governments for Sustainability. As part of ICLEI’s GreenClimateCities Program, local governments receive guidance on how to develop city-wide climate action plans and identify priority actions. Bonn developed a comprehensive climate action plan, which also attracted international funding for energy efficiency projects. This resulted in retrofitting public buildings with energy-saving technologies and expanding Bonn’s public transport system, positioning Bonn as a model for mid-sized cities in global climate leadership.

Last, when former President Donald Trump announced the U.S. withdrawal from the Paris Agreement in 20217, many U.S. cities stepped up to fill the leadership gap. Cities like New York, Los Angeles, and Chicago committed to the Paris Agreement’s climate goals, forming alliances like the U.S. Climate Alliance and We Are Still In. These cities continued implementing ambitious local climate actions, reducing emissions and investing in renewable energy, to demonstrate their commitment to global climate efforts (with a clear local benefit) despite the federal government’s decision at the time.

In an increasingly interconnected world, cities cannot afford to remain isolated. By engaging globally, mayors and other local and regional representatives and practitioners are not only securing vital resources for the community but also contributing to global solutions. Subnational diplomacy isn’t just about grand speeches; it’s about bringing home tangible benefits—whether it’s flood protection, sustainable infrastructure, or financial resources. Ultimately, it empowers cities to act where national governments may hesitate, ensuring that local voices shape the future.